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AMSTERDAM – Over the past couple of years, integrase inhibitors have become the preferred anchor drug worldwide for HIV-treatment regimens. But in May 2018, researchers first reported an unexpected signal that one drug from the class, dolutegravir, showed a statistically significant link with an increased rate of neural-tube defects in neonates born to women in Botswana who had received dolutegravir at the time they conceived.
The data showed a 0.94% incidence of a neonate born with a neural-tube defect (NTD) among 426 HIV-infected women who were taking dolutegravir when they became pregnant. While this surprising finding remains preliminary because of limited number of women studied so far, and although the magnitude of the apparent effect fell somewhat after factoring in no further infants born with an NTD among 170 additional exposed women, the suggestion of an important teratogenic effect from dolutegravir led to a special session during the 22nd International AIDS Conference. The overwhelming consensus from this session seemed to be that the possible excess of NTDs linked with treatment with an integrase strand transfer inhibitor (INSTI) at the start of pregnancy was concerning enough to suggest caution and extra counseling for women of childbearing potential, but it was by no means a reason to derail the worldwide shift to the INSTI drug class as the core agent for treating HIV.
“Dolutegravir has been a beacon of hope for treating HIV,” said Maggie Little, PhD, a professor of philosophy and medical ethicist at Georgetown University in Washington. “Dolutegravir offers substantial benefits to quality of life in addition to reducing women’s mortality.” The new finding of excess NTDs “appears to pit pregnant women against their children. But the numbers never tell us the answer; it’s not arithmetic.” The appropriate public health response should focus on “supporting meaningful choice by women,” Dr. Little said during a talk at the session. “Policies must be made in ongoing consultation with communities of women who live with HIV.”
Rise of the INSTIs
The International AIDS Conference showcased the contrast between the benefits of the INSTIs and their possible perils.
Well before news of the NTD signal came out, the conference program featured a plenary talk from Pedro Cahn, MD, PhD, entitled “Moving into the Integrase Era.” During his talk, Dr. Cahn proclaimed that HIV treatment is “moving toward the integrase world,” and recently featured “unprecedented rollout” in low-income countries. In addition to dolutegravir (Tivicay) the INSTI class includes raltegravir (Isentress), elvitegravir (Vitekta), and bictegravir (Symtuza).
Dr. Cahn attributed the first-line status of the INSTIs to several factors: their higher antiviral activity, compared with every other anti-HIV drug including proven superior efficacy to efavirenz (Sustiva) – the former core drug for antiretroviral regimens, rapid viral suppression, good tolerability with a low rate of treatment discontinuations, good recovery of CD4 cells, a relatively high genetic barrier to selection of HIV resistance mutations with relatively few resistant mutations seen when used in combination regimen’s in treatment-naive patients, and few drug-drug interactions, By mid-2018, dolutegravir or another INSTI had been named part of a first-line HIV treatment regimen by several countries and by the World Health Organization; according to WHO data, by mid-2018 more than half the low- and middle-income countries of the world had endorsed an INSTI-containing regimen including Botswana, Brazil, Kenya, Nigeria, and Uganda, said Dr. Cahn, scientific director of the Huésbed Foundation in Buenos Aires.
One example of the success that dolutegravir has recently shown as first-line treatment came in data reported at the Conference from Brazil. where a three-drug regimen containing dolutegravir plus lamivudine (3TC; Epivir) and tenofovir (TDF; Viread) replaced a triple regimen of efavirenz plus 3TC and TDF as recommended first-line treatment in 2017. Data collected by the Brazilian Ministry of Health during January 2014-June 2017 identified 103,240 people at least 15 years old who received treatment for HIV. The review showed that 85% of people treated with a dolutegravir-containing regimen had successful viral suppression to an undetectable level, compared with 78% of people on the same regimen but with efavirenz instead of dolutegravir, Mariana V. Meireles reported at the conference. Other triple-drug regimens had even lower rates of viral suppression. After researchers controlled for the age, sex, level of adherence, and baseline viral load and CD4 cell count the people who received the dolutegravir-containing regimen had at least a 42% higher rate of undetectable virus compared with any other regimen used by Brazilian patients, said Ms. Meireles, a researcher with the Brazilian Ministry of Health in Brasilia.
Dr. Cahn acknowledged the current concern and uncertainty about INSTIs and NTDs. “Caution and effective contraception are recommended for dolutegravir. The risks and benefits should be compared with other [treatment] options. Women have the right to make informed choices,” he said. Dr. Cahn also highlighted that safety analyses need data from additional early-pregnancy exposures to clearly rule in or rule out a teratogenic effect from dolutegravir. And he stressed that, whether or not the possible NTD link is a class effect remains to be assessed as data from early-pregnancy exposures of women on other INSTIs are currently much more limited than they are those for dolutegravir. He also raised a question voiced by others: Is the effect from dolutegravir somehow mediated by folic acid levels, a dietary component that protects against NTDs? Botswana, the country that generated the NTD data, doesn’t fortify wheat flour or any other food with folic acid, as occurs in the United States, noted Rebecca M. Zash, MD, the researcher who led the Botswana study.
The NTD data
The signal for an NTD link to dolutegravir came from a study run in Botswana designed for a totally different, albeit related purpose. The Tsepamo study launched in 2014 with the goal of assessing the safety of efavirenz-based HIV regimens when used by pregnant women. The study has run at eight of the country’s largest maternity wards, where nearly half of Botswana’s deliveries occur. The midwives at those locations collected data on all women at their clinics, and once Botswana adopted dolutegravir as its anchor drug of choice for treating people infected with HIV in 2017 significant numbers of the women in the Tsepamo study received dolutegravir. Through May 1, 2018, the study had enrolled more than 89,000 women who had 88,755 live births, including nearly 22,000 women infected with HIV (and more than 66,000 without infection), nearly 12,00 of those infected with HIV who received some type of antiretroviral therapy, 5,787 on efavirenz at the time of conception, 2,812 women who started on dolutegravir treatment during pregnancy, and 426 women who were on dolutegravir at the time of conception, said Dr. Zash, an infectious diseases physician at Beth Israel Deaconess Hospital in Boston and codirector of the Reproductive Health for HIV-Infected Populations Study Working Group at the Harvard University Center for AIDS Research in Cambridge, Mass.
A recently published analysis by Dr. Zash and her associates found no difference in the incidence rate of adverse birth outcomes among women who started on either efavirenz or dolutegravir during pregnancy. This analysis also showed that women infected with HIV overall had “mildly increased” rates of both total adverse birth outcomes and severe adverse birth outcomes compared with women without HIV infection (Lancet Glob Health. 2018 Jul;6[7]:e804-e10).
When the researchers looked at NTDs among neonates born to women exposed at conception, they saw a different picture. The entire cohort of nearly 89,000 live births included 86 neonates with an NTD, a 0.1% rate. This included 4 of the 426 births from mothers on dolutegravir at conception, a 0.94% rate, significantly higher than the overall rate. Other comparator NTD rates included a 0,12% incidence among mothers on any anti-HIV drug other than dolutegravir at conception, a 0.09% rate among mothers who were not infected with HIV, and a 0.05% rate among mothers on efavirenz at conception, Dr. Zash and her associates reported in a publication that appeared coincident with her talk at the conference (N Engl J Med. 2018 Jul 24.doi: 10.1056/NEJMc1807653). The NTDs linked with dolutegravir use involved four distinct types of NTD, a finding Dr. Zash called “unusual,” but not unique among teratogens.
During her talk, Dr. Zash further updated the dolutegravir numbers based on extended follow-up of the Botswana cohort during May 1-July 15, during which time two NTDs occurred, one involving an uninfected mother and the second from a mother who started on dolutegravir at 8 weeks’ gestational age, after the time when NTDs occur. Further follow-up also added 170 more neonates born to women exposed to dolutegravir at conception, bringing the total now to 596 births with 4 NTDs or a rate of 0.67%, still significantly elevated, compared with other exposure groups. The Tsepamo study continues, with an additional 10 sites planned to soon join that will boost maternity coverage to 72% of Botswana’s annual births. The next planned analysis is in March 2019, and by then the number of neonates born to women with early dolutegravir exposure should more than double, Dr. Zash predicted.
Modeling the risks and benefits
Identifying a possible excess of NTDs with dolutegravir treatment in adolescent girls and young women doesn’t, of course, tell the whole risk-benefit story for dolutegravir and possibly the other INSTIs. Caitlin Dugdale, MD, an infectious diseases physician at Massachusetts General Hospital in Boston, reported a model she developed to better define the pluses and minuses of dolutegravir treatment, compared with efavirenz. The model used projections for women in South Africa of child-bearing potential infected by HIV over the next 5 years and used data on drug efficacy and harms based on published reports. For example, the ability of the two drugs to produce undetectable viral loads was assumed by the model to be 94% after 48 weeks on treatment with dolutegravir and 86% with efavirenz, based on the rates reported in the phase 3, randomized comparison of dolutegravir- and efavirenz-based regimens in the SINGLE trial, with adjustments for factors such as protocol deviations and mortality that were accounted for in other parts of the model, Dr. Dugdale said. She used estimates for NTD incidence based on the published numbers reported by Dr. Zash.
The results showed that, over the next 5 years, based on just the existing and projected rates of HIV infection, treating all infected women and children with a dolutegravir-based regimen instead of a regimen anchored by efavirenz would result in the benefits of 28,400 fewer deaths among women, 52,800 fewer sexual transmissions of HIV, 5,000 fewer pediatric HIV transmissions, and 1,600 fewer pediatric deaths unrelated to an NTD. On the minus side relying on dolutegravir instead of efavirenz was projected to cause an excess of 10,000 neonates born with an NTD, 8,400 excess pediatric deaths, and overall 5,400 fewer children alive and free from HIV. These projections were based on 3.5 million women on first-line treatment with antiretroviral therapy and 1.1 million children born with HIV exposure.
Dr. Dugdale drew particular attention to the comparison between 28,400 fewer deaths among women when treated with dolutegravir at the cost of 8,400 excess pediatric deaths, but cautioned that this creates “a difficult trade-off to balance.” Findings from the model and other information on HIV treatment options should enter into the decision making of each HIV-infected woman who could become pregnant, she said. It’s important that patients view the risks and benefits not just on a population level but on an individual, personal level, Dr. Dugdale said in a video interview. “The individual woman must balance the risks and benefits for herself and her child.”
“Patients need to decide what is important to them,” agreed Dr. Zash during the conference.
The NTD findings also underscored the importance of better contraception options for HIV-infected women. “This is an opportunity to improve reproductive health and contraception for women, especially in resource-poor countries,” commented Elaine J. Abrams, MD, professor of epidemiology and pediatrics at Columbia University in New York, who cochaired the conference session.
Another lesson from the NTD findings is the importance of tracking the safety of new drugs used when women become pregnant and during pregnancy. The dolutegravir arm of the Tsepamo study “was almost by accident,” noted the Georgetown medical ethicist, Dr. Little. “Every new treatment should be examined in pregnant women and infants,” she added. “Studies like this should not be left to chance. Women deserve an evidence base for medication use across the lifespan including during pregnancy and periconception.”
Dr. Little, Ms. Meireles, Dr. Zash, and Dr. Dugdale had no disclosures. Dr. Cahn has been an adviser to or speaker for AbbVie, Merck, and ViiV and has received research funding from AbbVie, Merck, ViiV, and Richmond. Dr. Abrams has been an adviser to Merck and ViiV. Viiv is the company that markets dolutegravir.
AMSTERDAM – Over the past couple of years, integrase inhibitors have become the preferred anchor drug worldwide for HIV-treatment regimens. But in May 2018, researchers first reported an unexpected signal that one drug from the class, dolutegravir, showed a statistically significant link with an increased rate of neural-tube defects in neonates born to women in Botswana who had received dolutegravir at the time they conceived.
The data showed a 0.94% incidence of a neonate born with a neural-tube defect (NTD) among 426 HIV-infected women who were taking dolutegravir when they became pregnant. While this surprising finding remains preliminary because of limited number of women studied so far, and although the magnitude of the apparent effect fell somewhat after factoring in no further infants born with an NTD among 170 additional exposed women, the suggestion of an important teratogenic effect from dolutegravir led to a special session during the 22nd International AIDS Conference. The overwhelming consensus from this session seemed to be that the possible excess of NTDs linked with treatment with an integrase strand transfer inhibitor (INSTI) at the start of pregnancy was concerning enough to suggest caution and extra counseling for women of childbearing potential, but it was by no means a reason to derail the worldwide shift to the INSTI drug class as the core agent for treating HIV.
“Dolutegravir has been a beacon of hope for treating HIV,” said Maggie Little, PhD, a professor of philosophy and medical ethicist at Georgetown University in Washington. “Dolutegravir offers substantial benefits to quality of life in addition to reducing women’s mortality.” The new finding of excess NTDs “appears to pit pregnant women against their children. But the numbers never tell us the answer; it’s not arithmetic.” The appropriate public health response should focus on “supporting meaningful choice by women,” Dr. Little said during a talk at the session. “Policies must be made in ongoing consultation with communities of women who live with HIV.”
Rise of the INSTIs
The International AIDS Conference showcased the contrast between the benefits of the INSTIs and their possible perils.
Well before news of the NTD signal came out, the conference program featured a plenary talk from Pedro Cahn, MD, PhD, entitled “Moving into the Integrase Era.” During his talk, Dr. Cahn proclaimed that HIV treatment is “moving toward the integrase world,” and recently featured “unprecedented rollout” in low-income countries. In addition to dolutegravir (Tivicay) the INSTI class includes raltegravir (Isentress), elvitegravir (Vitekta), and bictegravir (Symtuza).
Dr. Cahn attributed the first-line status of the INSTIs to several factors: their higher antiviral activity, compared with every other anti-HIV drug including proven superior efficacy to efavirenz (Sustiva) – the former core drug for antiretroviral regimens, rapid viral suppression, good tolerability with a low rate of treatment discontinuations, good recovery of CD4 cells, a relatively high genetic barrier to selection of HIV resistance mutations with relatively few resistant mutations seen when used in combination regimen’s in treatment-naive patients, and few drug-drug interactions, By mid-2018, dolutegravir or another INSTI had been named part of a first-line HIV treatment regimen by several countries and by the World Health Organization; according to WHO data, by mid-2018 more than half the low- and middle-income countries of the world had endorsed an INSTI-containing regimen including Botswana, Brazil, Kenya, Nigeria, and Uganda, said Dr. Cahn, scientific director of the Huésbed Foundation in Buenos Aires.
One example of the success that dolutegravir has recently shown as first-line treatment came in data reported at the Conference from Brazil. where a three-drug regimen containing dolutegravir plus lamivudine (3TC; Epivir) and tenofovir (TDF; Viread) replaced a triple regimen of efavirenz plus 3TC and TDF as recommended first-line treatment in 2017. Data collected by the Brazilian Ministry of Health during January 2014-June 2017 identified 103,240 people at least 15 years old who received treatment for HIV. The review showed that 85% of people treated with a dolutegravir-containing regimen had successful viral suppression to an undetectable level, compared with 78% of people on the same regimen but with efavirenz instead of dolutegravir, Mariana V. Meireles reported at the conference. Other triple-drug regimens had even lower rates of viral suppression. After researchers controlled for the age, sex, level of adherence, and baseline viral load and CD4 cell count the people who received the dolutegravir-containing regimen had at least a 42% higher rate of undetectable virus compared with any other regimen used by Brazilian patients, said Ms. Meireles, a researcher with the Brazilian Ministry of Health in Brasilia.
Dr. Cahn acknowledged the current concern and uncertainty about INSTIs and NTDs. “Caution and effective contraception are recommended for dolutegravir. The risks and benefits should be compared with other [treatment] options. Women have the right to make informed choices,” he said. Dr. Cahn also highlighted that safety analyses need data from additional early-pregnancy exposures to clearly rule in or rule out a teratogenic effect from dolutegravir. And he stressed that, whether or not the possible NTD link is a class effect remains to be assessed as data from early-pregnancy exposures of women on other INSTIs are currently much more limited than they are those for dolutegravir. He also raised a question voiced by others: Is the effect from dolutegravir somehow mediated by folic acid levels, a dietary component that protects against NTDs? Botswana, the country that generated the NTD data, doesn’t fortify wheat flour or any other food with folic acid, as occurs in the United States, noted Rebecca M. Zash, MD, the researcher who led the Botswana study.
The NTD data
The signal for an NTD link to dolutegravir came from a study run in Botswana designed for a totally different, albeit related purpose. The Tsepamo study launched in 2014 with the goal of assessing the safety of efavirenz-based HIV regimens when used by pregnant women. The study has run at eight of the country’s largest maternity wards, where nearly half of Botswana’s deliveries occur. The midwives at those locations collected data on all women at their clinics, and once Botswana adopted dolutegravir as its anchor drug of choice for treating people infected with HIV in 2017 significant numbers of the women in the Tsepamo study received dolutegravir. Through May 1, 2018, the study had enrolled more than 89,000 women who had 88,755 live births, including nearly 22,000 women infected with HIV (and more than 66,000 without infection), nearly 12,00 of those infected with HIV who received some type of antiretroviral therapy, 5,787 on efavirenz at the time of conception, 2,812 women who started on dolutegravir treatment during pregnancy, and 426 women who were on dolutegravir at the time of conception, said Dr. Zash, an infectious diseases physician at Beth Israel Deaconess Hospital in Boston and codirector of the Reproductive Health for HIV-Infected Populations Study Working Group at the Harvard University Center for AIDS Research in Cambridge, Mass.
A recently published analysis by Dr. Zash and her associates found no difference in the incidence rate of adverse birth outcomes among women who started on either efavirenz or dolutegravir during pregnancy. This analysis also showed that women infected with HIV overall had “mildly increased” rates of both total adverse birth outcomes and severe adverse birth outcomes compared with women without HIV infection (Lancet Glob Health. 2018 Jul;6[7]:e804-e10).
When the researchers looked at NTDs among neonates born to women exposed at conception, they saw a different picture. The entire cohort of nearly 89,000 live births included 86 neonates with an NTD, a 0.1% rate. This included 4 of the 426 births from mothers on dolutegravir at conception, a 0.94% rate, significantly higher than the overall rate. Other comparator NTD rates included a 0,12% incidence among mothers on any anti-HIV drug other than dolutegravir at conception, a 0.09% rate among mothers who were not infected with HIV, and a 0.05% rate among mothers on efavirenz at conception, Dr. Zash and her associates reported in a publication that appeared coincident with her talk at the conference (N Engl J Med. 2018 Jul 24.doi: 10.1056/NEJMc1807653). The NTDs linked with dolutegravir use involved four distinct types of NTD, a finding Dr. Zash called “unusual,” but not unique among teratogens.
During her talk, Dr. Zash further updated the dolutegravir numbers based on extended follow-up of the Botswana cohort during May 1-July 15, during which time two NTDs occurred, one involving an uninfected mother and the second from a mother who started on dolutegravir at 8 weeks’ gestational age, after the time when NTDs occur. Further follow-up also added 170 more neonates born to women exposed to dolutegravir at conception, bringing the total now to 596 births with 4 NTDs or a rate of 0.67%, still significantly elevated, compared with other exposure groups. The Tsepamo study continues, with an additional 10 sites planned to soon join that will boost maternity coverage to 72% of Botswana’s annual births. The next planned analysis is in March 2019, and by then the number of neonates born to women with early dolutegravir exposure should more than double, Dr. Zash predicted.
Modeling the risks and benefits
Identifying a possible excess of NTDs with dolutegravir treatment in adolescent girls and young women doesn’t, of course, tell the whole risk-benefit story for dolutegravir and possibly the other INSTIs. Caitlin Dugdale, MD, an infectious diseases physician at Massachusetts General Hospital in Boston, reported a model she developed to better define the pluses and minuses of dolutegravir treatment, compared with efavirenz. The model used projections for women in South Africa of child-bearing potential infected by HIV over the next 5 years and used data on drug efficacy and harms based on published reports. For example, the ability of the two drugs to produce undetectable viral loads was assumed by the model to be 94% after 48 weeks on treatment with dolutegravir and 86% with efavirenz, based on the rates reported in the phase 3, randomized comparison of dolutegravir- and efavirenz-based regimens in the SINGLE trial, with adjustments for factors such as protocol deviations and mortality that were accounted for in other parts of the model, Dr. Dugdale said. She used estimates for NTD incidence based on the published numbers reported by Dr. Zash.
The results showed that, over the next 5 years, based on just the existing and projected rates of HIV infection, treating all infected women and children with a dolutegravir-based regimen instead of a regimen anchored by efavirenz would result in the benefits of 28,400 fewer deaths among women, 52,800 fewer sexual transmissions of HIV, 5,000 fewer pediatric HIV transmissions, and 1,600 fewer pediatric deaths unrelated to an NTD. On the minus side relying on dolutegravir instead of efavirenz was projected to cause an excess of 10,000 neonates born with an NTD, 8,400 excess pediatric deaths, and overall 5,400 fewer children alive and free from HIV. These projections were based on 3.5 million women on first-line treatment with antiretroviral therapy and 1.1 million children born with HIV exposure.
Dr. Dugdale drew particular attention to the comparison between 28,400 fewer deaths among women when treated with dolutegravir at the cost of 8,400 excess pediatric deaths, but cautioned that this creates “a difficult trade-off to balance.” Findings from the model and other information on HIV treatment options should enter into the decision making of each HIV-infected woman who could become pregnant, she said. It’s important that patients view the risks and benefits not just on a population level but on an individual, personal level, Dr. Dugdale said in a video interview. “The individual woman must balance the risks and benefits for herself and her child.”
“Patients need to decide what is important to them,” agreed Dr. Zash during the conference.
The NTD findings also underscored the importance of better contraception options for HIV-infected women. “This is an opportunity to improve reproductive health and contraception for women, especially in resource-poor countries,” commented Elaine J. Abrams, MD, professor of epidemiology and pediatrics at Columbia University in New York, who cochaired the conference session.
Another lesson from the NTD findings is the importance of tracking the safety of new drugs used when women become pregnant and during pregnancy. The dolutegravir arm of the Tsepamo study “was almost by accident,” noted the Georgetown medical ethicist, Dr. Little. “Every new treatment should be examined in pregnant women and infants,” she added. “Studies like this should not be left to chance. Women deserve an evidence base for medication use across the lifespan including during pregnancy and periconception.”
Dr. Little, Ms. Meireles, Dr. Zash, and Dr. Dugdale had no disclosures. Dr. Cahn has been an adviser to or speaker for AbbVie, Merck, and ViiV and has received research funding from AbbVie, Merck, ViiV, and Richmond. Dr. Abrams has been an adviser to Merck and ViiV. Viiv is the company that markets dolutegravir.
AMSTERDAM – Over the past couple of years, integrase inhibitors have become the preferred anchor drug worldwide for HIV-treatment regimens. But in May 2018, researchers first reported an unexpected signal that one drug from the class, dolutegravir, showed a statistically significant link with an increased rate of neural-tube defects in neonates born to women in Botswana who had received dolutegravir at the time they conceived.
The data showed a 0.94% incidence of a neonate born with a neural-tube defect (NTD) among 426 HIV-infected women who were taking dolutegravir when they became pregnant. While this surprising finding remains preliminary because of limited number of women studied so far, and although the magnitude of the apparent effect fell somewhat after factoring in no further infants born with an NTD among 170 additional exposed women, the suggestion of an important teratogenic effect from dolutegravir led to a special session during the 22nd International AIDS Conference. The overwhelming consensus from this session seemed to be that the possible excess of NTDs linked with treatment with an integrase strand transfer inhibitor (INSTI) at the start of pregnancy was concerning enough to suggest caution and extra counseling for women of childbearing potential, but it was by no means a reason to derail the worldwide shift to the INSTI drug class as the core agent for treating HIV.
“Dolutegravir has been a beacon of hope for treating HIV,” said Maggie Little, PhD, a professor of philosophy and medical ethicist at Georgetown University in Washington. “Dolutegravir offers substantial benefits to quality of life in addition to reducing women’s mortality.” The new finding of excess NTDs “appears to pit pregnant women against their children. But the numbers never tell us the answer; it’s not arithmetic.” The appropriate public health response should focus on “supporting meaningful choice by women,” Dr. Little said during a talk at the session. “Policies must be made in ongoing consultation with communities of women who live with HIV.”
Rise of the INSTIs
The International AIDS Conference showcased the contrast between the benefits of the INSTIs and their possible perils.
Well before news of the NTD signal came out, the conference program featured a plenary talk from Pedro Cahn, MD, PhD, entitled “Moving into the Integrase Era.” During his talk, Dr. Cahn proclaimed that HIV treatment is “moving toward the integrase world,” and recently featured “unprecedented rollout” in low-income countries. In addition to dolutegravir (Tivicay) the INSTI class includes raltegravir (Isentress), elvitegravir (Vitekta), and bictegravir (Symtuza).
Dr. Cahn attributed the first-line status of the INSTIs to several factors: their higher antiviral activity, compared with every other anti-HIV drug including proven superior efficacy to efavirenz (Sustiva) – the former core drug for antiretroviral regimens, rapid viral suppression, good tolerability with a low rate of treatment discontinuations, good recovery of CD4 cells, a relatively high genetic barrier to selection of HIV resistance mutations with relatively few resistant mutations seen when used in combination regimen’s in treatment-naive patients, and few drug-drug interactions, By mid-2018, dolutegravir or another INSTI had been named part of a first-line HIV treatment regimen by several countries and by the World Health Organization; according to WHO data, by mid-2018 more than half the low- and middle-income countries of the world had endorsed an INSTI-containing regimen including Botswana, Brazil, Kenya, Nigeria, and Uganda, said Dr. Cahn, scientific director of the Huésbed Foundation in Buenos Aires.
One example of the success that dolutegravir has recently shown as first-line treatment came in data reported at the Conference from Brazil. where a three-drug regimen containing dolutegravir plus lamivudine (3TC; Epivir) and tenofovir (TDF; Viread) replaced a triple regimen of efavirenz plus 3TC and TDF as recommended first-line treatment in 2017. Data collected by the Brazilian Ministry of Health during January 2014-June 2017 identified 103,240 people at least 15 years old who received treatment for HIV. The review showed that 85% of people treated with a dolutegravir-containing regimen had successful viral suppression to an undetectable level, compared with 78% of people on the same regimen but with efavirenz instead of dolutegravir, Mariana V. Meireles reported at the conference. Other triple-drug regimens had even lower rates of viral suppression. After researchers controlled for the age, sex, level of adherence, and baseline viral load and CD4 cell count the people who received the dolutegravir-containing regimen had at least a 42% higher rate of undetectable virus compared with any other regimen used by Brazilian patients, said Ms. Meireles, a researcher with the Brazilian Ministry of Health in Brasilia.
Dr. Cahn acknowledged the current concern and uncertainty about INSTIs and NTDs. “Caution and effective contraception are recommended for dolutegravir. The risks and benefits should be compared with other [treatment] options. Women have the right to make informed choices,” he said. Dr. Cahn also highlighted that safety analyses need data from additional early-pregnancy exposures to clearly rule in or rule out a teratogenic effect from dolutegravir. And he stressed that, whether or not the possible NTD link is a class effect remains to be assessed as data from early-pregnancy exposures of women on other INSTIs are currently much more limited than they are those for dolutegravir. He also raised a question voiced by others: Is the effect from dolutegravir somehow mediated by folic acid levels, a dietary component that protects against NTDs? Botswana, the country that generated the NTD data, doesn’t fortify wheat flour or any other food with folic acid, as occurs in the United States, noted Rebecca M. Zash, MD, the researcher who led the Botswana study.
The NTD data
The signal for an NTD link to dolutegravir came from a study run in Botswana designed for a totally different, albeit related purpose. The Tsepamo study launched in 2014 with the goal of assessing the safety of efavirenz-based HIV regimens when used by pregnant women. The study has run at eight of the country’s largest maternity wards, where nearly half of Botswana’s deliveries occur. The midwives at those locations collected data on all women at their clinics, and once Botswana adopted dolutegravir as its anchor drug of choice for treating people infected with HIV in 2017 significant numbers of the women in the Tsepamo study received dolutegravir. Through May 1, 2018, the study had enrolled more than 89,000 women who had 88,755 live births, including nearly 22,000 women infected with HIV (and more than 66,000 without infection), nearly 12,00 of those infected with HIV who received some type of antiretroviral therapy, 5,787 on efavirenz at the time of conception, 2,812 women who started on dolutegravir treatment during pregnancy, and 426 women who were on dolutegravir at the time of conception, said Dr. Zash, an infectious diseases physician at Beth Israel Deaconess Hospital in Boston and codirector of the Reproductive Health for HIV-Infected Populations Study Working Group at the Harvard University Center for AIDS Research in Cambridge, Mass.
A recently published analysis by Dr. Zash and her associates found no difference in the incidence rate of adverse birth outcomes among women who started on either efavirenz or dolutegravir during pregnancy. This analysis also showed that women infected with HIV overall had “mildly increased” rates of both total adverse birth outcomes and severe adverse birth outcomes compared with women without HIV infection (Lancet Glob Health. 2018 Jul;6[7]:e804-e10).
When the researchers looked at NTDs among neonates born to women exposed at conception, they saw a different picture. The entire cohort of nearly 89,000 live births included 86 neonates with an NTD, a 0.1% rate. This included 4 of the 426 births from mothers on dolutegravir at conception, a 0.94% rate, significantly higher than the overall rate. Other comparator NTD rates included a 0,12% incidence among mothers on any anti-HIV drug other than dolutegravir at conception, a 0.09% rate among mothers who were not infected with HIV, and a 0.05% rate among mothers on efavirenz at conception, Dr. Zash and her associates reported in a publication that appeared coincident with her talk at the conference (N Engl J Med. 2018 Jul 24.doi: 10.1056/NEJMc1807653). The NTDs linked with dolutegravir use involved four distinct types of NTD, a finding Dr. Zash called “unusual,” but not unique among teratogens.
During her talk, Dr. Zash further updated the dolutegravir numbers based on extended follow-up of the Botswana cohort during May 1-July 15, during which time two NTDs occurred, one involving an uninfected mother and the second from a mother who started on dolutegravir at 8 weeks’ gestational age, after the time when NTDs occur. Further follow-up also added 170 more neonates born to women exposed to dolutegravir at conception, bringing the total now to 596 births with 4 NTDs or a rate of 0.67%, still significantly elevated, compared with other exposure groups. The Tsepamo study continues, with an additional 10 sites planned to soon join that will boost maternity coverage to 72% of Botswana’s annual births. The next planned analysis is in March 2019, and by then the number of neonates born to women with early dolutegravir exposure should more than double, Dr. Zash predicted.
Modeling the risks and benefits
Identifying a possible excess of NTDs with dolutegravir treatment in adolescent girls and young women doesn’t, of course, tell the whole risk-benefit story for dolutegravir and possibly the other INSTIs. Caitlin Dugdale, MD, an infectious diseases physician at Massachusetts General Hospital in Boston, reported a model she developed to better define the pluses and minuses of dolutegravir treatment, compared with efavirenz. The model used projections for women in South Africa of child-bearing potential infected by HIV over the next 5 years and used data on drug efficacy and harms based on published reports. For example, the ability of the two drugs to produce undetectable viral loads was assumed by the model to be 94% after 48 weeks on treatment with dolutegravir and 86% with efavirenz, based on the rates reported in the phase 3, randomized comparison of dolutegravir- and efavirenz-based regimens in the SINGLE trial, with adjustments for factors such as protocol deviations and mortality that were accounted for in other parts of the model, Dr. Dugdale said. She used estimates for NTD incidence based on the published numbers reported by Dr. Zash.
The results showed that, over the next 5 years, based on just the existing and projected rates of HIV infection, treating all infected women and children with a dolutegravir-based regimen instead of a regimen anchored by efavirenz would result in the benefits of 28,400 fewer deaths among women, 52,800 fewer sexual transmissions of HIV, 5,000 fewer pediatric HIV transmissions, and 1,600 fewer pediatric deaths unrelated to an NTD. On the minus side relying on dolutegravir instead of efavirenz was projected to cause an excess of 10,000 neonates born with an NTD, 8,400 excess pediatric deaths, and overall 5,400 fewer children alive and free from HIV. These projections were based on 3.5 million women on first-line treatment with antiretroviral therapy and 1.1 million children born with HIV exposure.
Dr. Dugdale drew particular attention to the comparison between 28,400 fewer deaths among women when treated with dolutegravir at the cost of 8,400 excess pediatric deaths, but cautioned that this creates “a difficult trade-off to balance.” Findings from the model and other information on HIV treatment options should enter into the decision making of each HIV-infected woman who could become pregnant, she said. It’s important that patients view the risks and benefits not just on a population level but on an individual, personal level, Dr. Dugdale said in a video interview. “The individual woman must balance the risks and benefits for herself and her child.”
“Patients need to decide what is important to them,” agreed Dr. Zash during the conference.
The NTD findings also underscored the importance of better contraception options for HIV-infected women. “This is an opportunity to improve reproductive health and contraception for women, especially in resource-poor countries,” commented Elaine J. Abrams, MD, professor of epidemiology and pediatrics at Columbia University in New York, who cochaired the conference session.
Another lesson from the NTD findings is the importance of tracking the safety of new drugs used when women become pregnant and during pregnancy. The dolutegravir arm of the Tsepamo study “was almost by accident,” noted the Georgetown medical ethicist, Dr. Little. “Every new treatment should be examined in pregnant women and infants,” she added. “Studies like this should not be left to chance. Women deserve an evidence base for medication use across the lifespan including during pregnancy and periconception.”
Dr. Little, Ms. Meireles, Dr. Zash, and Dr. Dugdale had no disclosures. Dr. Cahn has been an adviser to or speaker for AbbVie, Merck, and ViiV and has received research funding from AbbVie, Merck, ViiV, and Richmond. Dr. Abrams has been an adviser to Merck and ViiV. Viiv is the company that markets dolutegravir.
REPORTING FROM AIDS 2018