Movement Disorders

PHOENIX – Artificial intelligence (AI) is poised to dramatically alter health care, and it presents opportunities for increased production and automation of some tasks. However, it is prone to error and ‘hallucinations’ despite an authoritative tone, so its conclusions must be verified.

Those were some of the messages from a talk by John Morren, MD, an associate professor of neurology at Case Western Reserve University, Cleveland, who spoke about AI at the 2023 annual meeting of the American Association for Neuromuscular and Electrodiagnostic Medicine (AANEM).

He encouraged attendees to get involved in the conversation of AI, because it is here to stay and will have a big impact on health care. “If we’re not around the table making decisions, decisions will be made for us in our absence and won’t be in our favor,” said Dr. Morren.

He started out his talk by asking if anyone in the room had used AI. After about half raised their hands, he countered that nearly everyone likely had. Voice assistants like SIRI and Alexa, social media with curated feeds, online shopping tools that provide product suggestions, and content recommendations from streaming services like Netflix all rely on AI technology.

Within medicine, AI is already playing a role in various fields, including medical imaging, disease diagnosis, drug discovery and development, predictive analytics, personalized medicine, telemedicine, and health care management.

It also has potential to be used on the job. For example, ChatGPT can generate and refine conversations towards a specific length, format, style, and level of detail. Alternatives include Bing AI from Microsoft, Bard AI from Google, Writesonic, Copy.ai, SpinBot, HIX.AI, and Chatsonic.

Specific to medicine, Consensus is a search engine that uses AI to search for, summarize, and synthesize studies from peer-reviewed literature.
 

Trust, but verify

Dr. Morren presented some specific use cases, including patient education and responses to patient inquiries, as well as generating letters to insurance companies appealing denial of coverage claims. He also showed an example where he asked Bing AI to explain to a patient, at a sixth- to seventh-grade reading level, the red-flag symptoms of myasthenic crisis.

AI can generate summaries of clinical evidence of previous studies. Asked by this reporter how to trust the accuracies of the summaries if the user hasn’t thoroughly read the papers, he acknowledged the imperfection of AI. “I would say that if you’re going to make a decision that you would not have made normally based on the summary that it’s giving, if you can find the fact that you’re anchoring the decision on, go into the article yourself and make sure that it’s well vetted. The AI is just good to tap you on your shoulder and say, ‘hey, just consider this.’ That’s all it is. You should always trust, but verify. If the AI is forcing you to say something new that you would not say, maybe don’t do it – or at least research it to know that it’s the truth and then you elevate yourself and get yourself to the next level.”
 

Limitations

The need to verify can create its own burden, according to one attendee. “I often find I end up spending more time verifying [what ChatGPT has provided]. This seems to take more time than a traditional way of going to PubMed or UpToDate or any of the other human generated consensus way,” he said.

Dr. Morren replied that he wouldn’t recommend using ChatGPT to query medical literature. Instead he recommended Consensus, which only searches the peer-reviewed medical literature.

Another key limitation is that most AI programs are date limited: For example, ChatGPT doesn’t include information after September 2021, though this may change with paid subscriptions. He also starkly warned the audience to never enter sensitive information, including patient identifiers.

There are legal and ethical considerations to AI. Dr. Morren warned against overreliance on AI, as this could undermine compassion and lead to erosion of trust, which makes it important to disclose any use of AI-generated content.

Another attendee raised concerns that AI may be generating research content, including slides for presentations, abstracts, titles, or article text. Dr. Morren said that some organizations, such as the International Committee of Medical Journal Editors, have incorporated AI in their recommendations, stating that authors should disclose any contributions of AI to their publications. However, there is little that can be done to identify AI-generated content, leaving it up to the honor code.

Asked to make predictions about how AI will evolve in the clinic over the next 2-3 years, Dr. Morren suggested that it will likely be embedded in electronic medical records. He anticipated that it will save physicians time so that they can spend more time interacting directly with patients. He quoted Eric Topol, MD, professor of medicine at Scripps Research Translational Institute, La Jolla, Calif., as saying that AI could save 20% of a physician’s time, which could be spent with patients. Dr. Morren saw it differently. “I know where that 20% of time liberated is going to go. I’m going to see 20% more patients. I’m a realist,” he said, to audience laughter.

He also predicted that AI will be found in wearables and devices, allowing health care to expand into the patient’s home in real time. “A lot of what we’re wearing is going to be an extension of the doctor’s office,” he said.

For those hoping for more guidance, Dr. Morren noted that he is the chairman of the professional practice committee of AANEM, and the group will be putting out a position statement within the next couple of months. “It will be a little bit of a blueprint for the path going forward. There are specific things that need to be done. In research, for example, you have to ensure that datasets are diverse enough. To do that we need to have inter-institutional collaboration. We have to ensure patient privacy. Consent for this needs to be a little more explicit because this is a novel area. Those are things that need to be stipulated and ratified through a task force.”

Dr. Morren has no relevant financial disclosures.

PHOENIX – Artificial intelligence (AI) is poised to dramatically alter health care, and it presents opportunities for increased production and automation of some tasks. However, it is prone to error and ‘hallucinations’ despite an authoritative tone, so its conclusions must be verified.

Those were some of the messages from a talk by John Morren, MD, an associate professor of neurology at Case Western Reserve University, Cleveland, who spoke about AI at the 2023 annual meeting of the American Association for Neuromuscular and Electrodiagnostic Medicine (AANEM).

He encouraged attendees to get involved in the conversation of AI, because it is here to stay and will have a big impact on health care. “If we’re not around the table making decisions, decisions will be made for us in our absence and won’t be in our favor,” said Dr. Morren.

He started out his talk by asking if anyone in the room had used AI. After about half raised their hands, he countered that nearly everyone likely had. Voice assistants like SIRI and Alexa, social media with curated feeds, online shopping tools that provide product suggestions, and content recommendations from streaming services like Netflix all rely on AI technology.

Within medicine, AI is already playing a role in various fields, including medical imaging, disease diagnosis, drug discovery and development, predictive analytics, personalized medicine, telemedicine, and health care management.

It also has potential to be used on the job. For example, ChatGPT can generate and refine conversations towards a specific length, format, style, and level of detail. Alternatives include Bing AI from Microsoft, Bard AI from Google, Writesonic, Copy.ai, SpinBot, HIX.AI, and Chatsonic.

Specific to medicine, Consensus is a search engine that uses AI to search for, summarize, and synthesize studies from peer-reviewed literature.
 

Trust, but verify

Dr. Morren presented some specific use cases, including patient education and responses to patient inquiries, as well as generating letters to insurance companies appealing denial of coverage claims. He also showed an example where he asked Bing AI to explain to a patient, at a sixth- to seventh-grade reading level, the red-flag symptoms of myasthenic crisis.

AI can generate summaries of clinical evidence of previous studies. Asked by this reporter how to trust the accuracies of the summaries if the user hasn’t thoroughly read the papers, he acknowledged the imperfection of AI. “I would say that if you’re going to make a decision that you would not have made normally based on the summary that it’s giving, if you can find the fact that you’re anchoring the decision on, go into the article yourself and make sure that it’s well vetted. The AI is just good to tap you on your shoulder and say, ‘hey, just consider this.’ That’s all it is. You should always trust, but verify. If the AI is forcing you to say something new that you would not say, maybe don’t do it – or at least research it to know that it’s the truth and then you elevate yourself and get yourself to the next level.”
 

Limitations

The need to verify can create its own burden, according to one attendee. “I often find I end up spending more time verifying [what ChatGPT has provided]. This seems to take more time than a traditional way of going to PubMed or UpToDate or any of the other human generated consensus way,” he said.

Dr. Morren replied that he wouldn’t recommend using ChatGPT to query medical literature. Instead he recommended Consensus, which only searches the peer-reviewed medical literature.

Another key limitation is that most AI programs are date limited: For example, ChatGPT doesn’t include information after September 2021, though this may change with paid subscriptions. He also starkly warned the audience to never enter sensitive information, including patient identifiers.

There are legal and ethical considerations to AI. Dr. Morren warned against overreliance on AI, as this could undermine compassion and lead to erosion of trust, which makes it important to disclose any use of AI-generated content.

Another attendee raised concerns that AI may be generating research content, including slides for presentations, abstracts, titles, or article text. Dr. Morren said that some organizations, such as the International Committee of Medical Journal Editors, have incorporated AI in their recommendations, stating that authors should disclose any contributions of AI to their publications. However, there is little that can be done to identify AI-generated content, leaving it up to the honor code.

Asked to make predictions about how AI will evolve in the clinic over the next 2-3 years, Dr. Morren suggested that it will likely be embedded in electronic medical records. He anticipated that it will save physicians time so that they can spend more time interacting directly with patients. He quoted Eric Topol, MD, professor of medicine at Scripps Research Translational Institute, La Jolla, Calif., as saying that AI could save 20% of a physician’s time, which could be spent with patients. Dr. Morren saw it differently. “I know where that 20% of time liberated is going to go. I’m going to see 20% more patients. I’m a realist,” he said, to audience laughter.

He also predicted that AI will be found in wearables and devices, allowing health care to expand into the patient’s home in real time. “A lot of what we’re wearing is going to be an extension of the doctor’s office,” he said.

For those hoping for more guidance, Dr. Morren noted that he is the chairman of the professional practice committee of AANEM, and the group will be putting out a position statement within the next couple of months. “It will be a little bit of a blueprint for the path going forward. There are specific things that need to be done. In research, for example, you have to ensure that datasets are diverse enough. To do that we need to have inter-institutional collaboration. We have to ensure patient privacy. Consent for this needs to be a little more explicit because this is a novel area. Those are things that need to be stipulated and ratified through a task force.”

Dr. Morren has no relevant financial disclosures.

PHOENIX – Artificial intelligence (AI) is poised to dramatically alter health care, and it presents opportunities for increased production and automation of some tasks. However, it is prone to error and ‘hallucinations’ despite an authoritative tone, so its conclusions must be verified.

Those were some of the messages from a talk by John Morren, MD, an associate professor of neurology at Case Western Reserve University, Cleveland, who spoke about AI at the 2023 annual meeting of the American Association for Neuromuscular and Electrodiagnostic Medicine (AANEM).

He encouraged attendees to get involved in the conversation of AI, because it is here to stay and will have a big impact on health care. “If we’re not around the table making decisions, decisions will be made for us in our absence and won’t be in our favor,” said Dr. Morren.

He started out his talk by asking if anyone in the room had used AI. After about half raised their hands, he countered that nearly everyone likely had. Voice assistants like SIRI and Alexa, social media with curated feeds, online shopping tools that provide product suggestions, and content recommendations from streaming services like Netflix all rely on AI technology.

Within medicine, AI is already playing a role in various fields, including medical imaging, disease diagnosis, drug discovery and development, predictive analytics, personalized medicine, telemedicine, and health care management.

It also has potential to be used on the job. For example, ChatGPT can generate and refine conversations towards a specific length, format, style, and level of detail. Alternatives include Bing AI from Microsoft, Bard AI from Google, Writesonic, Copy.ai, SpinBot, HIX.AI, and Chatsonic.

Specific to medicine, Consensus is a search engine that uses AI to search for, summarize, and synthesize studies from peer-reviewed literature.
 

Trust, but verify

Dr. Morren presented some specific use cases, including patient education and responses to patient inquiries, as well as generating letters to insurance companies appealing denial of coverage claims. He also showed an example where he asked Bing AI to explain to a patient, at a sixth- to seventh-grade reading level, the red-flag symptoms of myasthenic crisis.

AI can generate summaries of clinical evidence of previous studies. Asked by this reporter how to trust the accuracies of the summaries if the user hasn’t thoroughly read the papers, he acknowledged the imperfection of AI. “I would say that if you’re going to make a decision that you would not have made normally based on the summary that it’s giving, if you can find the fact that you’re anchoring the decision on, go into the article yourself and make sure that it’s well vetted. The AI is just good to tap you on your shoulder and say, ‘hey, just consider this.’ That’s all it is. You should always trust, but verify. If the AI is forcing you to say something new that you would not say, maybe don’t do it – or at least research it to know that it’s the truth and then you elevate yourself and get yourself to the next level.”
 

Limitations

The need to verify can create its own burden, according to one attendee. “I often find I end up spending more time verifying [what ChatGPT has provided]. This seems to take more time than a traditional way of going to PubMed or UpToDate or any of the other human generated consensus way,” he said.

Dr. Morren replied that he wouldn’t recommend using ChatGPT to query medical literature. Instead he recommended Consensus, which only searches the peer-reviewed medical literature.

Another key limitation is that most AI programs are date limited: For example, ChatGPT doesn’t include information after September 2021, though this may change with paid subscriptions. He also starkly warned the audience to never enter sensitive information, including patient identifiers.

There are legal and ethical considerations to AI. Dr. Morren warned against overreliance on AI, as this could undermine compassion and lead to erosion of trust, which makes it important to disclose any use of AI-generated content.

Another attendee raised concerns that AI may be generating research content, including slides for presentations, abstracts, titles, or article text. Dr. Morren said that some organizations, such as the International Committee of Medical Journal Editors, have incorporated AI in their recommendations, stating that authors should disclose any contributions of AI to their publications. However, there is little that can be done to identify AI-generated content, leaving it up to the honor code.

Asked to make predictions about how AI will evolve in the clinic over the next 2-3 years, Dr. Morren suggested that it will likely be embedded in electronic medical records. He anticipated that it will save physicians time so that they can spend more time interacting directly with patients. He quoted Eric Topol, MD, professor of medicine at Scripps Research Translational Institute, La Jolla, Calif., as saying that AI could save 20% of a physician’s time, which could be spent with patients. Dr. Morren saw it differently. “I know where that 20% of time liberated is going to go. I’m going to see 20% more patients. I’m a realist,” he said, to audience laughter.

He also predicted that AI will be found in wearables and devices, allowing health care to expand into the patient’s home in real time. “A lot of what we’re wearing is going to be an extension of the doctor’s office,” he said.

For those hoping for more guidance, Dr. Morren noted that he is the chairman of the professional practice committee of AANEM, and the group will be putting out a position statement within the next couple of months. “It will be a little bit of a blueprint for the path going forward. There are specific things that need to be done. In research, for example, you have to ensure that datasets are diverse enough. To do that we need to have inter-institutional collaboration. We have to ensure patient privacy. Consent for this needs to be a little more explicit because this is a novel area. Those are things that need to be stipulated and ratified through a task force.”

Dr. Morren has no relevant financial disclosures.

A device that stimulates the median nerve and a D1 receptor antagonist are among the promising new treatment approaches for patients with Tourette syndrome (TS), according to an overview of new therapies presented at the XXVI World Congress of Neurology.

One recent study by University of Nottingham researchers showed a wrist-worn stimulating device significantly reduces the frequency and severity of tics – repetitive movements or vocalizations that can occur several times a day.

“Wearable nerve stimulation holds great promise because it will be good across the age spectrum; adults can wear it to work, and children can go to school with it to help them concentrate on their schoolwork, and then they take it off at night,” Eileen Joyce, PhD, MB BChir, professor of neuropsychiatry at the Institute of Neurology, University College London, told this news organization.

Dr. Joyce, who was not part of the study, discussed this and other new advances in tic therapy at the meeting.

About 24% of children will suffer from tics at some point. The prevalence of Tourette syndrome among males is about four times that of females, Dr. Joyce told delegates. She added the typical age of onset is about 7 years with peak severity at about 12 years.

Predictors of tics persisting into adulthood include comorbid attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder, and autism spectrum disorder, said Dr. Joyce, who also discussed the “highly heritable” nature of the syndrome and the numerous related genes identified to date.
 

Current and emerging treatments

Current treatments include psychological therapy, Botox for focal tics, and medications such as antipsychotics. Emerging therapies included deep brain stimulation and the new median nerve stimulation approach.

A study published  earlier this year included 135 patients with moderate to severe tic disorder who were randomly assigned to receive the investigational neuromodulation treatment, a sham treatment, or a wait-list treatment group.

The intervention involves rhythmic pulse trains of median nerve stimulation delivered via a device worn at the wrist. The device was programmed to deliver rhythmic (10 Hz) trains of low-intensity (1-19 mA) electrical stimulation to the median nerve at home once daily, 5 days a week for 4 weeks.

At 4 weeks, tic severity, as measured by the Yale Global Tic Severity Scale-Total Tic Severity Score (YGTSS-TTSS), was reduced by 7.1 points (35% reduction) in the active stimulation group compared to 2.13 points in the sham and 2.11 points in wait-list control groups.

The reduction for active stimulation was substantially larger, clinically meaningful (effect size, 0.5), and statistically significant (P = .02) compared to both the sham stimulation and wait-list control groups, which did not differ from one another.

Tic frequency (tics per minute or TPM) was reduced more in the active than sham stimulation groups (−15.6 TPM vs. −7.7 TPM; P < .03) and the reduction in tic frequency was clinically meaningful (>25% reduction; effect-size, 0.3).

When the active stimulator was turned off, the tics worsened, noted Dr. Joyce.

“The study showed that if you stimulate the median nerve at the wrist, you can train brain oscillations that are linked to the suppression of movement,” Dr. Joyce said. “So based on physiological knowledge, they have developed a median nerve stimulator to entrain cortical rhythms.”
 

Simple and exciting

The new device is “really exciting”, she added. “It’s not invasive and is quite simple to use and could help a lot of people with Tourette syndrome.”

Asked to comment, Alan Carson, MD, consultant neuropsychiatrist and honorary professor of neuropsychiatry, University of Edinburgh, who co-chaired the neuropsychiatry session featuring this presentation, called the device “promising.”

“Deep brain stimulation appears to be very effective but it’s a major procedure, so a simple wearable device seems highly desirable,” Dr. Carson said.

Dr. Joyce also discussed a study on the efficacy of cannabis (nabiximols; Sativex) as an intervention for tic management in males, those with severe tics, and those with comorbid ADHD.

And a new oral medication, ecopipam, a highly selective D1 receptor antagonist, is also raising hopes, said Dr. Joyce, with results from a randomized controlled trial  showing the drug significantly improved tics and had few adverse effects.

Dr. Joyce and Dr. Carson report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

A device that stimulates the median nerve and a D1 receptor antagonist are among the promising new treatment approaches for patients with Tourette syndrome (TS), according to an overview of new therapies presented at the XXVI World Congress of Neurology.

One recent study by University of Nottingham researchers showed a wrist-worn stimulating device significantly reduces the frequency and severity of tics – repetitive movements or vocalizations that can occur several times a day.

“Wearable nerve stimulation holds great promise because it will be good across the age spectrum; adults can wear it to work, and children can go to school with it to help them concentrate on their schoolwork, and then they take it off at night,” Eileen Joyce, PhD, MB BChir, professor of neuropsychiatry at the Institute of Neurology, University College London, told this news organization.

Dr. Joyce, who was not part of the study, discussed this and other new advances in tic therapy at the meeting.

About 24% of children will suffer from tics at some point. The prevalence of Tourette syndrome among males is about four times that of females, Dr. Joyce told delegates. She added the typical age of onset is about 7 years with peak severity at about 12 years.

Predictors of tics persisting into adulthood include comorbid attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder, and autism spectrum disorder, said Dr. Joyce, who also discussed the “highly heritable” nature of the syndrome and the numerous related genes identified to date.
 

Current and emerging treatments

Current treatments include psychological therapy, Botox for focal tics, and medications such as antipsychotics. Emerging therapies included deep brain stimulation and the new median nerve stimulation approach.

A study published  earlier this year included 135 patients with moderate to severe tic disorder who were randomly assigned to receive the investigational neuromodulation treatment, a sham treatment, or a wait-list treatment group.

The intervention involves rhythmic pulse trains of median nerve stimulation delivered via a device worn at the wrist. The device was programmed to deliver rhythmic (10 Hz) trains of low-intensity (1-19 mA) electrical stimulation to the median nerve at home once daily, 5 days a week for 4 weeks.

At 4 weeks, tic severity, as measured by the Yale Global Tic Severity Scale-Total Tic Severity Score (YGTSS-TTSS), was reduced by 7.1 points (35% reduction) in the active stimulation group compared to 2.13 points in the sham and 2.11 points in wait-list control groups.

The reduction for active stimulation was substantially larger, clinically meaningful (effect size, 0.5), and statistically significant (P = .02) compared to both the sham stimulation and wait-list control groups, which did not differ from one another.

Tic frequency (tics per minute or TPM) was reduced more in the active than sham stimulation groups (−15.6 TPM vs. −7.7 TPM; P < .03) and the reduction in tic frequency was clinically meaningful (>25% reduction; effect-size, 0.3).

When the active stimulator was turned off, the tics worsened, noted Dr. Joyce.

“The study showed that if you stimulate the median nerve at the wrist, you can train brain oscillations that are linked to the suppression of movement,” Dr. Joyce said. “So based on physiological knowledge, they have developed a median nerve stimulator to entrain cortical rhythms.”
 

Simple and exciting

The new device is “really exciting”, she added. “It’s not invasive and is quite simple to use and could help a lot of people with Tourette syndrome.”

Asked to comment, Alan Carson, MD, consultant neuropsychiatrist and honorary professor of neuropsychiatry, University of Edinburgh, who co-chaired the neuropsychiatry session featuring this presentation, called the device “promising.”

“Deep brain stimulation appears to be very effective but it’s a major procedure, so a simple wearable device seems highly desirable,” Dr. Carson said.

Dr. Joyce also discussed a study on the efficacy of cannabis (nabiximols; Sativex) as an intervention for tic management in males, those with severe tics, and those with comorbid ADHD.

And a new oral medication, ecopipam, a highly selective D1 receptor antagonist, is also raising hopes, said Dr. Joyce, with results from a randomized controlled trial  showing the drug significantly improved tics and had few adverse effects.

Dr. Joyce and Dr. Carson report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

A device that stimulates the median nerve and a D1 receptor antagonist are among the promising new treatment approaches for patients with Tourette syndrome (TS), according to an overview of new therapies presented at the XXVI World Congress of Neurology.

One recent study by University of Nottingham researchers showed a wrist-worn stimulating device significantly reduces the frequency and severity of tics – repetitive movements or vocalizations that can occur several times a day.

“Wearable nerve stimulation holds great promise because it will be good across the age spectrum; adults can wear it to work, and children can go to school with it to help them concentrate on their schoolwork, and then they take it off at night,” Eileen Joyce, PhD, MB BChir, professor of neuropsychiatry at the Institute of Neurology, University College London, told this news organization.

Dr. Joyce, who was not part of the study, discussed this and other new advances in tic therapy at the meeting.

About 24% of children will suffer from tics at some point. The prevalence of Tourette syndrome among males is about four times that of females, Dr. Joyce told delegates. She added the typical age of onset is about 7 years with peak severity at about 12 years.

Predictors of tics persisting into adulthood include comorbid attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder, and autism spectrum disorder, said Dr. Joyce, who also discussed the “highly heritable” nature of the syndrome and the numerous related genes identified to date.
 

Current and emerging treatments

Current treatments include psychological therapy, Botox for focal tics, and medications such as antipsychotics. Emerging therapies included deep brain stimulation and the new median nerve stimulation approach.

A study published  earlier this year included 135 patients with moderate to severe tic disorder who were randomly assigned to receive the investigational neuromodulation treatment, a sham treatment, or a wait-list treatment group.

The intervention involves rhythmic pulse trains of median nerve stimulation delivered via a device worn at the wrist. The device was programmed to deliver rhythmic (10 Hz) trains of low-intensity (1-19 mA) electrical stimulation to the median nerve at home once daily, 5 days a week for 4 weeks.

At 4 weeks, tic severity, as measured by the Yale Global Tic Severity Scale-Total Tic Severity Score (YGTSS-TTSS), was reduced by 7.1 points (35% reduction) in the active stimulation group compared to 2.13 points in the sham and 2.11 points in wait-list control groups.

The reduction for active stimulation was substantially larger, clinically meaningful (effect size, 0.5), and statistically significant (P = .02) compared to both the sham stimulation and wait-list control groups, which did not differ from one another.

Tic frequency (tics per minute or TPM) was reduced more in the active than sham stimulation groups (−15.6 TPM vs. −7.7 TPM; P < .03) and the reduction in tic frequency was clinically meaningful (>25% reduction; effect-size, 0.3).

When the active stimulator was turned off, the tics worsened, noted Dr. Joyce.

“The study showed that if you stimulate the median nerve at the wrist, you can train brain oscillations that are linked to the suppression of movement,” Dr. Joyce said. “So based on physiological knowledge, they have developed a median nerve stimulator to entrain cortical rhythms.”
 

Simple and exciting

The new device is “really exciting”, she added. “It’s not invasive and is quite simple to use and could help a lot of people with Tourette syndrome.”

Asked to comment, Alan Carson, MD, consultant neuropsychiatrist and honorary professor of neuropsychiatry, University of Edinburgh, who co-chaired the neuropsychiatry session featuring this presentation, called the device “promising.”

“Deep brain stimulation appears to be very effective but it’s a major procedure, so a simple wearable device seems highly desirable,” Dr. Carson said.

Dr. Joyce also discussed a study on the efficacy of cannabis (nabiximols; Sativex) as an intervention for tic management in males, those with severe tics, and those with comorbid ADHD.

And a new oral medication, ecopipam, a highly selective D1 receptor antagonist, is also raising hopes, said Dr. Joyce, with results from a randomized controlled trial  showing the drug significantly improved tics and had few adverse effects.

Dr. Joyce and Dr. Carson report no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The past decade has been a contradictory one for research on Huntington’s disease, marked by breakthroughs in the biology and genetics of this fatal neurodegenerative disease and painful disappointments in trials of novel therapies.
 

What is Huntington’s disease?

Huntington’s disease is caused by a trinucleotide repeat mutation in the huntingtin gene (HTT) and follows an autosomal dominant pattern of inheritance. In people with more than 39 copies of this CAG repeat tract expansion, the HTT protein misfolds to become toxic, with more repeats linked to earlier disease onset and a more severe course.

Huntington’s disease causes loss of neurons in the striatum and disrupts the cortical-striatal-thalamic pathway, a brain circuit that governs movement. Although behavioral symptoms can emerge earlier, signature symptoms – chorea, dystonia, and cognitive abnormalities – usually present at midlife and progress until the patient’s death.

Sampaio_Cristina_NJ_web.jpg

Huntington’s disease affects an estimated 30,000 people in the United States, and an estimated 10-12 people for every 100,000 worldwide – making it rare enough that neurologists who do not specialize in movement disorders might never treat a Huntington’s patient. Yet Huntington’s disease is sufficiently prevalent to attract robust research interest and sustain large registries, which have led to remarkable findings with implications not just for Huntington’s disease but for other diseases as well.

Right now, the only Food and Drug Administration–approved treatments for Huntington’s disease are symptomatic therapies to help temper disturbances of movement, sleep, and emotions. There are two major avenues of investigation into Huntington’s disease modification:

Reduce levels of mutant HTT protein, whether through small molecules, gene therapies, or antisense oligonucleotides (ASOs) that modulate RNA processing. In March 2021, Roche announced the suspension of its phase 3 trial of tominersen, an ASO.¹ Trials of other protein-lowering agents were canceled for lack of target engagement or over safety concerns, in 2021 and 2022, although this approach is still considered viable.

Modify the length of CAG repeats, which involves a more recently encountered mechanism in Huntington’s disease. The strategy is at the preclinical stage. In 2015, a group of scientists reported the game-changing discovery that a large number of genes, associated with some of the same DNA-mismatch repair pathways implicated in cancer, can modify the length of CAG repeats in cells. This gave rise to a new set of therapeutic targets, now being explored.

Neurology Reviews 2023 Rare Neurological Disease Special Report spoke with two frequently collaborating researchers at the forefront of Huntington’s disease science – Cristina Sampaio, MD, PhD, chief medical officer of CHDI Management, Princeton, N.J., and Sarah Tabrizi, MD, PhD, from University College London – about lessons learned from the past several years of Huntington’s disease drug research.

The CHDI Foundation, a nonprofit research organization, was founded in 2003 to facilitate development of Huntington’s disease therapies. Its clinical research platform, Enroll-HD, includes a global registry of some 28,000 patients and a biobank to facilitate biomarker discovery and validation. Dr. Tabrizi’s lab explores Huntington’s disease drug targets in both HTT and DNA mismatch repair, and led two CHDI-funded observational studies, TRACK-HD and TrackOn-HD, to characterize disease progression in people with Huntington’s disease. In 2022, Dr. Tabrizi and Dr. Sampaio were coauthors of a comprehensive review of Huntington’s disease drug development and published a new disease-staging system to help enable trials in presymptomatic Huntington’s disease.

“The story of Huntington’s therapeutics is very informative,” Dr. Sampaio said. “Understanding these mechanisms is relevant for any neurologist – not only for Huntington’s but because they represent a prototype development for a big group of therapies and make us better equipped to think about everything else that is happening in neurology. They’re giving us an understanding of where neurology is going.”
 

Tackling a tricky protein

Most Huntington’s disease research has focused on ways to attack or lower mutant HTT protein. But HTT has proven a tricky target: HTT is a large protein, present in all cells, and known to interact with more than 100 genes. Healthy HTT is critical to fetal development, but its functions in the adult body remain something of a mystery. Almost all people with Huntington’s disease have both wild-type and mutant HTT.

Tominersen, the investigative ASO developed by Roche, works to block translation of the HTT message, leading to a reduction in both healthy and mutant HTT protein. It is delivered by lumbar injection to reach the brain. Upon halting its phase 3 trial of tominersen in 2021, Roche reported that people in the high-dosage treatment group did measurably worse – although it remains unclear whether this was caused by excess protein lowering or an off-target effect. The tominersen program was the first to clearly show that it is possible to lower HTT with an intervention – a critical first step in the development of this class of drugs.

Tabrizi_Sarah_ENG_web.jpg

“I think the problem with the trial was the aggressive loading doses plus exposure-related toxicity,” Dr. Tabrizi said. “Whether that exposure-related toxicity was related to too much wild-type HTT lowering or the proinflammatory effects of the ASO, you can’t yet disentangle.” Roche has not given up: The company is now seeking to test lower dosages of tominersen on a younger subgroup of patients who have fewer CAG repeats, in whom a benefit of protein lowering might be more clearly seen.

Small molecules and gene therapies have also been developed to reduce mutant HTT, although most, as is the case with tominersen, will also reduce healthy protein.

“There is a long and complex debate about how much [lowering] is too much and how much is enough,” Dr. Sampaio said. “And this is a problem that has not been solved.”

Allele-specific therapy. A different class of investigative drugs, called allele-specific therapies, target only mutant HTT, sparing healthy protein. The drugs are tailored to genetic markers, or single-nucleotide polymorphisms (SNPs), that are present in different Huntington’s disease populations worldwide. Because treatments based on SNPs are highly tailored, “you need a new drug for each SNP to cover the global Huntington’s disease population,” Dr. Sampaio said. “This presents challenges from a regulatory perspective, as each drug would have to be evaluated separately.”

Two SNP-based therapies failed clinical trials in 2021, when they did not engage their targets.² A third trial succeeded in lowering mutant HTT while preserving healthy protein and is being evaluated further in the clinic.²

Other strategies have yielded disappointing or mixed results:

A trial of branaplam, a small molecule, was stopped late in 2022 after patients developed peripheral neuropathy.³ Novartis, the drug’s manufacturer, said it would no longer investigate branaplam for Huntington’s disease.

Months earlier, in August 2022, a trial of a gene therapy to lower HTT protein – injected directly into the striatum of the brain – was halted because of adverse events in its high-dosage arm but has since resumed, with some changes to protocol.⁴

In neither case was excess protein-lowering thought to be the cause of safety problems.

DNA repair emerges as a promising target

Scientists have understood, since the 1990s, that the number of excess CAG repeats measured in a blood test is not the sole predictor of the onset of motor symptoms or rate of progression of Huntington’s disease.

Since the early 2000s, researchers have also known that the number of CAG repeats in cells is unstable, both in different tissues and cell types, and over time. People with Huntington’s disease turned out to be genetic mosaics, with varying, changing lengths of CAG repeats in cells. Repeats increase as a person ages, most drastically in the spiny medium neurons of the brain.

The process by which CAG repetitions grow in cells, known as somatic instability, remained poorly understood and little investigated until 2015, when a genomewide association study revealed previously unknown mechanisms.⁵ As it turns out, genes involved in the growth of CAG repeats are related to the DNA mismatch repair pathway, which is also important in cancer.

DNA mismatch repair refers to a complex housekeeping system, involving multiple genes and enzymes, that is fundamental to the functioning of the body as genes are continuously being translated to form proteins. Mismatch repair becomes increasingly error-prone with age: Mistakes that are not repaired become mutations, some of which are irrelevant and others that can be deleterious and lead to cancer.

In Huntington’s disease, enzymes involved in repairing DNA are the same ones that can erroneously add CAG repeats to HTT. A person with Huntington’s disease inherits what can be considered a “dyslexic” DNA repair system, Dr. Sampaio said, that misreads its template and keeps adding CAGs.

After the 2015 genomewide association study, “the DNA mismatch repair pathway became hugely important in Huntington’s disease research, and there is a lot of attention being paid now to its components. The idea is that, if we can intervene in this process, we might stop the somatic instability, the growing of the CAG repetitions, and ameliorate the progression of the disease,” Dr. Sampaio said.

In 2017 Dr. Tabrizi’s team reported that the mismatch repair gene MSH-3 was as a key driver of CAG repeats in people with Huntington’s disease.⁶ “I’m working really closely now with DNA repair scientists who’ve been working in cancer for 20 years. Cancer and repeat expansion diseases have really come together,” Dr. Tabrizi said.

At CHDI’s April 2023 therapeutics conference in Dubrovnik, Croatia, scientists presented findings on how to target MSH-3 and other mechanisms that underlie somatic instability.⁷ (Several drug companies are working on small molecules, ASOs, and other ways to inhibit MSH-3.) Researchers also presented extensively on protein lowering. The two treatment strategies are compatible for Huntington’s disease, Dr. Tabrizi said.

“I think the best way to approach Huntington’s is to target the somatic CAG repeat expansion by inhibiting MSH-3 in some way, and also target HTT lowering – but targeting it at the DNA level, as opposed to clearing the protein,” Dr. Tabrizi said. DNA-centered approaches in preclinical testing include CRISPR gene editing to inactivate mutant HTT and zinc finger proteins that allow selective targeting of DNA to reduce mutant HTT.

Recent findings on the mismatch repair pathway in Huntington’s disease have direct implications for other rare neurologic diseases caused by triplet repeat mutations, including myotonic dystrophy and cerebellar ataxias.

“There is very strong basic fundamental research in Huntington’s disease that doesn’t exist for every disease,” Dr. Sampaio said. “The fact that it is monogenic, and an adult disease that progresses relatively slowly, has made it a good disease to study, a kind of model.”

Huntington’s disease research has also generated research strategies of value in neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. It provided key insights about neurofilament light, a biomarker of neuronal damage, and about the ASO drug class, which is being investigated for its utility treating in a range of diseases.

Previously, Huntington’s disease trial cohorts and registries focused on patients with late symptomatic disease. However, researchers are now pivoting to patients with less-severe disease and to preclinical mutation carriers. “We now know you have to treat early,” Dr. Tabrizi said. “This has implications for the whole field.”

Dr. Sampaio disclosed that she is an employee of CHDI Management, the administrative arm of the CHDI foundation. Dr. Tabrizi disclosed serving as a consultant to Alnylam Pharmaceuticals, Annexon, Ascidian Therapeutics, Arrowhead Pharmaceuticals, Atalanta Therapeutics, Design Therapeutics, F. Hoffmann-La Roche, HCD Economics, IQVIA, Iris Medicine, Latus Bio, LifeEdit, Novartis, Pfizer, Prilenia Therapeutics, PTC Therapeutics, Rgenta Therapeutics, Takeda Pharmaceuticals, uniQure, and Vertex Pharmaceuticals.
 

References

1. Genentech. Genentech Provides Update on Tominersen Program in Manifest Huntington’s Disease. https://www.gene.com/media/press-releases/14902/2021-03-22/genentech-provides-update-on-tominersen-.

2. Wave Life Sciences. Defining a new era of oligonucleotides. https://ir.wavelifesciences.com/news-releases/news-release-details/wave-life-sciences-announces-positive-update-phase-1b2a-select.

3. Novartis. Community update: Status of VIBRANT-HD, the study of branaplam/LMI070 in Huntington’s disease. https://hdsa.org/wp-content/uploads/2022/08/Novartis-FINAL-Community-Letter-8-24-22.pdf.

4. UniQure. Second Quarter 2022 Financial Results. https://uniqure.gcs-web.com/node/10856/pdf.

5. Genetic Modifiers of Huntington’s Disease (GeM-HD) Consortium. Cell. 2015 Jul 30;162(3):516-26. doi: 10.1016/j.cell.2015.07.003.

6. Moss DJH et al. Lancet Neurol. 2017 Sep;16(9):701-11. doi: 10.1016/S1474-4422(17)30161-8.

7. CHDI Foundation. Postcard from Dubrovnik 2023. https://chdifoundation.org/postcard-from-dubrovnik-2023/.

The past decade has been a contradictory one for research on Huntington’s disease, marked by breakthroughs in the biology and genetics of this fatal neurodegenerative disease and painful disappointments in trials of novel therapies.
 

What is Huntington’s disease?

Huntington’s disease is caused by a trinucleotide repeat mutation in the huntingtin gene (HTT) and follows an autosomal dominant pattern of inheritance. In people with more than 39 copies of this CAG repeat tract expansion, the HTT protein misfolds to become toxic, with more repeats linked to earlier disease onset and a more severe course.

Huntington’s disease causes loss of neurons in the striatum and disrupts the cortical-striatal-thalamic pathway, a brain circuit that governs movement. Although behavioral symptoms can emerge earlier, signature symptoms – chorea, dystonia, and cognitive abnormalities – usually present at midlife and progress until the patient’s death.

Sampaio_Cristina_NJ_web.jpg

Huntington’s disease affects an estimated 30,000 people in the United States, and an estimated 10-12 people for every 100,000 worldwide – making it rare enough that neurologists who do not specialize in movement disorders might never treat a Huntington’s patient. Yet Huntington’s disease is sufficiently prevalent to attract robust research interest and sustain large registries, which have led to remarkable findings with implications not just for Huntington’s disease but for other diseases as well.

Right now, the only Food and Drug Administration–approved treatments for Huntington’s disease are symptomatic therapies to help temper disturbances of movement, sleep, and emotions. There are two major avenues of investigation into Huntington’s disease modification:

Reduce levels of mutant HTT protein, whether through small molecules, gene therapies, or antisense oligonucleotides (ASOs) that modulate RNA processing. In March 2021, Roche announced the suspension of its phase 3 trial of tominersen, an ASO.¹ Trials of other protein-lowering agents were canceled for lack of target engagement or over safety concerns, in 2021 and 2022, although this approach is still considered viable.

Modify the length of CAG repeats, which involves a more recently encountered mechanism in Huntington’s disease. The strategy is at the preclinical stage. In 2015, a group of scientists reported the game-changing discovery that a large number of genes, associated with some of the same DNA-mismatch repair pathways implicated in cancer, can modify the length of CAG repeats in cells. This gave rise to a new set of therapeutic targets, now being explored.

Neurology Reviews 2023 Rare Neurological Disease Special Report spoke with two frequently collaborating researchers at the forefront of Huntington’s disease science – Cristina Sampaio, MD, PhD, chief medical officer of CHDI Management, Princeton, N.J., and Sarah Tabrizi, MD, PhD, from University College London – about lessons learned from the past several years of Huntington’s disease drug research.

The CHDI Foundation, a nonprofit research organization, was founded in 2003 to facilitate development of Huntington’s disease therapies. Its clinical research platform, Enroll-HD, includes a global registry of some 28,000 patients and a biobank to facilitate biomarker discovery and validation. Dr. Tabrizi’s lab explores Huntington’s disease drug targets in both HTT and DNA mismatch repair, and led two CHDI-funded observational studies, TRACK-HD and TrackOn-HD, to characterize disease progression in people with Huntington’s disease. In 2022, Dr. Tabrizi and Dr. Sampaio were coauthors of a comprehensive review of Huntington’s disease drug development and published a new disease-staging system to help enable trials in presymptomatic Huntington’s disease.

“The story of Huntington’s therapeutics is very informative,” Dr. Sampaio said. “Understanding these mechanisms is relevant for any neurologist – not only for Huntington’s but because they represent a prototype development for a big group of therapies and make us better equipped to think about everything else that is happening in neurology. They’re giving us an understanding of where neurology is going.”
 

Tackling a tricky protein

Most Huntington’s disease research has focused on ways to attack or lower mutant HTT protein. But HTT has proven a tricky target: HTT is a large protein, present in all cells, and known to interact with more than 100 genes. Healthy HTT is critical to fetal development, but its functions in the adult body remain something of a mystery. Almost all people with Huntington’s disease have both wild-type and mutant HTT.

Tominersen, the investigative ASO developed by Roche, works to block translation of the HTT message, leading to a reduction in both healthy and mutant HTT protein. It is delivered by lumbar injection to reach the brain. Upon halting its phase 3 trial of tominersen in 2021, Roche reported that people in the high-dosage treatment group did measurably worse – although it remains unclear whether this was caused by excess protein lowering or an off-target effect. The tominersen program was the first to clearly show that it is possible to lower HTT with an intervention – a critical first step in the development of this class of drugs.

Tabrizi_Sarah_ENG_web.jpg

“I think the problem with the trial was the aggressive loading doses plus exposure-related toxicity,” Dr. Tabrizi said. “Whether that exposure-related toxicity was related to too much wild-type HTT lowering or the proinflammatory effects of the ASO, you can’t yet disentangle.” Roche has not given up: The company is now seeking to test lower dosages of tominersen on a younger subgroup of patients who have fewer CAG repeats, in whom a benefit of protein lowering might be more clearly seen.

Small molecules and gene therapies have also been developed to reduce mutant HTT, although most, as is the case with tominersen, will also reduce healthy protein.

“There is a long and complex debate about how much [lowering] is too much and how much is enough,” Dr. Sampaio said. “And this is a problem that has not been solved.”

Allele-specific therapy. A different class of investigative drugs, called allele-specific therapies, target only mutant HTT, sparing healthy protein. The drugs are tailored to genetic markers, or single-nucleotide polymorphisms (SNPs), that are present in different Huntington’s disease populations worldwide. Because treatments based on SNPs are highly tailored, “you need a new drug for each SNP to cover the global Huntington’s disease population,” Dr. Sampaio said. “This presents challenges from a regulatory perspective, as each drug would have to be evaluated separately.”

Two SNP-based therapies failed clinical trials in 2021, when they did not engage their targets.² A third trial succeeded in lowering mutant HTT while preserving healthy protein and is being evaluated further in the clinic.²

Other strategies have yielded disappointing or mixed results:

A trial of branaplam, a small molecule, was stopped late in 2022 after patients developed peripheral neuropathy.³ Novartis, the drug’s manufacturer, said it would no longer investigate branaplam for Huntington’s disease.

Months earlier, in August 2022, a trial of a gene therapy to lower HTT protein – injected directly into the striatum of the brain – was halted because of adverse events in its high-dosage arm but has since resumed, with some changes to protocol.⁴

In neither case was excess protein-lowering thought to be the cause of safety problems.

DNA repair emerges as a promising target

Scientists have understood, since the 1990s, that the number of excess CAG repeats measured in a blood test is not the sole predictor of the onset of motor symptoms or rate of progression of Huntington’s disease.

Since the early 2000s, researchers have also known that the number of CAG repeats in cells is unstable, both in different tissues and cell types, and over time. People with Huntington’s disease turned out to be genetic mosaics, with varying, changing lengths of CAG repeats in cells. Repeats increase as a person ages, most drastically in the spiny medium neurons of the brain.

The process by which CAG repetitions grow in cells, known as somatic instability, remained poorly understood and little investigated until 2015, when a genomewide association study revealed previously unknown mechanisms.⁵ As it turns out, genes involved in the growth of CAG repeats are related to the DNA mismatch repair pathway, which is also important in cancer.

DNA mismatch repair refers to a complex housekeeping system, involving multiple genes and enzymes, that is fundamental to the functioning of the body as genes are continuously being translated to form proteins. Mismatch repair becomes increasingly error-prone with age: Mistakes that are not repaired become mutations, some of which are irrelevant and others that can be deleterious and lead to cancer.

In Huntington’s disease, enzymes involved in repairing DNA are the same ones that can erroneously add CAG repeats to HTT. A person with Huntington’s disease inherits what can be considered a “dyslexic” DNA repair system, Dr. Sampaio said, that misreads its template and keeps adding CAGs.

After the 2015 genomewide association study, “the DNA mismatch repair pathway became hugely important in Huntington’s disease research, and there is a lot of attention being paid now to its components. The idea is that, if we can intervene in this process, we might stop the somatic instability, the growing of the CAG repetitions, and ameliorate the progression of the disease,” Dr. Sampaio said.

In 2017 Dr. Tabrizi’s team reported that the mismatch repair gene MSH-3 was as a key driver of CAG repeats in people with Huntington’s disease.⁶ “I’m working really closely now with DNA repair scientists who’ve been working in cancer for 20 years. Cancer and repeat expansion diseases have really come together,” Dr. Tabrizi said.

At CHDI’s April 2023 therapeutics conference in Dubrovnik, Croatia, scientists presented findings on how to target MSH-3 and other mechanisms that underlie somatic instability.⁷ (Several drug companies are working on small molecules, ASOs, and other ways to inhibit MSH-3.) Researchers also presented extensively on protein lowering. The two treatment strategies are compatible for Huntington’s disease, Dr. Tabrizi said.

“I think the best way to approach Huntington’s is to target the somatic CAG repeat expansion by inhibiting MSH-3 in some way, and also target HTT lowering – but targeting it at the DNA level, as opposed to clearing the protein,” Dr. Tabrizi said. DNA-centered approaches in preclinical testing include CRISPR gene editing to inactivate mutant HTT and zinc finger proteins that allow selective targeting of DNA to reduce mutant HTT.

Recent findings on the mismatch repair pathway in Huntington’s disease have direct implications for other rare neurologic diseases caused by triplet repeat mutations, including myotonic dystrophy and cerebellar ataxias.

“There is very strong basic fundamental research in Huntington’s disease that doesn’t exist for every disease,” Dr. Sampaio said. “The fact that it is monogenic, and an adult disease that progresses relatively slowly, has made it a good disease to study, a kind of model.”

Huntington’s disease research has also generated research strategies of value in neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. It provided key insights about neurofilament light, a biomarker of neuronal damage, and about the ASO drug class, which is being investigated for its utility treating in a range of diseases.

Previously, Huntington’s disease trial cohorts and registries focused on patients with late symptomatic disease. However, researchers are now pivoting to patients with less-severe disease and to preclinical mutation carriers. “We now know you have to treat early,” Dr. Tabrizi said. “This has implications for the whole field.”

Dr. Sampaio disclosed that she is an employee of CHDI Management, the administrative arm of the CHDI foundation. Dr. Tabrizi disclosed serving as a consultant to Alnylam Pharmaceuticals, Annexon, Ascidian Therapeutics, Arrowhead Pharmaceuticals, Atalanta Therapeutics, Design Therapeutics, F. Hoffmann-La Roche, HCD Economics, IQVIA, Iris Medicine, Latus Bio, LifeEdit, Novartis, Pfizer, Prilenia Therapeutics, PTC Therapeutics, Rgenta Therapeutics, Takeda Pharmaceuticals, uniQure, and Vertex Pharmaceuticals.
 

References

1. Genentech. Genentech Provides Update on Tominersen Program in Manifest Huntington’s Disease. https://www.gene.com/media/press-releases/14902/2021-03-22/genentech-provides-update-on-tominersen-.

2. Wave Life Sciences. Defining a new era of oligonucleotides. https://ir.wavelifesciences.com/news-releases/news-release-details/wave-life-sciences-announces-positive-update-phase-1b2a-select.

3. Novartis. Community update: Status of VIBRANT-HD, the study of branaplam/LMI070 in Huntington’s disease. https://hdsa.org/wp-content/uploads/2022/08/Novartis-FINAL-Community-Letter-8-24-22.pdf.

4. UniQure. Second Quarter 2022 Financial Results. https://uniqure.gcs-web.com/node/10856/pdf.

5. Genetic Modifiers of Huntington’s Disease (GeM-HD) Consortium. Cell. 2015 Jul 30;162(3):516-26. doi: 10.1016/j.cell.2015.07.003.

6. Moss DJH et al. Lancet Neurol. 2017 Sep;16(9):701-11. doi: 10.1016/S1474-4422(17)30161-8.

7. CHDI Foundation. Postcard from Dubrovnik 2023. https://chdifoundation.org/postcard-from-dubrovnik-2023/.

The past decade has been a contradictory one for research on Huntington’s disease, marked by breakthroughs in the biology and genetics of this fatal neurodegenerative disease and painful disappointments in trials of novel therapies.
 

What is Huntington’s disease?

Huntington’s disease is caused by a trinucleotide repeat mutation in the huntingtin gene (HTT) and follows an autosomal dominant pattern of inheritance. In people with more than 39 copies of this CAG repeat tract expansion, the HTT protein misfolds to become toxic, with more repeats linked to earlier disease onset and a more severe course.

Huntington’s disease causes loss of neurons in the striatum and disrupts the cortical-striatal-thalamic pathway, a brain circuit that governs movement. Although behavioral symptoms can emerge earlier, signature symptoms – chorea, dystonia, and cognitive abnormalities – usually present at midlife and progress until the patient’s death.

Sampaio_Cristina_NJ_web.jpg

Huntington’s disease affects an estimated 30,000 people in the United States, and an estimated 10-12 people for every 100,000 worldwide – making it rare enough that neurologists who do not specialize in movement disorders might never treat a Huntington’s patient. Yet Huntington’s disease is sufficiently prevalent to attract robust research interest and sustain large registries, which have led to remarkable findings with implications not just for Huntington’s disease but for other diseases as well.

Right now, the only Food and Drug Administration–approved treatments for Huntington’s disease are symptomatic therapies to help temper disturbances of movement, sleep, and emotions. There are two major avenues of investigation into Huntington’s disease modification:

Reduce levels of mutant HTT protein, whether through small molecules, gene therapies, or antisense oligonucleotides (ASOs) that modulate RNA processing. In March 2021, Roche announced the suspension of its phase 3 trial of tominersen, an ASO.¹ Trials of other protein-lowering agents were canceled for lack of target engagement or over safety concerns, in 2021 and 2022, although this approach is still considered viable.

Modify the length of CAG repeats, which involves a more recently encountered mechanism in Huntington’s disease. The strategy is at the preclinical stage. In 2015, a group of scientists reported the game-changing discovery that a large number of genes, associated with some of the same DNA-mismatch repair pathways implicated in cancer, can modify the length of CAG repeats in cells. This gave rise to a new set of therapeutic targets, now being explored.

Neurology Reviews 2023 Rare Neurological Disease Special Report spoke with two frequently collaborating researchers at the forefront of Huntington’s disease science – Cristina Sampaio, MD, PhD, chief medical officer of CHDI Management, Princeton, N.J., and Sarah Tabrizi, MD, PhD, from University College London – about lessons learned from the past several years of Huntington’s disease drug research.

The CHDI Foundation, a nonprofit research organization, was founded in 2003 to facilitate development of Huntington’s disease therapies. Its clinical research platform, Enroll-HD, includes a global registry of some 28,000 patients and a biobank to facilitate biomarker discovery and validation. Dr. Tabrizi’s lab explores Huntington’s disease drug targets in both HTT and DNA mismatch repair, and led two CHDI-funded observational studies, TRACK-HD and TrackOn-HD, to characterize disease progression in people with Huntington’s disease. In 2022, Dr. Tabrizi and Dr. Sampaio were coauthors of a comprehensive review of Huntington’s disease drug development and published a new disease-staging system to help enable trials in presymptomatic Huntington’s disease.

“The story of Huntington’s therapeutics is very informative,” Dr. Sampaio said. “Understanding these mechanisms is relevant for any neurologist – not only for Huntington’s but because they represent a prototype development for a big group of therapies and make us better equipped to think about everything else that is happening in neurology. They’re giving us an understanding of where neurology is going.”
 

Tackling a tricky protein

Most Huntington’s disease research has focused on ways to attack or lower mutant HTT protein. But HTT has proven a tricky target: HTT is a large protein, present in all cells, and known to interact with more than 100 genes. Healthy HTT is critical to fetal development, but its functions in the adult body remain something of a mystery. Almost all people with Huntington’s disease have both wild-type and mutant HTT.

Tominersen, the investigative ASO developed by Roche, works to block translation of the HTT message, leading to a reduction in both healthy and mutant HTT protein. It is delivered by lumbar injection to reach the brain. Upon halting its phase 3 trial of tominersen in 2021, Roche reported that people in the high-dosage treatment group did measurably worse – although it remains unclear whether this was caused by excess protein lowering or an off-target effect. The tominersen program was the first to clearly show that it is possible to lower HTT with an intervention – a critical first step in the development of this class of drugs.

Tabrizi_Sarah_ENG_web.jpg

“I think the problem with the trial was the aggressive loading doses plus exposure-related toxicity,” Dr. Tabrizi said. “Whether that exposure-related toxicity was related to too much wild-type HTT lowering or the proinflammatory effects of the ASO, you can’t yet disentangle.” Roche has not given up: The company is now seeking to test lower dosages of tominersen on a younger subgroup of patients who have fewer CAG repeats, in whom a benefit of protein lowering might be more clearly seen.

Small molecules and gene therapies have also been developed to reduce mutant HTT, although most, as is the case with tominersen, will also reduce healthy protein.

“There is a long and complex debate about how much [lowering] is too much and how much is enough,” Dr. Sampaio said. “And this is a problem that has not been solved.”

Allele-specific therapy. A different class of investigative drugs, called allele-specific therapies, target only mutant HTT, sparing healthy protein. The drugs are tailored to genetic markers, or single-nucleotide polymorphisms (SNPs), that are present in different Huntington’s disease populations worldwide. Because treatments based on SNPs are highly tailored, “you need a new drug for each SNP to cover the global Huntington’s disease population,” Dr. Sampaio said. “This presents challenges from a regulatory perspective, as each drug would have to be evaluated separately.”

Two SNP-based therapies failed clinical trials in 2021, when they did not engage their targets.² A third trial succeeded in lowering mutant HTT while preserving healthy protein and is being evaluated further in the clinic.²

Other strategies have yielded disappointing or mixed results:

A trial of branaplam, a small molecule, was stopped late in 2022 after patients developed peripheral neuropathy.³ Novartis, the drug’s manufacturer, said it would no longer investigate branaplam for Huntington’s disease.

Months earlier, in August 2022, a trial of a gene therapy to lower HTT protein – injected directly into the striatum of the brain – was halted because of adverse events in its high-dosage arm but has since resumed, with some changes to protocol.⁴

In neither case was excess protein-lowering thought to be the cause of safety problems.

DNA repair emerges as a promising target

Scientists have understood, since the 1990s, that the number of excess CAG repeats measured in a blood test is not the sole predictor of the onset of motor symptoms or rate of progression of Huntington’s disease.

Since the early 2000s, researchers have also known that the number of CAG repeats in cells is unstable, both in different tissues and cell types, and over time. People with Huntington’s disease turned out to be genetic mosaics, with varying, changing lengths of CAG repeats in cells. Repeats increase as a person ages, most drastically in the spiny medium neurons of the brain.

The process by which CAG repetitions grow in cells, known as somatic instability, remained poorly understood and little investigated until 2015, when a genomewide association study revealed previously unknown mechanisms.⁵ As it turns out, genes involved in the growth of CAG repeats are related to the DNA mismatch repair pathway, which is also important in cancer.

DNA mismatch repair refers to a complex housekeeping system, involving multiple genes and enzymes, that is fundamental to the functioning of the body as genes are continuously being translated to form proteins. Mismatch repair becomes increasingly error-prone with age: Mistakes that are not repaired become mutations, some of which are irrelevant and others that can be deleterious and lead to cancer.

In Huntington’s disease, enzymes involved in repairing DNA are the same ones that can erroneously add CAG repeats to HTT. A person with Huntington’s disease inherits what can be considered a “dyslexic” DNA repair system, Dr. Sampaio said, that misreads its template and keeps adding CAGs.

After the 2015 genomewide association study, “the DNA mismatch repair pathway became hugely important in Huntington’s disease research, and there is a lot of attention being paid now to its components. The idea is that, if we can intervene in this process, we might stop the somatic instability, the growing of the CAG repetitions, and ameliorate the progression of the disease,” Dr. Sampaio said.

In 2017 Dr. Tabrizi’s team reported that the mismatch repair gene MSH-3 was as a key driver of CAG repeats in people with Huntington’s disease.⁶ “I’m working really closely now with DNA repair scientists who’ve been working in cancer for 20 years. Cancer and repeat expansion diseases have really come together,” Dr. Tabrizi said.

At CHDI’s April 2023 therapeutics conference in Dubrovnik, Croatia, scientists presented findings on how to target MSH-3 and other mechanisms that underlie somatic instability.⁷ (Several drug companies are working on small molecules, ASOs, and other ways to inhibit MSH-3.) Researchers also presented extensively on protein lowering. The two treatment strategies are compatible for Huntington’s disease, Dr. Tabrizi said.

“I think the best way to approach Huntington’s is to target the somatic CAG repeat expansion by inhibiting MSH-3 in some way, and also target HTT lowering – but targeting it at the DNA level, as opposed to clearing the protein,” Dr. Tabrizi said. DNA-centered approaches in preclinical testing include CRISPR gene editing to inactivate mutant HTT and zinc finger proteins that allow selective targeting of DNA to reduce mutant HTT.

Recent findings on the mismatch repair pathway in Huntington’s disease have direct implications for other rare neurologic diseases caused by triplet repeat mutations, including myotonic dystrophy and cerebellar ataxias.

“There is very strong basic fundamental research in Huntington’s disease that doesn’t exist for every disease,” Dr. Sampaio said. “The fact that it is monogenic, and an adult disease that progresses relatively slowly, has made it a good disease to study, a kind of model.”

Huntington’s disease research has also generated research strategies of value in neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. It provided key insights about neurofilament light, a biomarker of neuronal damage, and about the ASO drug class, which is being investigated for its utility treating in a range of diseases.

Previously, Huntington’s disease trial cohorts and registries focused on patients with late symptomatic disease. However, researchers are now pivoting to patients with less-severe disease and to preclinical mutation carriers. “We now know you have to treat early,” Dr. Tabrizi said. “This has implications for the whole field.”

Dr. Sampaio disclosed that she is an employee of CHDI Management, the administrative arm of the CHDI foundation. Dr. Tabrizi disclosed serving as a consultant to Alnylam Pharmaceuticals, Annexon, Ascidian Therapeutics, Arrowhead Pharmaceuticals, Atalanta Therapeutics, Design Therapeutics, F. Hoffmann-La Roche, HCD Economics, IQVIA, Iris Medicine, Latus Bio, LifeEdit, Novartis, Pfizer, Prilenia Therapeutics, PTC Therapeutics, Rgenta Therapeutics, Takeda Pharmaceuticals, uniQure, and Vertex Pharmaceuticals.
 

References

1. Genentech. Genentech Provides Update on Tominersen Program in Manifest Huntington’s Disease. https://www.gene.com/media/press-releases/14902/2021-03-22/genentech-provides-update-on-tominersen-.

2. Wave Life Sciences. Defining a new era of oligonucleotides. https://ir.wavelifesciences.com/news-releases/news-release-details/wave-life-sciences-announces-positive-update-phase-1b2a-select.

3. Novartis. Community update: Status of VIBRANT-HD, the study of branaplam/LMI070 in Huntington’s disease. https://hdsa.org/wp-content/uploads/2022/08/Novartis-FINAL-Community-Letter-8-24-22.pdf.

4. UniQure. Second Quarter 2022 Financial Results. https://uniqure.gcs-web.com/node/10856/pdf.

5. Genetic Modifiers of Huntington’s Disease (GeM-HD) Consortium. Cell. 2015 Jul 30;162(3):516-26. doi: 10.1016/j.cell.2015.07.003.

6. Moss DJH et al. Lancet Neurol. 2017 Sep;16(9):701-11. doi: 10.1016/S1474-4422(17)30161-8.

7. CHDI Foundation. Postcard from Dubrovnik 2023. https://chdifoundation.org/postcard-from-dubrovnik-2023/.

This transcript has been edited for clarity.

On May 3, 2023, Surgeon General Vivek Murthy issued an advisory raising an alarm about what he called an “epidemic of loneliness” in the United States.

Now, I am not saying that Vivek Murthy read my book, “How Medicine Works and When It Doesn’t” – released in January and available in bookstores now – where, in chapter 11, I call attention to the problem of loneliness and its relationship to the exponential rise in deaths of despair. But Vivek, if you did, let me know. I could use the publicity.

No, of course the idea that loneliness is a public health issue is not new, but I’m glad to see it finally getting attention. At this point, studies have linked loneliness to heart disease, stroke, dementia, and premature death. And now, according to a new study, loneliness may be linked to Parkinson’s disease.

The UK Biobank is really a treasure trove of data for epidemiologists. I must see three to four studies a week coming out of this mega-dataset. This one, appearing in JAMA Neurology, caught my eye for its focus specifically on loneliness as a risk factor – something I’m hoping to see more of in the future.

The study examines data from just under 500,000 individuals in the United Kingdom who answered a survey including the question “Do you often feel lonely?” between 2006 and 2010; 18.4% of people answered yes. Individuals’ electronic health record data were then monitored over time to see who would get a new diagnosis code consistent with Parkinson’s disease. Through 2021, 2822 people did – that’s just over half a percent.

So, now we do the statistics thing. Of the nonlonely folks, 2,273 went on to develop Parkinson’s disease. Of those who said they often feel lonely, 549 people did. The raw numbers here, to be honest, aren’t that compelling. Lonely people had an absolute risk for Parkinson’s disease about 0.03% higher than that of nonlonely people. Put another way, you’d need to take over 3,000 lonely souls and make them not lonely to prevent 1 case of Parkinson’s disease.

Still, the costs of loneliness are not measured exclusively in Parkinson’s disease, and I would argue that the real risks here come from other sources: alcohol abuse, drug abuse, and suicide. Nevertheless, the weak but significant association with Parkinson’s disease reminds us that loneliness is a neurologic phenomenon. There is something about social connection that affects our brain in a way that is not just spiritual; it is actually biological.

Of course, people who say they are often lonely are different in other ways from people who report not being lonely. Lonely people, in this dataset, were younger, more likely to be female, less likely to have a college degree, in worse physical health, and engaged in more high-risk health behaviors like smoking.

The authors adjusted for all of these factors and found that, on the relative scale, lonely people were still about 20%-30% more likely to develop Parkinson’s disease.

165350_table1.PNG

F. Perry Wilson, MD, MSCE, is an associate professor of medicine and public health and director of Yale University’s Clinical and Translational Research Accelerator in New Haven, Conn. He reported no relevant conflicts of interest.
 

A version of this article first appeared on Medscape.com.

This transcript has been edited for clarity.

On May 3, 2023, Surgeon General Vivek Murthy issued an advisory raising an alarm about what he called an “epidemic of loneliness” in the United States.

Now, I am not saying that Vivek Murthy read my book, “How Medicine Works and When It Doesn’t” – released in January and available in bookstores now – where, in chapter 11, I call attention to the problem of loneliness and its relationship to the exponential rise in deaths of despair. But Vivek, if you did, let me know. I could use the publicity.

No, of course the idea that loneliness is a public health issue is not new, but I’m glad to see it finally getting attention. At this point, studies have linked loneliness to heart disease, stroke, dementia, and premature death. And now, according to a new study, loneliness may be linked to Parkinson’s disease.

The UK Biobank is really a treasure trove of data for epidemiologists. I must see three to four studies a week coming out of this mega-dataset. This one, appearing in JAMA Neurology, caught my eye for its focus specifically on loneliness as a risk factor – something I’m hoping to see more of in the future.

The study examines data from just under 500,000 individuals in the United Kingdom who answered a survey including the question “Do you often feel lonely?” between 2006 and 2010; 18.4% of people answered yes. Individuals’ electronic health record data were then monitored over time to see who would get a new diagnosis code consistent with Parkinson’s disease. Through 2021, 2822 people did – that’s just over half a percent.

So, now we do the statistics thing. Of the nonlonely folks, 2,273 went on to develop Parkinson’s disease. Of those who said they often feel lonely, 549 people did. The raw numbers here, to be honest, aren’t that compelling. Lonely people had an absolute risk for Parkinson’s disease about 0.03% higher than that of nonlonely people. Put another way, you’d need to take over 3,000 lonely souls and make them not lonely to prevent 1 case of Parkinson’s disease.

Still, the costs of loneliness are not measured exclusively in Parkinson’s disease, and I would argue that the real risks here come from other sources: alcohol abuse, drug abuse, and suicide. Nevertheless, the weak but significant association with Parkinson’s disease reminds us that loneliness is a neurologic phenomenon. There is something about social connection that affects our brain in a way that is not just spiritual; it is actually biological.

Of course, people who say they are often lonely are different in other ways from people who report not being lonely. Lonely people, in this dataset, were younger, more likely to be female, less likely to have a college degree, in worse physical health, and engaged in more high-risk health behaviors like smoking.

The authors adjusted for all of these factors and found that, on the relative scale, lonely people were still about 20%-30% more likely to develop Parkinson’s disease.

165350_table1.PNG

F. Perry Wilson, MD, MSCE, is an associate professor of medicine and public health and director of Yale University’s Clinical and Translational Research Accelerator in New Haven, Conn. He reported no relevant conflicts of interest.
 

A version of this article first appeared on Medscape.com.

This transcript has been edited for clarity.

On May 3, 2023, Surgeon General Vivek Murthy issued an advisory raising an alarm about what he called an “epidemic of loneliness” in the United States.

Now, I am not saying that Vivek Murthy read my book, “How Medicine Works and When It Doesn’t” – released in January and available in bookstores now – where, in chapter 11, I call attention to the problem of loneliness and its relationship to the exponential rise in deaths of despair. But Vivek, if you did, let me know. I could use the publicity.

No, of course the idea that loneliness is a public health issue is not new, but I’m glad to see it finally getting attention. At this point, studies have linked loneliness to heart disease, stroke, dementia, and premature death. And now, according to a new study, loneliness may be linked to Parkinson’s disease.

The UK Biobank is really a treasure trove of data for epidemiologists. I must see three to four studies a week coming out of this mega-dataset. This one, appearing in JAMA Neurology, caught my eye for its focus specifically on loneliness as a risk factor – something I’m hoping to see more of in the future.

The study examines data from just under 500,000 individuals in the United Kingdom who answered a survey including the question “Do you often feel lonely?” between 2006 and 2010; 18.4% of people answered yes. Individuals’ electronic health record data were then monitored over time to see who would get a new diagnosis code consistent with Parkinson’s disease. Through 2021, 2822 people did – that’s just over half a percent.

So, now we do the statistics thing. Of the nonlonely folks, 2,273 went on to develop Parkinson’s disease. Of those who said they often feel lonely, 549 people did. The raw numbers here, to be honest, aren’t that compelling. Lonely people had an absolute risk for Parkinson’s disease about 0.03% higher than that of nonlonely people. Put another way, you’d need to take over 3,000 lonely souls and make them not lonely to prevent 1 case of Parkinson’s disease.

Still, the costs of loneliness are not measured exclusively in Parkinson’s disease, and I would argue that the real risks here come from other sources: alcohol abuse, drug abuse, and suicide. Nevertheless, the weak but significant association with Parkinson’s disease reminds us that loneliness is a neurologic phenomenon. There is something about social connection that affects our brain in a way that is not just spiritual; it is actually biological.

Of course, people who say they are often lonely are different in other ways from people who report not being lonely. Lonely people, in this dataset, were younger, more likely to be female, less likely to have a college degree, in worse physical health, and engaged in more high-risk health behaviors like smoking.

The authors adjusted for all of these factors and found that, on the relative scale, lonely people were still about 20%-30% more likely to develop Parkinson’s disease.

165350_table1.PNG

F. Perry Wilson, MD, MSCE, is an associate professor of medicine and public health and director of Yale University’s Clinical and Translational Research Accelerator in New Haven, Conn. He reported no relevant conflicts of interest.
 

A version of this article first appeared on Medscape.com.

TOPLINE:

Cerebral palsy (CP) affects 1-4 per 1,000 live births in the United States. A new cohort study found children conceived during the winter and spring months appear to have a slightly higher risk for developing CP than those conceived during the summer. Fall months carried about the same or only slightly higher risk of CP than summer months.

METHODOLOGY:

• Researchers examined data from nearly 4.5 million live births registered in California between 2007 and 2015, exploring if the season of conception could serve as an indicator of exposure to environmental risk factors.
• For instance, infants conceived in winter months may have higher exposure to viruses like influenza. In California, agricultural pesticides are most often applied in summer months, when pregnant people would be in their first or second trimester and receive their most exposure to the fine particulates, the authors hypothesize.
• Almost 4,700 babies in the study population were diagnosed with CP. Researchers also considered the role of preterm birth as a potential mediating factor, and adjusted for sociodemographic characteristics such as maternal age, race, education, smoking during pregnancy, and body mass index.

TAKEAWAY:

• The study found that children conceived in winter and spring had a 9% (95% confidence interval, 1.01-1.19) to 10% (95% CI, 1.02-1.20) higher risk of developing CP than those conceived in the summer.
• Children conceived in January, February, or May carried a 15% higher risk, compared with babies conceived in July.
• The risk was more pronounced among mothers with low education levels or living in neighborhoods where residents have high rates of unemployment, single-parent households, multiunit households, and lower rates of high school graduates.

IN PRACTICE:

The researchers noted that possible explanations for the seasonal link to CP risk may include the prevalence of maternal infections during pregnancy, variations in exposure to pesticides, and seasonal patterns for air pollution. “Investigating seasonal variations in disease occurrence can provide clues about etiologically relevant factors.”

SOURCE:

Lead author Haoran Zhou, MPH, Yale University, New Haven, Conn., and colleagues published their findings online in JAMA Network Open. The study was partly supported by a grant from the American Academy for Cerebral Palsy and Developmental Medicine.

LIMITATIONS:

The study may not have fully captured all children with CP in the cohort due to the possibility of misclassification. The findings may not be generalizable beyond California. The overall increased risk associated with the season of conception was relatively small, suggesting family planning strategies may not need to change based on these findings. The exact mechanisms involving potential environmental factors need further investigation.

DISCLOSURES:

The authors reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

TOPLINE:

Cerebral palsy (CP) affects 1-4 per 1,000 live births in the United States. A new cohort study found children conceived during the winter and spring months appear to have a slightly higher risk for developing CP than those conceived during the summer. Fall months carried about the same or only slightly higher risk of CP than summer months.

METHODOLOGY:

• Researchers examined data from nearly 4.5 million live births registered in California between 2007 and 2015, exploring if the season of conception could serve as an indicator of exposure to environmental risk factors.
• For instance, infants conceived in winter months may have higher exposure to viruses like influenza. In California, agricultural pesticides are most often applied in summer months, when pregnant people would be in their first or second trimester and receive their most exposure to the fine particulates, the authors hypothesize.
• Almost 4,700 babies in the study population were diagnosed with CP. Researchers also considered the role of preterm birth as a potential mediating factor, and adjusted for sociodemographic characteristics such as maternal age, race, education, smoking during pregnancy, and body mass index.

TAKEAWAY:

• The study found that children conceived in winter and spring had a 9% (95% confidence interval, 1.01-1.19) to 10% (95% CI, 1.02-1.20) higher risk of developing CP than those conceived in the summer.
• Children conceived in January, February, or May carried a 15% higher risk, compared with babies conceived in July.
• The risk was more pronounced among mothers with low education levels or living in neighborhoods where residents have high rates of unemployment, single-parent households, multiunit households, and lower rates of high school graduates.

IN PRACTICE:

The researchers noted that possible explanations for the seasonal link to CP risk may include the prevalence of maternal infections during pregnancy, variations in exposure to pesticides, and seasonal patterns for air pollution. “Investigating seasonal variations in disease occurrence can provide clues about etiologically relevant factors.”

SOURCE:

Lead author Haoran Zhou, MPH, Yale University, New Haven, Conn., and colleagues published their findings online in JAMA Network Open. The study was partly supported by a grant from the American Academy for Cerebral Palsy and Developmental Medicine.

LIMITATIONS:

The study may not have fully captured all children with CP in the cohort due to the possibility of misclassification. The findings may not be generalizable beyond California. The overall increased risk associated with the season of conception was relatively small, suggesting family planning strategies may not need to change based on these findings. The exact mechanisms involving potential environmental factors need further investigation.

DISCLOSURES:

The authors reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

TOPLINE:

Cerebral palsy (CP) affects 1-4 per 1,000 live births in the United States. A new cohort study found children conceived during the winter and spring months appear to have a slightly higher risk for developing CP than those conceived during the summer. Fall months carried about the same or only slightly higher risk of CP than summer months.

METHODOLOGY:

• Researchers examined data from nearly 4.5 million live births registered in California between 2007 and 2015, exploring if the season of conception could serve as an indicator of exposure to environmental risk factors.
• For instance, infants conceived in winter months may have higher exposure to viruses like influenza. In California, agricultural pesticides are most often applied in summer months, when pregnant people would be in their first or second trimester and receive their most exposure to the fine particulates, the authors hypothesize.
• Almost 4,700 babies in the study population were diagnosed with CP. Researchers also considered the role of preterm birth as a potential mediating factor, and adjusted for sociodemographic characteristics such as maternal age, race, education, smoking during pregnancy, and body mass index.

TAKEAWAY:

• The study found that children conceived in winter and spring had a 9% (95% confidence interval, 1.01-1.19) to 10% (95% CI, 1.02-1.20) higher risk of developing CP than those conceived in the summer.
• Children conceived in January, February, or May carried a 15% higher risk, compared with babies conceived in July.
• The risk was more pronounced among mothers with low education levels or living in neighborhoods where residents have high rates of unemployment, single-parent households, multiunit households, and lower rates of high school graduates.

IN PRACTICE:

The researchers noted that possible explanations for the seasonal link to CP risk may include the prevalence of maternal infections during pregnancy, variations in exposure to pesticides, and seasonal patterns for air pollution. “Investigating seasonal variations in disease occurrence can provide clues about etiologically relevant factors.”

SOURCE:

Lead author Haoran Zhou, MPH, Yale University, New Haven, Conn., and colleagues published their findings online in JAMA Network Open. The study was partly supported by a grant from the American Academy for Cerebral Palsy and Developmental Medicine.

LIMITATIONS:

The study may not have fully captured all children with CP in the cohort due to the possibility of misclassification. The findings may not be generalizable beyond California. The overall increased risk associated with the season of conception was relatively small, suggesting family planning strategies may not need to change based on these findings. The exact mechanisms involving potential environmental factors need further investigation.

DISCLOSURES:

The authors reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Dysphagia, gastroparesis, constipation, and irritable bowel syndrome without diarrhea specifically predicted Parkinson’s disease (PD) in a new study.

Early detection of these conditions might help identify patients at risk for PD, potentially prompting preventive strategies, the researchers suggest.

The results of previous experimental studies by the team supported the Braak hypothesis, which states that idiopathic PD originates in the gut in a subset of patients. However, no previous study had investigated a broad range of gastrointestinal symptoms and syndromes that might occur prior to a PD diagnosis.

Given their preclinical work, the authors were not surprised to find that certain GI syndromes were specifically associated with PD, even when compared with Alzheimer’s disease (AD) and cerebrovascular disease (CVD), principal author Pankaj Jay Pasricha, MBBS, MD, of Mayo Clinic Arizona, Scottsdale, said in an interview. However, they were “impressed by the strength of the associations.”

“Experts have known for a very long time that constipation is a potential risk factor for PD, so this study adds to the list of GI conditions that could potentially be risk factors,” he said.

The study was published online in Gut.
 

Studies converge

To determine the incidence of GI syndromes and interventions preceding PD, the investigators performed a combined case-control and cohort study using a U.S.-based nationwide medical record network.

First, they compared 24,624 individuals with new-onset idiopathic PD with the same number of matched negative controls (NCs), as well as 19,046 people with AD and 23,942 with CVD to investigate the presence of preexisting GI conditions, which the researchers referred to as “exposures.” Overall, the mean age was about 70, and about half of those studied were women.

Eighteen conditions covering the entire GI tract were investigated. These included achalasia, dysphagia, gastroesophageal reflux disease, gastroparesis, functional dyspepsia, paralytic ileus, diarrhea, irritable bowel syndrome (IBS) with and without diarrhea, intestinal pseudo-obstruction, fecal incontinence, Crohn’s disease, ulcerative colitis, and microscopic colitis, as well as appendectomy and vagotomy.

All GI syndromes were significantly increased in the PD group, compared with NCs (odds ratio > 1). However, only preexisting dysphagia (OR, 3.58), gastroparesis (OR, 4.64), functional dyspepsia (OR, 3.39), intestinal pseudo-obstruction (OR, 3.01), diarrhea (OR, 2.85), constipation (OR, 3.32), IBS with constipation (OR, 4.11), IBS with diarrhea (OR, 4.31), IBS without diarrhea (OR, 3.53), and fecal incontinence (OR, 3.76) produced ORs that were numerically greater than the upper limit of the negative exposures.

In addition, only gastroparesis, dysphagia, IBS with constipation, IBS without diarrhea, and constipation were specific for PD, compared with the AD and CVD groups (OR > 1). After correction for false discovery rate, though, gastroparesis and constipation did not remain significantly different, compared with the AD and CVD groups.

Other preexisting GI conditions not only were significantly associated with PD but also showed strong associations with the AD and CVD groups.

To validate the case-control analyses, the team set up a complementary cohort study. Eighteen cohorts – each diagnosed with one of the GI conditions in the case-control analysis – were compared with their respective NC cohorts for the prospective risk of developing PD, AD, or CVD within 5 years.

Gastroparesis, dysphagia, IBS without diarrhea, and constipation showed specific associations with PD versus NCs, AD, and CVD in the cohort analysis. Their relative risks versus NCs were 2.43, 2.27, 1.17, and 2.38, respectively.

Functional dyspepsia, IBS with diarrhea, diarrhea, and fecal incontinence were not PD specific, but IBS with constipation and intestinal pseudo-obstruction showed PD specificity in both the case-control (OR, 4.11) and cohort analyses (RR, 1.84).

Appendectomy decreased the risk for PD in the cohort analysis (RR, 0.48), but neither inflammatory bowel disease nor vagotomy was associated with PD.

“This study is the first to establish substantial observational evidence that the clinical diagnosis of not only constipation but also dysphagia, gastroparesis, and IBS without diarrhea might specifically predict the development of PD, whereas other exposures were less specific,” the researchers wrote.

However, Dr. Pasricha said, “there is no need for alarm.” Clinicians should reassure patients that “the overall risk for developing PD is low. The overwhelming majority of patients with these GI conditions will never develop PD.”

His team will be doing experimental work on the biological mechanisms that might explain the current study’s findings. “In addition, the U.S. National Institutes of Health has issued a call for proposals to perform research in patients that could help understand these associations better,” he said.
 

Body or brain?

The Parkinson’s Foundation’s National Medical Advisor, Michael S. Okun, MD, called the study “fascinating.”

The findings “confirm many other studies showing that GI symptoms can precede a Parkinson’s disease diagnosis,” he said in an interview.

Although the study was designed to test the Braak hypothesis, “the dataset really cannot confirm or refute Braak pathology, which can only be accomplished with comparison to postmortem samples,” he added.

“The raging debate in the field of body-first versus brain-first Parkinson’s may be somewhat artificial, especially if we consider that Parkinson’s is not one disease,” Dr. Okun noted. “It will take clinical data, pathology, and the collaboration of many researchers to solve the puzzle.”

“The Foundation continues to monitor all the advancements in the ‘gut’ Parkinson field,” he said. “We do not recommend at this time changing the approach to clinical care based on this data.”

No funding or competing interests were declared. Dr. Okun declared no relevant disclosures.

A version of this article first appeared on Medscape.com.

Dysphagia, gastroparesis, constipation, and irritable bowel syndrome without diarrhea specifically predicted Parkinson’s disease (PD) in a new study.

Early detection of these conditions might help identify patients at risk for PD, potentially prompting preventive strategies, the researchers suggest.

The results of previous experimental studies by the team supported the Braak hypothesis, which states that idiopathic PD originates in the gut in a subset of patients. However, no previous study had investigated a broad range of gastrointestinal symptoms and syndromes that might occur prior to a PD diagnosis.

Given their preclinical work, the authors were not surprised to find that certain GI syndromes were specifically associated with PD, even when compared with Alzheimer’s disease (AD) and cerebrovascular disease (CVD), principal author Pankaj Jay Pasricha, MBBS, MD, of Mayo Clinic Arizona, Scottsdale, said in an interview. However, they were “impressed by the strength of the associations.”

“Experts have known for a very long time that constipation is a potential risk factor for PD, so this study adds to the list of GI conditions that could potentially be risk factors,” he said.

The study was published online in Gut.
 

Studies converge

To determine the incidence of GI syndromes and interventions preceding PD, the investigators performed a combined case-control and cohort study using a U.S.-based nationwide medical record network.

First, they compared 24,624 individuals with new-onset idiopathic PD with the same number of matched negative controls (NCs), as well as 19,046 people with AD and 23,942 with CVD to investigate the presence of preexisting GI conditions, which the researchers referred to as “exposures.” Overall, the mean age was about 70, and about half of those studied were women.

Eighteen conditions covering the entire GI tract were investigated. These included achalasia, dysphagia, gastroesophageal reflux disease, gastroparesis, functional dyspepsia, paralytic ileus, diarrhea, irritable bowel syndrome (IBS) with and without diarrhea, intestinal pseudo-obstruction, fecal incontinence, Crohn’s disease, ulcerative colitis, and microscopic colitis, as well as appendectomy and vagotomy.

All GI syndromes were significantly increased in the PD group, compared with NCs (odds ratio > 1). However, only preexisting dysphagia (OR, 3.58), gastroparesis (OR, 4.64), functional dyspepsia (OR, 3.39), intestinal pseudo-obstruction (OR, 3.01), diarrhea (OR, 2.85), constipation (OR, 3.32), IBS with constipation (OR, 4.11), IBS with diarrhea (OR, 4.31), IBS without diarrhea (OR, 3.53), and fecal incontinence (OR, 3.76) produced ORs that were numerically greater than the upper limit of the negative exposures.

In addition, only gastroparesis, dysphagia, IBS with constipation, IBS without diarrhea, and constipation were specific for PD, compared with the AD and CVD groups (OR > 1). After correction for false discovery rate, though, gastroparesis and constipation did not remain significantly different, compared with the AD and CVD groups.

Other preexisting GI conditions not only were significantly associated with PD but also showed strong associations with the AD and CVD groups.

To validate the case-control analyses, the team set up a complementary cohort study. Eighteen cohorts – each diagnosed with one of the GI conditions in the case-control analysis – were compared with their respective NC cohorts for the prospective risk of developing PD, AD, or CVD within 5 years.

Gastroparesis, dysphagia, IBS without diarrhea, and constipation showed specific associations with PD versus NCs, AD, and CVD in the cohort analysis. Their relative risks versus NCs were 2.43, 2.27, 1.17, and 2.38, respectively.

Functional dyspepsia, IBS with diarrhea, diarrhea, and fecal incontinence were not PD specific, but IBS with constipation and intestinal pseudo-obstruction showed PD specificity in both the case-control (OR, 4.11) and cohort analyses (RR, 1.84).

Appendectomy decreased the risk for PD in the cohort analysis (RR, 0.48), but neither inflammatory bowel disease nor vagotomy was associated with PD.

“This study is the first to establish substantial observational evidence that the clinical diagnosis of not only constipation but also dysphagia, gastroparesis, and IBS without diarrhea might specifically predict the development of PD, whereas other exposures were less specific,” the researchers wrote.

However, Dr. Pasricha said, “there is no need for alarm.” Clinicians should reassure patients that “the overall risk for developing PD is low. The overwhelming majority of patients with these GI conditions will never develop PD.”

His team will be doing experimental work on the biological mechanisms that might explain the current study’s findings. “In addition, the U.S. National Institutes of Health has issued a call for proposals to perform research in patients that could help understand these associations better,” he said.
 

Body or brain?

The Parkinson’s Foundation’s National Medical Advisor, Michael S. Okun, MD, called the study “fascinating.”

The findings “confirm many other studies showing that GI symptoms can precede a Parkinson’s disease diagnosis,” he said in an interview.

Although the study was designed to test the Braak hypothesis, “the dataset really cannot confirm or refute Braak pathology, which can only be accomplished with comparison to postmortem samples,” he added.

“The raging debate in the field of body-first versus brain-first Parkinson’s may be somewhat artificial, especially if we consider that Parkinson’s is not one disease,” Dr. Okun noted. “It will take clinical data, pathology, and the collaboration of many researchers to solve the puzzle.”

“The Foundation continues to monitor all the advancements in the ‘gut’ Parkinson field,” he said. “We do not recommend at this time changing the approach to clinical care based on this data.”

No funding or competing interests were declared. Dr. Okun declared no relevant disclosures.

A version of this article first appeared on Medscape.com.

Dysphagia, gastroparesis, constipation, and irritable bowel syndrome without diarrhea specifically predicted Parkinson’s disease (PD) in a new study.

Early detection of these conditions might help identify patients at risk for PD, potentially prompting preventive strategies, the researchers suggest.

The results of previous experimental studies by the team supported the Braak hypothesis, which states that idiopathic PD originates in the gut in a subset of patients. However, no previous study had investigated a broad range of gastrointestinal symptoms and syndromes that might occur prior to a PD diagnosis.

Given their preclinical work, the authors were not surprised to find that certain GI syndromes were specifically associated with PD, even when compared with Alzheimer’s disease (AD) and cerebrovascular disease (CVD), principal author Pankaj Jay Pasricha, MBBS, MD, of Mayo Clinic Arizona, Scottsdale, said in an interview. However, they were “impressed by the strength of the associations.”

“Experts have known for a very long time that constipation is a potential risk factor for PD, so this study adds to the list of GI conditions that could potentially be risk factors,” he said.

The study was published online in Gut.
 

Studies converge

To determine the incidence of GI syndromes and interventions preceding PD, the investigators performed a combined case-control and cohort study using a U.S.-based nationwide medical record network.

First, they compared 24,624 individuals with new-onset idiopathic PD with the same number of matched negative controls (NCs), as well as 19,046 people with AD and 23,942 with CVD to investigate the presence of preexisting GI conditions, which the researchers referred to as “exposures.” Overall, the mean age was about 70, and about half of those studied were women.

Eighteen conditions covering the entire GI tract were investigated. These included achalasia, dysphagia, gastroesophageal reflux disease, gastroparesis, functional dyspepsia, paralytic ileus, diarrhea, irritable bowel syndrome (IBS) with and without diarrhea, intestinal pseudo-obstruction, fecal incontinence, Crohn’s disease, ulcerative colitis, and microscopic colitis, as well as appendectomy and vagotomy.

All GI syndromes were significantly increased in the PD group, compared with NCs (odds ratio > 1). However, only preexisting dysphagia (OR, 3.58), gastroparesis (OR, 4.64), functional dyspepsia (OR, 3.39), intestinal pseudo-obstruction (OR, 3.01), diarrhea (OR, 2.85), constipation (OR, 3.32), IBS with constipation (OR, 4.11), IBS with diarrhea (OR, 4.31), IBS without diarrhea (OR, 3.53), and fecal incontinence (OR, 3.76) produced ORs that were numerically greater than the upper limit of the negative exposures.

In addition, only gastroparesis, dysphagia, IBS with constipation, IBS without diarrhea, and constipation were specific for PD, compared with the AD and CVD groups (OR > 1). After correction for false discovery rate, though, gastroparesis and constipation did not remain significantly different, compared with the AD and CVD groups.

Other preexisting GI conditions not only were significantly associated with PD but also showed strong associations with the AD and CVD groups.

To validate the case-control analyses, the team set up a complementary cohort study. Eighteen cohorts – each diagnosed with one of the GI conditions in the case-control analysis – were compared with their respective NC cohorts for the prospective risk of developing PD, AD, or CVD within 5 years.

Gastroparesis, dysphagia, IBS without diarrhea, and constipation showed specific associations with PD versus NCs, AD, and CVD in the cohort analysis. Their relative risks versus NCs were 2.43, 2.27, 1.17, and 2.38, respectively.

Functional dyspepsia, IBS with diarrhea, diarrhea, and fecal incontinence were not PD specific, but IBS with constipation and intestinal pseudo-obstruction showed PD specificity in both the case-control (OR, 4.11) and cohort analyses (RR, 1.84).

Appendectomy decreased the risk for PD in the cohort analysis (RR, 0.48), but neither inflammatory bowel disease nor vagotomy was associated with PD.

“This study is the first to establish substantial observational evidence that the clinical diagnosis of not only constipation but also dysphagia, gastroparesis, and IBS without diarrhea might specifically predict the development of PD, whereas other exposures were less specific,” the researchers wrote.

However, Dr. Pasricha said, “there is no need for alarm.” Clinicians should reassure patients that “the overall risk for developing PD is low. The overwhelming majority of patients with these GI conditions will never develop PD.”

His team will be doing experimental work on the biological mechanisms that might explain the current study’s findings. “In addition, the U.S. National Institutes of Health has issued a call for proposals to perform research in patients that could help understand these associations better,” he said.
 

Body or brain?

The Parkinson’s Foundation’s National Medical Advisor, Michael S. Okun, MD, called the study “fascinating.”

The findings “confirm many other studies showing that GI symptoms can precede a Parkinson’s disease diagnosis,” he said in an interview.

Although the study was designed to test the Braak hypothesis, “the dataset really cannot confirm or refute Braak pathology, which can only be accomplished with comparison to postmortem samples,” he added.

“The raging debate in the field of body-first versus brain-first Parkinson’s may be somewhat artificial, especially if we consider that Parkinson’s is not one disease,” Dr. Okun noted. “It will take clinical data, pathology, and the collaboration of many researchers to solve the puzzle.”

“The Foundation continues to monitor all the advancements in the ‘gut’ Parkinson field,” he said. “We do not recommend at this time changing the approach to clinical care based on this data.”

No funding or competing interests were declared. Dr. Okun declared no relevant disclosures.

A version of this article first appeared on Medscape.com.

COPENHAGEN – Giving patients with Parkinson’s disease and constipation a probiotic for 3 months improved not only their gut microbiome but also nonmotor symptoms such as sleep, fatigue, and constipation, results of a new randomized trial show.

Participants taking the probiotic also saw a reduced delay in “time to on” of treatment with levodopa, thus reducing the delay until effectiveness of the treatment, said study presenter Valentina Leta, MD, PhD, department of neurosciences, King’s College London Institute of Psychiatry, Psychology and Neuroscience.

Dr. Leta presented the findings at the International Congress of Parkinson’s Disease and Movement Disorders.

“Virtually every person with Parkinson’s might have some degree of gastrointestinal dysfunction, and virtually the entire tract might be affected, from the mouth to the rectum,” Dr. Leta told attendees of the congress.

A number of different mechanisms have been associated with this gastrointestinal dysfunction, she noted, including proinflammatory changes in the gut microbiota, so a modulatory intervention “could be a therapeutic strategy for Parkinson’s disease.”

However, “despite numerous preclinical studies showing potential beneficial effects on a variety of pathological mechanisms involved in Parkinson’s disease, the clinical evidence is limited ... to the treatment of constipation,” she explained.

The team therefore conducted a multicenter, randomized, double-blind, placebo-controlled trial, in which patients with both Parkinson’s disease and constipation, based on the Rome IV criteria, were randomly assigned to receive a probiotic or placebo for 3 months.

The probiotic used was a liquid formulation (Symprove) and contained four strains: Lacticaseibacillus rhamnosus, Enterococcus faecium, Lactobacillus acidophilus, and Lactiplantibacillus plantarum.

A total of 74 patients were randomly assigned to the two study arms. The two groups were well matched for sociodemographics, Parkinson’s disease, and constipation-related characteristics, Dr. Leta reported, and only 3 patients in each arm discontinued the study. The probiotic intervention had a “good tolerability and safety profile, with a similar number of adverse events between the two groups, and no serious adverse events.”
 

Increase in healthy bacteria

The study met its primary outcome of changes in gut microbiome at the end of the 12-week intervention, as measured on shallow shotgun sequencing.

The probiotic was associated with a “statistically significant increase of the abundance of bacteria which are known to have beneficial health related properties, such as Odoribacteraceae,” Dr. Leta said.

This bacterium is “known to be reduced in people with Parkinson’s disease,” she explained, “and is involved in the production of short-chain fatty acids, which are known to have beneficial health-related properties.”

The secondary endpoint of the study included changes in motor and nonmotor symptoms, and the probiotic was associated with a significant improvement in the “time to on” with levodopa treatment, shortening this period from an average of 31.43 minutes at baseline to 23.95 minutes at the postintervention assessment (P < .027).

There was also a significant improvement in the Non-Motor Symptoms Scale (NMSS) score between baseline and the postintervention assessment in patients given the probiotic, from 70.71 to 61.34 (P = .005).

This, Dr. Leta observed, was “driven by improvements in the sleep, fatigue, and gastrointestinal domains.”

No such significant improvements were observed in the placebo arm.
 

Probiotics ‘hot topic’ among patients

Claudia Trenkwalder, MD, full professor of neurology at University Medical Center Goettingen (Germany), said in an interview that the use of probiotics is a “hot topic in Parkinson’s disease research, especially among patients.”

Dr. Trenkwalder, who was not involved in the study, noted that Lactobacillus strains “are established in Parkinson’s disease constipation treatment, with randomized controlled trials showing a significant improvement in constipation.

“Therefore, this is a useful treatment. The question here is: Do we have additional effects that can be measured in the microbiome and in clinical symptomatology?”

The trial showed that the probiotic studied “did alter the microbiome and did improve the constipation,” said Dr. Trenkwalder; however, the current data cannot prove whether the probiotic influenced the symptoms of Parkinson’s disease because the improvement in NMSS scores “is driven by the improvement in constipation.”

This, she argued, could have resulted in better absorption of levodopa.

A dietitian in the audience agreed. She asked whether the probiotic was doing anything “besides improving constipation,” adding that the resulting increased ability to absorb levodopa is also “going to help your sleep.”
 

Beyond constipation?

Dr. Leta replied that “we can assume that there is a link between the reduction in the ‘time to on’ and the improvement in constipation. We are doing some analyses in terms of levodopa pharmacokinetics to really understand the mechanisms behind this result.”

Although the improvement in constipation is “one of the possible hypotheses for the improvement in ‘time to on,’” she continued, “there is a more speculative one” in which the probiotics are modulating inflammatory parameters that could contribute to the improvement in sleep.

Veronica Bruno, MD, MPH, assistant professor in the department of clinical neurosciences at the University of Calgary (Alta.), commented in a press release that there has been “increasing interest” in examining the relationship between gut dysbiosis and the “gut-brain axis” in Parkinson’s disease.

The current study “stands out as a significant contribution to this area of study,” she said.

“While the implications of the observed changes in gut microbiota remain a captivating realm for further investigation, a particularly noteworthy finding revolves around the reduction in the ‘time to on’ observed within the active treatment group.”

Dr. Bruno said that shortening of the time to on “holds promise for substantial enhancements in patients’ lives” by reducing “difficult ‘off’ intervals and enhancing overall well-being.”

The study was funded by the UK National Institute for Health Research Mental Health Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust, and King’s College London. No relevant financial relationships were declared.

A version of this article first appeared on Medscape.com.

COPENHAGEN – Giving patients with Parkinson’s disease and constipation a probiotic for 3 months improved not only their gut microbiome but also nonmotor symptoms such as sleep, fatigue, and constipation, results of a new randomized trial show.

Participants taking the probiotic also saw a reduced delay in “time to on” of treatment with levodopa, thus reducing the delay until effectiveness of the treatment, said study presenter Valentina Leta, MD, PhD, department of neurosciences, King’s College London Institute of Psychiatry, Psychology and Neuroscience.

Dr. Leta presented the findings at the International Congress of Parkinson’s Disease and Movement Disorders.

“Virtually every person with Parkinson’s might have some degree of gastrointestinal dysfunction, and virtually the entire tract might be affected, from the mouth to the rectum,” Dr. Leta told attendees of the congress.

A number of different mechanisms have been associated with this gastrointestinal dysfunction, she noted, including proinflammatory changes in the gut microbiota, so a modulatory intervention “could be a therapeutic strategy for Parkinson’s disease.”

However, “despite numerous preclinical studies showing potential beneficial effects on a variety of pathological mechanisms involved in Parkinson’s disease, the clinical evidence is limited ... to the treatment of constipation,” she explained.

The team therefore conducted a multicenter, randomized, double-blind, placebo-controlled trial, in which patients with both Parkinson’s disease and constipation, based on the Rome IV criteria, were randomly assigned to receive a probiotic or placebo for 3 months.

The probiotic used was a liquid formulation (Symprove) and contained four strains: Lacticaseibacillus rhamnosus, Enterococcus faecium, Lactobacillus acidophilus, and Lactiplantibacillus plantarum.

A total of 74 patients were randomly assigned to the two study arms. The two groups were well matched for sociodemographics, Parkinson’s disease, and constipation-related characteristics, Dr. Leta reported, and only 3 patients in each arm discontinued the study. The probiotic intervention had a “good tolerability and safety profile, with a similar number of adverse events between the two groups, and no serious adverse events.”
 

Increase in healthy bacteria

The study met its primary outcome of changes in gut microbiome at the end of the 12-week intervention, as measured on shallow shotgun sequencing.

The probiotic was associated with a “statistically significant increase of the abundance of bacteria which are known to have beneficial health related properties, such as Odoribacteraceae,” Dr. Leta said.

This bacterium is “known to be reduced in people with Parkinson’s disease,” she explained, “and is involved in the production of short-chain fatty acids, which are known to have beneficial health-related properties.”

The secondary endpoint of the study included changes in motor and nonmotor symptoms, and the probiotic was associated with a significant improvement in the “time to on” with levodopa treatment, shortening this period from an average of 31.43 minutes at baseline to 23.95 minutes at the postintervention assessment (P < .027).

There was also a significant improvement in the Non-Motor Symptoms Scale (NMSS) score between baseline and the postintervention assessment in patients given the probiotic, from 70.71 to 61.34 (P = .005).

This, Dr. Leta observed, was “driven by improvements in the sleep, fatigue, and gastrointestinal domains.”

No such significant improvements were observed in the placebo arm.
 

Probiotics ‘hot topic’ among patients

Claudia Trenkwalder, MD, full professor of neurology at University Medical Center Goettingen (Germany), said in an interview that the use of probiotics is a “hot topic in Parkinson’s disease research, especially among patients.”

Dr. Trenkwalder, who was not involved in the study, noted that Lactobacillus strains “are established in Parkinson’s disease constipation treatment, with randomized controlled trials showing a significant improvement in constipation.

“Therefore, this is a useful treatment. The question here is: Do we have additional effects that can be measured in the microbiome and in clinical symptomatology?”

The trial showed that the probiotic studied “did alter the microbiome and did improve the constipation,” said Dr. Trenkwalder; however, the current data cannot prove whether the probiotic influenced the symptoms of Parkinson’s disease because the improvement in NMSS scores “is driven by the improvement in constipation.”

This, she argued, could have resulted in better absorption of levodopa.

A dietitian in the audience agreed. She asked whether the probiotic was doing anything “besides improving constipation,” adding that the resulting increased ability to absorb levodopa is also “going to help your sleep.”
 

Beyond constipation?

Dr. Leta replied that “we can assume that there is a link between the reduction in the ‘time to on’ and the improvement in constipation. We are doing some analyses in terms of levodopa pharmacokinetics to really understand the mechanisms behind this result.”

Although the improvement in constipation is “one of the possible hypotheses for the improvement in ‘time to on,’” she continued, “there is a more speculative one” in which the probiotics are modulating inflammatory parameters that could contribute to the improvement in sleep.

Veronica Bruno, MD, MPH, assistant professor in the department of clinical neurosciences at the University of Calgary (Alta.), commented in a press release that there has been “increasing interest” in examining the relationship between gut dysbiosis and the “gut-brain axis” in Parkinson’s disease.

The current study “stands out as a significant contribution to this area of study,” she said.

“While the implications of the observed changes in gut microbiota remain a captivating realm for further investigation, a particularly noteworthy finding revolves around the reduction in the ‘time to on’ observed within the active treatment group.”

Dr. Bruno said that shortening of the time to on “holds promise for substantial enhancements in patients’ lives” by reducing “difficult ‘off’ intervals and enhancing overall well-being.”

The study was funded by the UK National Institute for Health Research Mental Health Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust, and King’s College London. No relevant financial relationships were declared.

A version of this article first appeared on Medscape.com.

COPENHAGEN – Giving patients with Parkinson’s disease and constipation a probiotic for 3 months improved not only their gut microbiome but also nonmotor symptoms such as sleep, fatigue, and constipation, results of a new randomized trial show.

Participants taking the probiotic also saw a reduced delay in “time to on” of treatment with levodopa, thus reducing the delay until effectiveness of the treatment, said study presenter Valentina Leta, MD, PhD, department of neurosciences, King’s College London Institute of Psychiatry, Psychology and Neuroscience.

Dr. Leta presented the findings at the International Congress of Parkinson’s Disease and Movement Disorders.

“Virtually every person with Parkinson’s might have some degree of gastrointestinal dysfunction, and virtually the entire tract might be affected, from the mouth to the rectum,” Dr. Leta told attendees of the congress.

A number of different mechanisms have been associated with this gastrointestinal dysfunction, she noted, including proinflammatory changes in the gut microbiota, so a modulatory intervention “could be a therapeutic strategy for Parkinson’s disease.”

However, “despite numerous preclinical studies showing potential beneficial effects on a variety of pathological mechanisms involved in Parkinson’s disease, the clinical evidence is limited ... to the treatment of constipation,” she explained.

The team therefore conducted a multicenter, randomized, double-blind, placebo-controlled trial, in which patients with both Parkinson’s disease and constipation, based on the Rome IV criteria, were randomly assigned to receive a probiotic or placebo for 3 months.

The probiotic used was a liquid formulation (Symprove) and contained four strains: Lacticaseibacillus rhamnosus, Enterococcus faecium, Lactobacillus acidophilus, and Lactiplantibacillus plantarum.

A total of 74 patients were randomly assigned to the two study arms. The two groups were well matched for sociodemographics, Parkinson’s disease, and constipation-related characteristics, Dr. Leta reported, and only 3 patients in each arm discontinued the study. The probiotic intervention had a “good tolerability and safety profile, with a similar number of adverse events between the two groups, and no serious adverse events.”
 

Increase in healthy bacteria

The study met its primary outcome of changes in gut microbiome at the end of the 12-week intervention, as measured on shallow shotgun sequencing.

The probiotic was associated with a “statistically significant increase of the abundance of bacteria which are known to have beneficial health related properties, such as Odoribacteraceae,” Dr. Leta said.

This bacterium is “known to be reduced in people with Parkinson’s disease,” she explained, “and is involved in the production of short-chain fatty acids, which are known to have beneficial health-related properties.”

The secondary endpoint of the study included changes in motor and nonmotor symptoms, and the probiotic was associated with a significant improvement in the “time to on” with levodopa treatment, shortening this period from an average of 31.43 minutes at baseline to 23.95 minutes at the postintervention assessment (P < .027).

There was also a significant improvement in the Non-Motor Symptoms Scale (NMSS) score between baseline and the postintervention assessment in patients given the probiotic, from 70.71 to 61.34 (P = .005).

This, Dr. Leta observed, was “driven by improvements in the sleep, fatigue, and gastrointestinal domains.”

No such significant improvements were observed in the placebo arm.
 

Probiotics ‘hot topic’ among patients

Claudia Trenkwalder, MD, full professor of neurology at University Medical Center Goettingen (Germany), said in an interview that the use of probiotics is a “hot topic in Parkinson’s disease research, especially among patients.”

Dr. Trenkwalder, who was not involved in the study, noted that Lactobacillus strains “are established in Parkinson’s disease constipation treatment, with randomized controlled trials showing a significant improvement in constipation.

“Therefore, this is a useful treatment. The question here is: Do we have additional effects that can be measured in the microbiome and in clinical symptomatology?”

The trial showed that the probiotic studied “did alter the microbiome and did improve the constipation,” said Dr. Trenkwalder; however, the current data cannot prove whether the probiotic influenced the symptoms of Parkinson’s disease because the improvement in NMSS scores “is driven by the improvement in constipation.”

This, she argued, could have resulted in better absorption of levodopa.

A dietitian in the audience agreed. She asked whether the probiotic was doing anything “besides improving constipation,” adding that the resulting increased ability to absorb levodopa is also “going to help your sleep.”
 

Beyond constipation?

Dr. Leta replied that “we can assume that there is a link between the reduction in the ‘time to on’ and the improvement in constipation. We are doing some analyses in terms of levodopa pharmacokinetics to really understand the mechanisms behind this result.”

Although the improvement in constipation is “one of the possible hypotheses for the improvement in ‘time to on,’” she continued, “there is a more speculative one” in which the probiotics are modulating inflammatory parameters that could contribute to the improvement in sleep.

Veronica Bruno, MD, MPH, assistant professor in the department of clinical neurosciences at the University of Calgary (Alta.), commented in a press release that there has been “increasing interest” in examining the relationship between gut dysbiosis and the “gut-brain axis” in Parkinson’s disease.

The current study “stands out as a significant contribution to this area of study,” she said.

“While the implications of the observed changes in gut microbiota remain a captivating realm for further investigation, a particularly noteworthy finding revolves around the reduction in the ‘time to on’ observed within the active treatment group.”

Dr. Bruno said that shortening of the time to on “holds promise for substantial enhancements in patients’ lives” by reducing “difficult ‘off’ intervals and enhancing overall well-being.”

The study was funded by the UK National Institute for Health Research Mental Health Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust, and King’s College London. No relevant financial relationships were declared.

A version of this article first appeared on Medscape.com.

In 2017, Sanofi Genzyme launched a phase 2 clinical trial of a drug designed to target a specific genetic mutation in some patients with Parkinson’s disease. Researchers hoped the drug would slow or even stop disease progression.

Like many before it, the trial yielded disappointing results and the company shut it down in 2021. It was the latest in a string of unsuccessful clinical trials testing disease-modifying Parkinson’s disease drugs.

Although it failed, the Sanofi Genzyme study was different: It was the first to enroll patients with Parkinson’s disease who had a specific genotype and marked the earliest days of precision medicine and gene-specific drug development for the disease.

Once thought to play only a small role in a small number of patients with Parkinson’s disease, a growing body of work has prompted researchers and drug developers to take a longer look at how genetics influence Parkinson’s disease risk and progression.

“We’re about to enter this era of precision medicine for Parkinson’s disease, which makes genetic testing important,” said James Beck, PhD, senior vice president and chief scientific officer for the Parkinson’s Foundation.

“A number of companies have clinical trials or are in preparation for clinical trials to test some specific therapies that would depend upon people having a specific genetic mutation,” he said.

Today, at least four clinical trials of drugs that target specific Parkinson’s disease-related gene variants on LRRK2 and GBA are under way, and more are in the pipeline. Whether these drugs will be effective at modifying the course of the disease remains to be seen. First, the trials must enroll enough patients. And therein lies the challenge: Genetic testing isn’t part of routine Parkinson’s disease care and isn’t covered by most insurance policies. Most patients don’t know their genotype.

It’s a significant roadblock to the future of a precision medicine approach that is based on a patient’s individual genotype, which some experts argue offers the best shot at slowing disease progression.

“To enroll in clinical trials for precision drugs people with Parkinson’s disease have to be aware of their genetic status,” said Roy N. Alcalay, MD, chief of the movement disorders division at Tel Aviv Medical Center in Israel and part-time associate professor at Columbia University in New York. “How can a person with Parkinson’s and a LRRK2 mutation join a precision medicine trial for LRRK2 if she does not know she is a LRRK2 carrier?”
 

Free genetic testing

Previous studies have shown that some genetic variants increase the risk for Parkinson’s disease after exposure to environmental factors such as pesticides. Research has also shown that a patient’s genotype can predict survival time and that certain medications may prove more effective at slowing disease progression in patients with specific genotypes. All of this points to a significant role for genetics in a disorder that is rapidly increasing.

This makes expanding patient access to genetic testing even more important, Dr. Alcalay said, noting that it’s equally important that patients are informed of their genotype, something that doesn’t usually happen in blinded clinical trials.

To that end, Dr. Alcalay hopes a national genetics study he is leading will address access and need-to-know issues. PD GENEration, a project launched in 2019 by the Parkinson’s Foundation, offers patients free genetic testing for seven clinically relevant Parkinson’s disease-related genes.

Testing is done at home or in a nearby clinic and the results are shared with patients during a free genetic counseling session and with site investigators. Patient samples are stored in a genetic data bank that is open to researchers around the world.

“We surveyed clinical trialists in the Parkinson’s disease field prior to initiation of PD GENEration and estimated that over 90% of people with Parkinson’s disease prior to the effort were not aware of their genetic status,” Dr. Alcalay said.

“I think precision medicine in Parkinson’s disease will not happen without PD GENEration or similar efforts.”
 

‘Overwhelming’ patient interest

Participants in the study are screened for variants in seven genes known to be involved in Parkinson’s disease risk: GBA, LRRK2, PRKN, PINK1, SNCA, PARK7, and VPS35.

In less than 3 years, the study has already produced what is thought to be the largest genetic data bank of sequenced sets of Parkinson’s disease-risk genes made accessible to patients. Since the end of 2020, the first year of patient enrollment, the number of participants has increased from 676 to 10,515 and the number of participating clinical sites rose from 12 to 101.

The foundation has spent nearly $20 million on the project so far and plans to spend another $10 million to reach a goal of 15,000 patients. The study, which is funded by private donors, is so successful that the foundation has had to scale back enrollment.

“When we were at a peak, we had over 700 participants enrolling each month,” Dr. Beck said. Beginning in April, the program capped new sign-ups to 200 patients per month and created a waiting list for future enrollment. The waiting list is hundreds of patients long.

“The participants’ response to enroll in PD GENEration demonstrates there is an overwhelming interest by people with Parkinson’s disease to learn more about their genetic risk factors,” Dr. Alcalay said.
 

A research driver

Nearly 60% of participants enrolled so far are male and close to 80% are White. The average age is 69 years and 44% were diagnosed in the past 5 years. Close to 75% had never participated in a clinical trial.

Nearly 13% have tested positive for mutations on at least one of the seven target genes. Previous studies had suggested genetics were involved in only about 10% of cases.

The majority of those with positive results had early-onset Parkinson’s disease, high-risk ancestry, or a first-degree relative with the disease. However, 9% of people who tested positive weren’t in any of those categories.

Genetic information collected by the project is shared with the Global Parkinson’s Genetics Program (GP2), a resource program of the Aligning Science Across Parkinson’s initiative that is focused on the disease’s genetic architecture. Researchers around the world have access to GP2 data to study known gene variants and identify new ones.

PD GENEration participants can choose to be notified if they are carriers of gene variants discovered in the future.

“All DNA samples shared by participants are undergoing research-grade testing,” Dr. Beck said. “Not only do we want to be able to inform people with Parkinson’s disease about their genetic status, but we also want to be able to use this precious resource to further drive research into the genetics of Parkinson’s disease.”
 

Early success

Patient recruitment has long been one of the biggest challenges to any clinical trial’s success. Research suggests that 90% of all clinical trials fail to reach recruitment milestones in their allotted time frame and two-thirds of multicenter trials fold because too few patients sign up. Data from the Parkinson’s Foundation show that only about 1% of all patients with Parkinson’s disease participate in clinical trials.

Increasing those numbers is the primary goal of PD GENEration, Dr. Beck said. And there’s evidence it’s already paying off.

Earlier this year, one of the program’s participating clinical sites, Intermountain Health, in Salt Lake City, Utah, joined a phase 2 clinical trial of an experimental drug that targets a mutation on the GBA1 gene.

“One of the reasons we were able to participate was when we got the call about joining, we were able to say that we had patients with that specific gene mutation, and we could only say that because the patients had been genotyped through PD GENEration,” said Kathleen E. McKee, MD, director of movement disorders, associate medical director of neurosciences research, and PD GENEration principal investigator at Intermountain Health.

Since 2021, Dr. McKee has enrolled hundreds of patients in the foundation’s gene study and hopes to enroll even more. Few patients turn down the opportunity to participate, she added. Knowing their genotype has proven empowering for her patients, most of whom could not afford genetic testing on their own.

“Previously I would tell patients this is not going to change your immediate management,” Dr. McKee said. “Now I tell my patients that these trials are out there, it may actually change how I treat you and what I recommend.”
 

A version of this article appeared on Medscape.com.

In 2017, Sanofi Genzyme launched a phase 2 clinical trial of a drug designed to target a specific genetic mutation in some patients with Parkinson’s disease. Researchers hoped the drug would slow or even stop disease progression.

Like many before it, the trial yielded disappointing results and the company shut it down in 2021. It was the latest in a string of unsuccessful clinical trials testing disease-modifying Parkinson’s disease drugs.

Although it failed, the Sanofi Genzyme study was different: It was the first to enroll patients with Parkinson’s disease who had a specific genotype and marked the earliest days of precision medicine and gene-specific drug development for the disease.

Once thought to play only a small role in a small number of patients with Parkinson’s disease, a growing body of work has prompted researchers and drug developers to take a longer look at how genetics influence Parkinson’s disease risk and progression.

“We’re about to enter this era of precision medicine for Parkinson’s disease, which makes genetic testing important,” said James Beck, PhD, senior vice president and chief scientific officer for the Parkinson’s Foundation.

“A number of companies have clinical trials or are in preparation for clinical trials to test some specific therapies that would depend upon people having a specific genetic mutation,” he said.

Today, at least four clinical trials of drugs that target specific Parkinson’s disease-related gene variants on LRRK2 and GBA are under way, and more are in the pipeline. Whether these drugs will be effective at modifying the course of the disease remains to be seen. First, the trials must enroll enough patients. And therein lies the challenge: Genetic testing isn’t part of routine Parkinson’s disease care and isn’t covered by most insurance policies. Most patients don’t know their genotype.

It’s a significant roadblock to the future of a precision medicine approach that is based on a patient’s individual genotype, which some experts argue offers the best shot at slowing disease progression.

“To enroll in clinical trials for precision drugs people with Parkinson’s disease have to be aware of their genetic status,” said Roy N. Alcalay, MD, chief of the movement disorders division at Tel Aviv Medical Center in Israel and part-time associate professor at Columbia University in New York. “How can a person with Parkinson’s and a LRRK2 mutation join a precision medicine trial for LRRK2 if she does not know she is a LRRK2 carrier?”
 

Free genetic testing

Previous studies have shown that some genetic variants increase the risk for Parkinson’s disease after exposure to environmental factors such as pesticides. Research has also shown that a patient’s genotype can predict survival time and that certain medications may prove more effective at slowing disease progression in patients with specific genotypes. All of this points to a significant role for genetics in a disorder that is rapidly increasing.

This makes expanding patient access to genetic testing even more important, Dr. Alcalay said, noting that it’s equally important that patients are informed of their genotype, something that doesn’t usually happen in blinded clinical trials.

To that end, Dr. Alcalay hopes a national genetics study he is leading will address access and need-to-know issues. PD GENEration, a project launched in 2019 by the Parkinson’s Foundation, offers patients free genetic testing for seven clinically relevant Parkinson’s disease-related genes.

Testing is done at home or in a nearby clinic and the results are shared with patients during a free genetic counseling session and with site investigators. Patient samples are stored in a genetic data bank that is open to researchers around the world.

“We surveyed clinical trialists in the Parkinson’s disease field prior to initiation of PD GENEration and estimated that over 90% of people with Parkinson’s disease prior to the effort were not aware of their genetic status,” Dr. Alcalay said.

“I think precision medicine in Parkinson’s disease will not happen without PD GENEration or similar efforts.”
 

‘Overwhelming’ patient interest

Participants in the study are screened for variants in seven genes known to be involved in Parkinson’s disease risk: GBA, LRRK2, PRKN, PINK1, SNCA, PARK7, and VPS35.

In less than 3 years, the study has already produced what is thought to be the largest genetic data bank of sequenced sets of Parkinson’s disease-risk genes made accessible to patients. Since the end of 2020, the first year of patient enrollment, the number of participants has increased from 676 to 10,515 and the number of participating clinical sites rose from 12 to 101.

The foundation has spent nearly $20 million on the project so far and plans to spend another $10 million to reach a goal of 15,000 patients. The study, which is funded by private donors, is so successful that the foundation has had to scale back enrollment.

“When we were at a peak, we had over 700 participants enrolling each month,” Dr. Beck said. Beginning in April, the program capped new sign-ups to 200 patients per month and created a waiting list for future enrollment. The waiting list is hundreds of patients long.

“The participants’ response to enroll in PD GENEration demonstrates there is an overwhelming interest by people with Parkinson’s disease to learn more about their genetic risk factors,” Dr. Alcalay said.
 

A research driver

Nearly 60% of participants enrolled so far are male and close to 80% are White. The average age is 69 years and 44% were diagnosed in the past 5 years. Close to 75% had never participated in a clinical trial.

Nearly 13% have tested positive for mutations on at least one of the seven target genes. Previous studies had suggested genetics were involved in only about 10% of cases.

The majority of those with positive results had early-onset Parkinson’s disease, high-risk ancestry, or a first-degree relative with the disease. However, 9% of people who tested positive weren’t in any of those categories.

Genetic information collected by the project is shared with the Global Parkinson’s Genetics Program (GP2), a resource program of the Aligning Science Across Parkinson’s initiative that is focused on the disease’s genetic architecture. Researchers around the world have access to GP2 data to study known gene variants and identify new ones.

PD GENEration participants can choose to be notified if they are carriers of gene variants discovered in the future.

“All DNA samples shared by participants are undergoing research-grade testing,” Dr. Beck said. “Not only do we want to be able to inform people with Parkinson’s disease about their genetic status, but we also want to be able to use this precious resource to further drive research into the genetics of Parkinson’s disease.”
 

Early success

Patient recruitment has long been one of the biggest challenges to any clinical trial’s success. Research suggests that 90% of all clinical trials fail to reach recruitment milestones in their allotted time frame and two-thirds of multicenter trials fold because too few patients sign up. Data from the Parkinson’s Foundation show that only about 1% of all patients with Parkinson’s disease participate in clinical trials.

Increasing those numbers is the primary goal of PD GENEration, Dr. Beck said. And there’s evidence it’s already paying off.

Earlier this year, one of the program’s participating clinical sites, Intermountain Health, in Salt Lake City, Utah, joined a phase 2 clinical trial of an experimental drug that targets a mutation on the GBA1 gene.

“One of the reasons we were able to participate was when we got the call about joining, we were able to say that we had patients with that specific gene mutation, and we could only say that because the patients had been genotyped through PD GENEration,” said Kathleen E. McKee, MD, director of movement disorders, associate medical director of neurosciences research, and PD GENEration principal investigator at Intermountain Health.

Since 2021, Dr. McKee has enrolled hundreds of patients in the foundation’s gene study and hopes to enroll even more. Few patients turn down the opportunity to participate, she added. Knowing their genotype has proven empowering for her patients, most of whom could not afford genetic testing on their own.

“Previously I would tell patients this is not going to change your immediate management,” Dr. McKee said. “Now I tell my patients that these trials are out there, it may actually change how I treat you and what I recommend.”
 

A version of this article appeared on Medscape.com.

In 2017, Sanofi Genzyme launched a phase 2 clinical trial of a drug designed to target a specific genetic mutation in some patients with Parkinson’s disease. Researchers hoped the drug would slow or even stop disease progression.

Like many before it, the trial yielded disappointing results and the company shut it down in 2021. It was the latest in a string of unsuccessful clinical trials testing disease-modifying Parkinson’s disease drugs.

Although it failed, the Sanofi Genzyme study was different: It was the first to enroll patients with Parkinson’s disease who had a specific genotype and marked the earliest days of precision medicine and gene-specific drug development for the disease.

Once thought to play only a small role in a small number of patients with Parkinson’s disease, a growing body of work has prompted researchers and drug developers to take a longer look at how genetics influence Parkinson’s disease risk and progression.

“We’re about to enter this era of precision medicine for Parkinson’s disease, which makes genetic testing important,” said James Beck, PhD, senior vice president and chief scientific officer for the Parkinson’s Foundation.

“A number of companies have clinical trials or are in preparation for clinical trials to test some specific therapies that would depend upon people having a specific genetic mutation,” he said.

Today, at least four clinical trials of drugs that target specific Parkinson’s disease-related gene variants on LRRK2 and GBA are under way, and more are in the pipeline. Whether these drugs will be effective at modifying the course of the disease remains to be seen. First, the trials must enroll enough patients. And therein lies the challenge: Genetic testing isn’t part of routine Parkinson’s disease care and isn’t covered by most insurance policies. Most patients don’t know their genotype.

It’s a significant roadblock to the future of a precision medicine approach that is based on a patient’s individual genotype, which some experts argue offers the best shot at slowing disease progression.

“To enroll in clinical trials for precision drugs people with Parkinson’s disease have to be aware of their genetic status,” said Roy N. Alcalay, MD, chief of the movement disorders division at Tel Aviv Medical Center in Israel and part-time associate professor at Columbia University in New York. “How can a person with Parkinson’s and a LRRK2 mutation join a precision medicine trial for LRRK2 if she does not know she is a LRRK2 carrier?”
 

Free genetic testing

Previous studies have shown that some genetic variants increase the risk for Parkinson’s disease after exposure to environmental factors such as pesticides. Research has also shown that a patient’s genotype can predict survival time and that certain medications may prove more effective at slowing disease progression in patients with specific genotypes. All of this points to a significant role for genetics in a disorder that is rapidly increasing.

This makes expanding patient access to genetic testing even more important, Dr. Alcalay said, noting that it’s equally important that patients are informed of their genotype, something that doesn’t usually happen in blinded clinical trials.

To that end, Dr. Alcalay hopes a national genetics study he is leading will address access and need-to-know issues. PD GENEration, a project launched in 2019 by the Parkinson’s Foundation, offers patients free genetic testing for seven clinically relevant Parkinson’s disease-related genes.

Testing is done at home or in a nearby clinic and the results are shared with patients during a free genetic counseling session and with site investigators. Patient samples are stored in a genetic data bank that is open to researchers around the world.

“We surveyed clinical trialists in the Parkinson’s disease field prior to initiation of PD GENEration and estimated that over 90% of people with Parkinson’s disease prior to the effort were not aware of their genetic status,” Dr. Alcalay said.

“I think precision medicine in Parkinson’s disease will not happen without PD GENEration or similar efforts.”
 

‘Overwhelming’ patient interest

Participants in the study are screened for variants in seven genes known to be involved in Parkinson’s disease risk: GBA, LRRK2, PRKN, PINK1, SNCA, PARK7, and VPS35.

In less than 3 years, the study has already produced what is thought to be the largest genetic data bank of sequenced sets of Parkinson’s disease-risk genes made accessible to patients. Since the end of 2020, the first year of patient enrollment, the number of participants has increased from 676 to 10,515 and the number of participating clinical sites rose from 12 to 101.

The foundation has spent nearly $20 million on the project so far and plans to spend another $10 million to reach a goal of 15,000 patients. The study, which is funded by private donors, is so successful that the foundation has had to scale back enrollment.

“When we were at a peak, we had over 700 participants enrolling each month,” Dr. Beck said. Beginning in April, the program capped new sign-ups to 200 patients per month and created a waiting list for future enrollment. The waiting list is hundreds of patients long.

“The participants’ response to enroll in PD GENEration demonstrates there is an overwhelming interest by people with Parkinson’s disease to learn more about their genetic risk factors,” Dr. Alcalay said.
 

A research driver

Nearly 60% of participants enrolled so far are male and close to 80% are White. The average age is 69 years and 44% were diagnosed in the past 5 years. Close to 75% had never participated in a clinical trial.

Nearly 13% have tested positive for mutations on at least one of the seven target genes. Previous studies had suggested genetics were involved in only about 10% of cases.

The majority of those with positive results had early-onset Parkinson’s disease, high-risk ancestry, or a first-degree relative with the disease. However, 9% of people who tested positive weren’t in any of those categories.

Genetic information collected by the project is shared with the Global Parkinson’s Genetics Program (GP2), a resource program of the Aligning Science Across Parkinson’s initiative that is focused on the disease’s genetic architecture. Researchers around the world have access to GP2 data to study known gene variants and identify new ones.

PD GENEration participants can choose to be notified if they are carriers of gene variants discovered in the future.

“All DNA samples shared by participants are undergoing research-grade testing,” Dr. Beck said. “Not only do we want to be able to inform people with Parkinson’s disease about their genetic status, but we also want to be able to use this precious resource to further drive research into the genetics of Parkinson’s disease.”
 

Early success

Patient recruitment has long been one of the biggest challenges to any clinical trial’s success. Research suggests that 90% of all clinical trials fail to reach recruitment milestones in their allotted time frame and two-thirds of multicenter trials fold because too few patients sign up. Data from the Parkinson’s Foundation show that only about 1% of all patients with Parkinson’s disease participate in clinical trials.

Increasing those numbers is the primary goal of PD GENEration, Dr. Beck said. And there’s evidence it’s already paying off.

Earlier this year, one of the program’s participating clinical sites, Intermountain Health, in Salt Lake City, Utah, joined a phase 2 clinical trial of an experimental drug that targets a mutation on the GBA1 gene.

“One of the reasons we were able to participate was when we got the call about joining, we were able to say that we had patients with that specific gene mutation, and we could only say that because the patients had been genotyped through PD GENEration,” said Kathleen E. McKee, MD, director of movement disorders, associate medical director of neurosciences research, and PD GENEration principal investigator at Intermountain Health.

Since 2021, Dr. McKee has enrolled hundreds of patients in the foundation’s gene study and hopes to enroll even more. Few patients turn down the opportunity to participate, she added. Knowing their genotype has proven empowering for her patients, most of whom could not afford genetic testing on their own.

“Previously I would tell patients this is not going to change your immediate management,” Dr. McKee said. “Now I tell my patients that these trials are out there, it may actually change how I treat you and what I recommend.”
 

A version of this article appeared on Medscape.com.

Ropinirole, a drug used for Parkinson’s disease (PD), shows promise in slowing the progression of amyotrophic lateral sclerosis (ALS), early research suggests. However, at least one expert believes the study has “significant flaws.”
 

Investigators randomly assigned 20 individuals with sporadic ALS to receive either ropinirole or placebo for 24 weeks. During the double-blind period, there was no difference between the groups in terms of decline in functional status.

However, during a further open-label extension period, the ropinirole group showed significant suppression of functional decline and an average of an additional 7 months of progression-free survival.

The researchers were able to predict clinical responsiveness to ropinirole in vitro by analyzing motor neurons derived from participants’ stem cells.

“We found that ropinirole is safe and tolerable for ALS patients and shows therapeutic promise at helping them sustain daily activity and muscle strength,” first author Satoru Morimoto, MD, of the department of physiology, Keio University School of Medicine, Tokyo, said in a news release.

The study was published online in Cell Stem Cell.
 

Feasibility study

“ALS is totally incurable and it’s a very difficult disease to treat,” senior author Hideyuki Okano, MD, PhD, professor, department of physiology, Keio University, said in the news release.

Preclinical animal models have “limited translational potential” for identifying drug candidates, but induced pluripotent stem cell (iPSC)–derived motor neurons (MNs) from ALS patients can “overcome these limitations for drug screening,” the authors write.

“We previously identified ropinirole [a dopamine D2 receptor agonist] as a potential anti-ALS drug in vitro by iPSC drug discovery,” Dr. Okano said.

The current trial was a randomized, placebo-controlled phase 1/2a feasibility trial that evaluated the safety, tolerability, and efficacy of ropinirole in patients with ALS, using several parameters:

• The revised ALS functional rating scale (ALSFRS-R) score.
• Composite functional endpoints.
• Event-free survival.
• Time to ≤ 50% forced vital capacity (FVC).

The trial consisted of a 12-week run-in period, a 24-week double-blind period, an open-label extension period that lasted from 4 to 24 weeks, and a 4-week follow-up period after administration.

Thirteen patients were assigned to receive ropinirole (23.1% women; mean age, 65.2 ± 12.6 years; 7.7% with clinically definite and 76.9% with clinically probable ALS); seven were assigned to receive placebo (57.1% women; mean age, 66.3 ± 7.5 years; 14.3% with clinically definite and 85.7% with clinically probable ALS).

Of the treatment group, 30.8% had a bulbar onset lesion vs. 57.1% in the placebo group. At baseline, the mean FVC was 94.4% ± 14.9 and 81.5% ± 23.2 in the ropinirole and placebo groups, respectively. The mean body mass index (BMI) was 22.91 ± 3.82 and 19.69 ± 2.63, respectively.

Of the participants,12 in the ropinirole and six in the control group completed the full 24-week treatment protocol; 12 in the ropinirole and five in the placebo group completed the open-label extension (participants who had received placebo were switched to the active drug).

However only seven participants in the ropinirole group and one participant in the placebo group completed the full 1-year trial.
 

‘Striking correlation’

“During the double-blind period, muscle strength and daily activity were maintained, but a decline in the ALSFRS-R … was not different from that in the placebo group,” the researchers write.

In the open-label extension period, the ropinirole group showed “significant suppression of ALSFRS-R decline,” with an ALSFRS-R score change of only 7.75 (95% confidence interval, 10.66-4.63) for the treatment group vs. 17.51 (95% CI, 22.46-12.56) for the placebo group.

The researchers used the assessment of function and survival (CAFS) score, which adjusts the ALSFRS-R score against mortality, to see whether functional benefits translated into improved survival.

The score “favored ropinirole” in the open-extension period and the entire treatment period but not in the double-blind period.

164031_graphic_web.jpg

Significant flaws

Commenting for this article, Carmel Armon, MD, MHS, professor of neurology, Loma Linda (Calif.) University, said the study “falls short of being a credible 1/2a clinical trial.”

Although the “intentions were good and the design not unusual,” the two groups were not “balanced on risk factors for faster progressing disease.” Rather, the placebo group was “tilted towards faster progressing disease” because there were more clinically definite and probable ALS patients in the placebo group than the treatment group, and there were more patients with bulbar onset.

Participants in the placebo group also had shorter median disease duration, lower BMI, and lower FVC, noted Dr. Armon, who was not involved with the study.

And only 1 in 7 control patients completed the open-label extension, compared with 7 of 13 patients in the intervention group.

“With these limitations, I would be disinclined to rely on the findings to justify a larger clinical trial,” Dr. Armon concluded.

The trial was sponsored by K Pharma. The study drug, active drugs, and placebo were supplied free of charge by GlaxoSmithKline K.K. Dr. Okano received grants from JSPS and AMED and grants and personal fees from K Pharma during the conduct of the study and personal fees from Sanbio, outside the submitted work. Dr. Okano has a patent on a therapeutic agent for ALS and composition for treatment licensed to K Pharma. The other authors’ disclosures and additional information are available in the original article. Dr. Armon reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Ropinirole, a drug used for Parkinson’s disease (PD), shows promise in slowing the progression of amyotrophic lateral sclerosis (ALS), early research suggests. However, at least one expert believes the study has “significant flaws.”
 

Investigators randomly assigned 20 individuals with sporadic ALS to receive either ropinirole or placebo for 24 weeks. During the double-blind period, there was no difference between the groups in terms of decline in functional status.

However, during a further open-label extension period, the ropinirole group showed significant suppression of functional decline and an average of an additional 7 months of progression-free survival.

The researchers were able to predict clinical responsiveness to ropinirole in vitro by analyzing motor neurons derived from participants’ stem cells.

“We found that ropinirole is safe and tolerable for ALS patients and shows therapeutic promise at helping them sustain daily activity and muscle strength,” first author Satoru Morimoto, MD, of the department of physiology, Keio University School of Medicine, Tokyo, said in a news release.

The study was published online in Cell Stem Cell.
 

Feasibility study

“ALS is totally incurable and it’s a very difficult disease to treat,” senior author Hideyuki Okano, MD, PhD, professor, department of physiology, Keio University, said in the news release.

Preclinical animal models have “limited translational potential” for identifying drug candidates, but induced pluripotent stem cell (iPSC)–derived motor neurons (MNs) from ALS patients can “overcome these limitations for drug screening,” the authors write.

“We previously identified ropinirole [a dopamine D2 receptor agonist] as a potential anti-ALS drug in vitro by iPSC drug discovery,” Dr. Okano said.

The current trial was a randomized, placebo-controlled phase 1/2a feasibility trial that evaluated the safety, tolerability, and efficacy of ropinirole in patients with ALS, using several parameters:

• The revised ALS functional rating scale (ALSFRS-R) score.
• Composite functional endpoints.
• Event-free survival.
• Time to ≤ 50% forced vital capacity (FVC).

The trial consisted of a 12-week run-in period, a 24-week double-blind period, an open-label extension period that lasted from 4 to 24 weeks, and a 4-week follow-up period after administration.

Thirteen patients were assigned to receive ropinirole (23.1% women; mean age, 65.2 ± 12.6 years; 7.7% with clinically definite and 76.9% with clinically probable ALS); seven were assigned to receive placebo (57.1% women; mean age, 66.3 ± 7.5 years; 14.3% with clinically definite and 85.7% with clinically probable ALS).

Of the treatment group, 30.8% had a bulbar onset lesion vs. 57.1% in the placebo group. At baseline, the mean FVC was 94.4% ± 14.9 and 81.5% ± 23.2 in the ropinirole and placebo groups, respectively. The mean body mass index (BMI) was 22.91 ± 3.82 and 19.69 ± 2.63, respectively.

Of the participants,12 in the ropinirole and six in the control group completed the full 24-week treatment protocol; 12 in the ropinirole and five in the placebo group completed the open-label extension (participants who had received placebo were switched to the active drug).

However only seven participants in the ropinirole group and one participant in the placebo group completed the full 1-year trial.
 

‘Striking correlation’

“During the double-blind period, muscle strength and daily activity were maintained, but a decline in the ALSFRS-R … was not different from that in the placebo group,” the researchers write.

In the open-label extension period, the ropinirole group showed “significant suppression of ALSFRS-R decline,” with an ALSFRS-R score change of only 7.75 (95% confidence interval, 10.66-4.63) for the treatment group vs. 17.51 (95% CI, 22.46-12.56) for the placebo group.

The researchers used the assessment of function and survival (CAFS) score, which adjusts the ALSFRS-R score against mortality, to see whether functional benefits translated into improved survival.

The score “favored ropinirole” in the open-extension period and the entire treatment period but not in the double-blind period.

164031_graphic_web.jpg

Significant flaws

Commenting for this article, Carmel Armon, MD, MHS, professor of neurology, Loma Linda (Calif.) University, said the study “falls short of being a credible 1/2a clinical trial.”

Although the “intentions were good and the design not unusual,” the two groups were not “balanced on risk factors for faster progressing disease.” Rather, the placebo group was “tilted towards faster progressing disease” because there were more clinically definite and probable ALS patients in the placebo group than the treatment group, and there were more patients with bulbar onset.

Participants in the placebo group also had shorter median disease duration, lower BMI, and lower FVC, noted Dr. Armon, who was not involved with the study.

And only 1 in 7 control patients completed the open-label extension, compared with 7 of 13 patients in the intervention group.

“With these limitations, I would be disinclined to rely on the findings to justify a larger clinical trial,” Dr. Armon concluded.

The trial was sponsored by K Pharma. The study drug, active drugs, and placebo were supplied free of charge by GlaxoSmithKline K.K. Dr. Okano received grants from JSPS and AMED and grants and personal fees from K Pharma during the conduct of the study and personal fees from Sanbio, outside the submitted work. Dr. Okano has a patent on a therapeutic agent for ALS and composition for treatment licensed to K Pharma. The other authors’ disclosures and additional information are available in the original article. Dr. Armon reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Ropinirole, a drug used for Parkinson’s disease (PD), shows promise in slowing the progression of amyotrophic lateral sclerosis (ALS), early research suggests. However, at least one expert believes the study has “significant flaws.”
 

Investigators randomly assigned 20 individuals with sporadic ALS to receive either ropinirole or placebo for 24 weeks. During the double-blind period, there was no difference between the groups in terms of decline in functional status.

However, during a further open-label extension period, the ropinirole group showed significant suppression of functional decline and an average of an additional 7 months of progression-free survival.

The researchers were able to predict clinical responsiveness to ropinirole in vitro by analyzing motor neurons derived from participants’ stem cells.

“We found that ropinirole is safe and tolerable for ALS patients and shows therapeutic promise at helping them sustain daily activity and muscle strength,” first author Satoru Morimoto, MD, of the department of physiology, Keio University School of Medicine, Tokyo, said in a news release.

The study was published online in Cell Stem Cell.
 

Feasibility study

“ALS is totally incurable and it’s a very difficult disease to treat,” senior author Hideyuki Okano, MD, PhD, professor, department of physiology, Keio University, said in the news release.

Preclinical animal models have “limited translational potential” for identifying drug candidates, but induced pluripotent stem cell (iPSC)–derived motor neurons (MNs) from ALS patients can “overcome these limitations for drug screening,” the authors write.

“We previously identified ropinirole [a dopamine D2 receptor agonist] as a potential anti-ALS drug in vitro by iPSC drug discovery,” Dr. Okano said.

The current trial was a randomized, placebo-controlled phase 1/2a feasibility trial that evaluated the safety, tolerability, and efficacy of ropinirole in patients with ALS, using several parameters:

• The revised ALS functional rating scale (ALSFRS-R) score.
• Composite functional endpoints.
• Event-free survival.
• Time to ≤ 50% forced vital capacity (FVC).

The trial consisted of a 12-week run-in period, a 24-week double-blind period, an open-label extension period that lasted from 4 to 24 weeks, and a 4-week follow-up period after administration.

Thirteen patients were assigned to receive ropinirole (23.1% women; mean age, 65.2 ± 12.6 years; 7.7% with clinically definite and 76.9% with clinically probable ALS); seven were assigned to receive placebo (57.1% women; mean age, 66.3 ± 7.5 years; 14.3% with clinically definite and 85.7% with clinically probable ALS).

Of the treatment group, 30.8% had a bulbar onset lesion vs. 57.1% in the placebo group. At baseline, the mean FVC was 94.4% ± 14.9 and 81.5% ± 23.2 in the ropinirole and placebo groups, respectively. The mean body mass index (BMI) was 22.91 ± 3.82 and 19.69 ± 2.63, respectively.

Of the participants,12 in the ropinirole and six in the control group completed the full 24-week treatment protocol; 12 in the ropinirole and five in the placebo group completed the open-label extension (participants who had received placebo were switched to the active drug).

However only seven participants in the ropinirole group and one participant in the placebo group completed the full 1-year trial.
 

‘Striking correlation’

“During the double-blind period, muscle strength and daily activity were maintained, but a decline in the ALSFRS-R … was not different from that in the placebo group,” the researchers write.

In the open-label extension period, the ropinirole group showed “significant suppression of ALSFRS-R decline,” with an ALSFRS-R score change of only 7.75 (95% confidence interval, 10.66-4.63) for the treatment group vs. 17.51 (95% CI, 22.46-12.56) for the placebo group.

The researchers used the assessment of function and survival (CAFS) score, which adjusts the ALSFRS-R score against mortality, to see whether functional benefits translated into improved survival.

The score “favored ropinirole” in the open-extension period and the entire treatment period but not in the double-blind period.

164031_graphic_web.jpg

Significant flaws

Commenting for this article, Carmel Armon, MD, MHS, professor of neurology, Loma Linda (Calif.) University, said the study “falls short of being a credible 1/2a clinical trial.”

Although the “intentions were good and the design not unusual,” the two groups were not “balanced on risk factors for faster progressing disease.” Rather, the placebo group was “tilted towards faster progressing disease” because there were more clinically definite and probable ALS patients in the placebo group than the treatment group, and there were more patients with bulbar onset.

Participants in the placebo group also had shorter median disease duration, lower BMI, and lower FVC, noted Dr. Armon, who was not involved with the study.

And only 1 in 7 control patients completed the open-label extension, compared with 7 of 13 patients in the intervention group.

“With these limitations, I would be disinclined to rely on the findings to justify a larger clinical trial,” Dr. Armon concluded.

The trial was sponsored by K Pharma. The study drug, active drugs, and placebo were supplied free of charge by GlaxoSmithKline K.K. Dr. Okano received grants from JSPS and AMED and grants and personal fees from K Pharma during the conduct of the study and personal fees from Sanbio, outside the submitted work. Dr. Okano has a patent on a therapeutic agent for ALS and composition for treatment licensed to K Pharma. The other authors’ disclosures and additional information are available in the original article. Dr. Armon reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

An oral oil containing tetrahydrocannabinol (THC) and cannabidiol (CBD) led to a significant and meaningful reduction in motor and vocal tics in patients with severe Tourette syndrome (TS), results of a double-blind, placebo-controlled, crossover study show.

“In a methodologically robust manner (and independent of any drug company sponsorship), we provide evidence for the effectiveness of repeated dosing with THC:CBD vs. placebo in tic suppression, as well as reduction of comorbid anxiety and obsessive-compulsive disorder in severe TS,” neuropsychiatrist and lead investigator Philip Mosley, PhD, said in an interview.

The results offer support to people with TS who “want to approach their doctor to try medicinal cannabis when other drugs have not worked or are intolerable,” said Dr. Mosley, of the Wesley Research Institute and QIMR Berghofer Medical Research Institute, Herston, Australia.

The study was published online in NEJM Evidence.
 

A viable treatment option

Twenty-two adults (mean age, 31 years) with severe TS received THC:CBD oil titrated upward over 6 weeks to a daily dose of 20 mg of THC and 20 mg of CBD, followed by a 6-week course of placebo (or vice versa). Six participants had not previously used cannabis.

The primary outcome was the total tic score on the Yale Global Tic Severity Scale (YGTSS; range 0 to 50 with higher scores = greater tic severity).

The mean baseline YGTSS total tic score was 35.7. At 6 weeks, the reduction in total tic score was 8.9 with THC:CBD vs. 2.5 with placebo.

A linear mixed-effects model (intention-to-treat) showed a significant interaction of treatment and visit number (P = .008), indicating a greater decrease (improvement) in tic score over time with THC:CBD, the study team reported.

On average, the magnitude of the tic reduction was “moderate” and comparable to the effect observed with existing treatments such as antipsychotic agents, the investigators noted.

THC:CBD also led to a reduction in other symptoms associated with TS, particularly symptoms of OCD and anxiety.

The symptomatic response to THC:CBD correlated with serum metabolites of the cannabinoids, further supporting a biological relationship, the researchers noted.

There were no serious adverse events. Adverse effects with THC:CBD were generally mild. The most common adverse effect was cognitive difficulties, including slowed mentation, memory lapses, and poor concentration.

“Like many studies of psychoactive compounds, blinding among participants was a problem,” the researchers noted. Despite best efforts to conceal treatment allocation and match placebo to the active agent in terms of color and smell, most participants were able to correctly guess their treatment order.

Based on the findings in this small trial, larger and longer trials of THC:CBD in TS are warranted, they concluded.

“We need a plurality of treatment options in Tourette syndrome. For some, antipsychotics are effective tic-suppressing agents but for many these benefits are complicated by side effects such as weight gain & sedation,” Dr. Mosley tweeted. “Cannabinoids are a biologically plausible therapeutic agent. The body’s own ‘endocannabinoid’ receptors are concentrated in the basal ganglia – the neuroanatomical nexus of TS.”

The study was funded by the Wesley Medical Research Institute, Brisbane, and the Lambert Initiative for Cannabinoid Therapeutics, a philanthropically funded research organization at the University of Sydney, Australia. Dr. Mosley reports no relevant financial relationships.
 

A version of this article first appeared on Medscape.com.

An oral oil containing tetrahydrocannabinol (THC) and cannabidiol (CBD) led to a significant and meaningful reduction in motor and vocal tics in patients with severe Tourette syndrome (TS), results of a double-blind, placebo-controlled, crossover study show.

“In a methodologically robust manner (and independent of any drug company sponsorship), we provide evidence for the effectiveness of repeated dosing with THC:CBD vs. placebo in tic suppression, as well as reduction of comorbid anxiety and obsessive-compulsive disorder in severe TS,” neuropsychiatrist and lead investigator Philip Mosley, PhD, said in an interview.

The results offer support to people with TS who “want to approach their doctor to try medicinal cannabis when other drugs have not worked or are intolerable,” said Dr. Mosley, of the Wesley Research Institute and QIMR Berghofer Medical Research Institute, Herston, Australia.

The study was published online in NEJM Evidence.
 

A viable treatment option

Twenty-two adults (mean age, 31 years) with severe TS received THC:CBD oil titrated upward over 6 weeks to a daily dose of 20 mg of THC and 20 mg of CBD, followed by a 6-week course of placebo (or vice versa). Six participants had not previously used cannabis.

The primary outcome was the total tic score on the Yale Global Tic Severity Scale (YGTSS; range 0 to 50 with higher scores = greater tic severity).

The mean baseline YGTSS total tic score was 35.7. At 6 weeks, the reduction in total tic score was 8.9 with THC:CBD vs. 2.5 with placebo.

A linear mixed-effects model (intention-to-treat) showed a significant interaction of treatment and visit number (P = .008), indicating a greater decrease (improvement) in tic score over time with THC:CBD, the study team reported.

On average, the magnitude of the tic reduction was “moderate” and comparable to the effect observed with existing treatments such as antipsychotic agents, the investigators noted.

THC:CBD also led to a reduction in other symptoms associated with TS, particularly symptoms of OCD and anxiety.

The symptomatic response to THC:CBD correlated with serum metabolites of the cannabinoids, further supporting a biological relationship, the researchers noted.

There were no serious adverse events. Adverse effects with THC:CBD were generally mild. The most common adverse effect was cognitive difficulties, including slowed mentation, memory lapses, and poor concentration.

“Like many studies of psychoactive compounds, blinding among participants was a problem,” the researchers noted. Despite best efforts to conceal treatment allocation and match placebo to the active agent in terms of color and smell, most participants were able to correctly guess their treatment order.

Based on the findings in this small trial, larger and longer trials of THC:CBD in TS are warranted, they concluded.

“We need a plurality of treatment options in Tourette syndrome. For some, antipsychotics are effective tic-suppressing agents but for many these benefits are complicated by side effects such as weight gain & sedation,” Dr. Mosley tweeted. “Cannabinoids are a biologically plausible therapeutic agent. The body’s own ‘endocannabinoid’ receptors are concentrated in the basal ganglia – the neuroanatomical nexus of TS.”

The study was funded by the Wesley Medical Research Institute, Brisbane, and the Lambert Initiative for Cannabinoid Therapeutics, a philanthropically funded research organization at the University of Sydney, Australia. Dr. Mosley reports no relevant financial relationships.
 

A version of this article first appeared on Medscape.com.

An oral oil containing tetrahydrocannabinol (THC) and cannabidiol (CBD) led to a significant and meaningful reduction in motor and vocal tics in patients with severe Tourette syndrome (TS), results of a double-blind, placebo-controlled, crossover study show.

“In a methodologically robust manner (and independent of any drug company sponsorship), we provide evidence for the effectiveness of repeated dosing with THC:CBD vs. placebo in tic suppression, as well as reduction of comorbid anxiety and obsessive-compulsive disorder in severe TS,” neuropsychiatrist and lead investigator Philip Mosley, PhD, said in an interview.

The results offer support to people with TS who “want to approach their doctor to try medicinal cannabis when other drugs have not worked or are intolerable,” said Dr. Mosley, of the Wesley Research Institute and QIMR Berghofer Medical Research Institute, Herston, Australia.

The study was published online in NEJM Evidence.
 

A viable treatment option

Twenty-two adults (mean age, 31 years) with severe TS received THC:CBD oil titrated upward over 6 weeks to a daily dose of 20 mg of THC and 20 mg of CBD, followed by a 6-week course of placebo (or vice versa). Six participants had not previously used cannabis.

The primary outcome was the total tic score on the Yale Global Tic Severity Scale (YGTSS; range 0 to 50 with higher scores = greater tic severity).

The mean baseline YGTSS total tic score was 35.7. At 6 weeks, the reduction in total tic score was 8.9 with THC:CBD vs. 2.5 with placebo.

A linear mixed-effects model (intention-to-treat) showed a significant interaction of treatment and visit number (P = .008), indicating a greater decrease (improvement) in tic score over time with THC:CBD, the study team reported.

On average, the magnitude of the tic reduction was “moderate” and comparable to the effect observed with existing treatments such as antipsychotic agents, the investigators noted.

THC:CBD also led to a reduction in other symptoms associated with TS, particularly symptoms of OCD and anxiety.

The symptomatic response to THC:CBD correlated with serum metabolites of the cannabinoids, further supporting a biological relationship, the researchers noted.

There were no serious adverse events. Adverse effects with THC:CBD were generally mild. The most common adverse effect was cognitive difficulties, including slowed mentation, memory lapses, and poor concentration.

“Like many studies of psychoactive compounds, blinding among participants was a problem,” the researchers noted. Despite best efforts to conceal treatment allocation and match placebo to the active agent in terms of color and smell, most participants were able to correctly guess their treatment order.

Based on the findings in this small trial, larger and longer trials of THC:CBD in TS are warranted, they concluded.

“We need a plurality of treatment options in Tourette syndrome. For some, antipsychotics are effective tic-suppressing agents but for many these benefits are complicated by side effects such as weight gain & sedation,” Dr. Mosley tweeted. “Cannabinoids are a biologically plausible therapeutic agent. The body’s own ‘endocannabinoid’ receptors are concentrated in the basal ganglia – the neuroanatomical nexus of TS.”

The study was funded by the Wesley Medical Research Institute, Brisbane, and the Lambert Initiative for Cannabinoid Therapeutics, a philanthropically funded research organization at the University of Sydney, Australia. Dr. Mosley reports no relevant financial relationships.
 

A version of this article first appeared on Medscape.com.