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Novel SERD reduces risk of death by 30% in HR+ breast cancer
Findings from the phase 3 EMERALD trial, presented at the San Antonio Breast Cancer Symposium, revealed that the effects of elacestrant (Menarini and Radius Health) were even more pronounced in women with ESR1 mutations. Women in the elacestrant arm had a 45% reduced risk of death or disease progression in comparison with those who received standard of care.
This new agent is the “first oral SERD to demonstrate a statistically significant and clinically meaningful improvement of progression-free survival in patients with ER-positive/HER2-negative metastatic breast cancer in the second- and third-line settings,” said lead author Aditya Bardia, MD, MPH, director of the breast cancer research program at Mass General Cancer Center and associate professor at Harvard Medical School, both in Boston. “Clinically, elacestrant has the potential to become the new standard of care in the study population.”
Endocrine therapy and CDK4/6 inhibitors remain the mainstay for the management of ER-positive/HER2 metastatic breast cancer. However, most patients will eventually develop resistance to these agents, often caused by the development of ESR1 mutations.
At the current time, fulvestrant is the only SERD available on the U.S. market, which means there is an urgent unmet need for new, effective SERDs in this setting, especially for patients harboring ESR1 mutations, Dr. Bardia explained.
In an early phase 1 trial, Dr. Bardia and his team evaluated elacestrant for safety and antitumor activity and found it had an acceptable safety profile and demonstrated single-agent activity with confirmed partial responses in heavily pretreated patients with ER-positive metastatic breast cancer.
This trial provided the rationale for investigating elacestrant in a phase 3 setting, Dr. Bardia said.
The multicenter, randomized, controlled phase 3 EMERALD trial included 477 postmenopausal women with ER-positive/HER2-negative metastatic breast cancer who had received one or two prior lines of endocrine therapy and no more than one line of chemotherapy in the metastatic setting. Patients had also progressed on prior treatment with a CDK4/6 inhibitor.
Patients were randomized to elacestrant 400 mg orally daily (n = 239) or standard of care (investigator’s choice of fulvestrant or an aromatase inhibitor, n = 238). The cohorts were further stratified by ESR1 mutation status, prior fulvestrant exposure, and presence of visceral disease.
The coprimary endpoints were progression-free survival in patients with tumors harboring ESR1 mutations and in the entire cohort. Secondary endpoints included overall survival, safety, tolerability, and quality of life.
“This was a positive study as it met both primary endpoints,” said Dr. Bardia.
The team found a 30% reduction in the risk of progression or death in the elacestrant arm for all patients (hazard ratio, 0.697; P = .0018) and a 45% (HR, 0.546; P =.0005) reduction in the risk of progression or death among those with ESR1 mutations.
At 12 months, the progression-free survival rate was 22.32% with elacestrant versus 9.42% for those receiving the standard of care. Among the ESR1 mutation group, those rates were slightly more pronounced: 26.76% with elacestrant versus 8.19% with standard of care.
Overall survival data were not yet mature but trended in favor of elacestrant in all patients (HR, 0.751; P = .0821) as well as those with ESR1 mutations (HR, 0.592; P = .0325). The final overall survival analysis is expected next year, Dr. Bardia said.
Common treatment-related adverse events with elacestrant versus standard of care included mostly grade 1 or 2 nausea (25.3% vs. 8.7%), vomiting (11% vs. 2.6%), and fatigue (11% vs. 7.9%). The rate of grade 3 or higher adverse events was 7.2% in the elacestrant arm versus 3.1% in the standard of care group and was mainly driven by nausea. Treatment-emergent adverse events leading to discontinuation of elacestrant or standard of care were infrequent in both arms (6.3% and 4.4%, respectively). No treatment-related deaths occurred in either group.
Dr. Bardia added that further studies are planned and assess the efficacy of elacestrant during earlier lines of treatment and in combination with other therapies, such as CDK4/6 inhibitors.
Weighing in on the recent findings, Carlos Arteaga, MD, who was not involved in the research, said this represents an important study evaluating a therapeutic priority.
“The data suggest that [elacestrant] may be a new option, not only as monotherapy but in combination with other therapies,” Dr. Arteaga, director of Simmons Comprehensive Cancer Center at the University of Texas Southwestern Medical Center, Dallas, and cochair of SABCS, said in an interview.
Coral Omene, MD, PhD, a medical oncologist at Rutgers Cancer Institute of New Jersey and assistant professor of medicine at Robert Wood Johnson Medical School, both in New Brunswick, also commented on the importance of the EMERALD results.
“I would think that this is practice changing,” said Dr. Omene, who was also not involved in the research. The new oral SERD “demonstrates a significant advantage in progression-free survival over either fulvestrant or an aromatase inhibitor.”
An oral drug could also potentially save patients from painful injections that can occasionally result in injection-site abscesses from long-term administration, she explained. “It’s also more convenient to take oral pills at home. It saves on transportation and omits waiting in treatment rooms for administrations.”
Although the overall survival data are not yet mature and the rate of adverse events was higher with elacestrant, “progression-free survival is a surrogate endpoint widely used for overall survival and is reasonable to consider a treatment regimen based on this while awaiting mature survival data,” Dr. Omene added. “The increase in nausea and vomiting seen in oral SERD arm is likely manageable, as there were no significant differences in discontinuation in both arms of treatment.”
The study was supported by Radius Health. Dr. Bardia has served as a consultant or on an advisory board for Radius Health, Pfizer, Novartis, Genentech, Merck, Immunomedics/Gilead, Sanofi, Daiichi Sankyo/AstraZeneca, Phillips, Eli Lilly, and Foundation Medicine. He has conducted contracted research or received grants from Genentech, Novartis, Pfizer, Merck, Sanofi, Radius Health, Immunomedics/Gilead, Daiichi Sankyo/AstraZeneca, Natera, and Eli Lilly.
A version of this article first appeared on Medscape.com.
Findings from the phase 3 EMERALD trial, presented at the San Antonio Breast Cancer Symposium, revealed that the effects of elacestrant (Menarini and Radius Health) were even more pronounced in women with ESR1 mutations. Women in the elacestrant arm had a 45% reduced risk of death or disease progression in comparison with those who received standard of care.
This new agent is the “first oral SERD to demonstrate a statistically significant and clinically meaningful improvement of progression-free survival in patients with ER-positive/HER2-negative metastatic breast cancer in the second- and third-line settings,” said lead author Aditya Bardia, MD, MPH, director of the breast cancer research program at Mass General Cancer Center and associate professor at Harvard Medical School, both in Boston. “Clinically, elacestrant has the potential to become the new standard of care in the study population.”
Endocrine therapy and CDK4/6 inhibitors remain the mainstay for the management of ER-positive/HER2 metastatic breast cancer. However, most patients will eventually develop resistance to these agents, often caused by the development of ESR1 mutations.
At the current time, fulvestrant is the only SERD available on the U.S. market, which means there is an urgent unmet need for new, effective SERDs in this setting, especially for patients harboring ESR1 mutations, Dr. Bardia explained.
In an early phase 1 trial, Dr. Bardia and his team evaluated elacestrant for safety and antitumor activity and found it had an acceptable safety profile and demonstrated single-agent activity with confirmed partial responses in heavily pretreated patients with ER-positive metastatic breast cancer.
This trial provided the rationale for investigating elacestrant in a phase 3 setting, Dr. Bardia said.
The multicenter, randomized, controlled phase 3 EMERALD trial included 477 postmenopausal women with ER-positive/HER2-negative metastatic breast cancer who had received one or two prior lines of endocrine therapy and no more than one line of chemotherapy in the metastatic setting. Patients had also progressed on prior treatment with a CDK4/6 inhibitor.
Patients were randomized to elacestrant 400 mg orally daily (n = 239) or standard of care (investigator’s choice of fulvestrant or an aromatase inhibitor, n = 238). The cohorts were further stratified by ESR1 mutation status, prior fulvestrant exposure, and presence of visceral disease.
The coprimary endpoints were progression-free survival in patients with tumors harboring ESR1 mutations and in the entire cohort. Secondary endpoints included overall survival, safety, tolerability, and quality of life.
“This was a positive study as it met both primary endpoints,” said Dr. Bardia.
The team found a 30% reduction in the risk of progression or death in the elacestrant arm for all patients (hazard ratio, 0.697; P = .0018) and a 45% (HR, 0.546; P =.0005) reduction in the risk of progression or death among those with ESR1 mutations.
At 12 months, the progression-free survival rate was 22.32% with elacestrant versus 9.42% for those receiving the standard of care. Among the ESR1 mutation group, those rates were slightly more pronounced: 26.76% with elacestrant versus 8.19% with standard of care.
Overall survival data were not yet mature but trended in favor of elacestrant in all patients (HR, 0.751; P = .0821) as well as those with ESR1 mutations (HR, 0.592; P = .0325). The final overall survival analysis is expected next year, Dr. Bardia said.
Common treatment-related adverse events with elacestrant versus standard of care included mostly grade 1 or 2 nausea (25.3% vs. 8.7%), vomiting (11% vs. 2.6%), and fatigue (11% vs. 7.9%). The rate of grade 3 or higher adverse events was 7.2% in the elacestrant arm versus 3.1% in the standard of care group and was mainly driven by nausea. Treatment-emergent adverse events leading to discontinuation of elacestrant or standard of care were infrequent in both arms (6.3% and 4.4%, respectively). No treatment-related deaths occurred in either group.
Dr. Bardia added that further studies are planned and assess the efficacy of elacestrant during earlier lines of treatment and in combination with other therapies, such as CDK4/6 inhibitors.
Weighing in on the recent findings, Carlos Arteaga, MD, who was not involved in the research, said this represents an important study evaluating a therapeutic priority.
“The data suggest that [elacestrant] may be a new option, not only as monotherapy but in combination with other therapies,” Dr. Arteaga, director of Simmons Comprehensive Cancer Center at the University of Texas Southwestern Medical Center, Dallas, and cochair of SABCS, said in an interview.
Coral Omene, MD, PhD, a medical oncologist at Rutgers Cancer Institute of New Jersey and assistant professor of medicine at Robert Wood Johnson Medical School, both in New Brunswick, also commented on the importance of the EMERALD results.
“I would think that this is practice changing,” said Dr. Omene, who was also not involved in the research. The new oral SERD “demonstrates a significant advantage in progression-free survival over either fulvestrant or an aromatase inhibitor.”
An oral drug could also potentially save patients from painful injections that can occasionally result in injection-site abscesses from long-term administration, she explained. “It’s also more convenient to take oral pills at home. It saves on transportation and omits waiting in treatment rooms for administrations.”
Although the overall survival data are not yet mature and the rate of adverse events was higher with elacestrant, “progression-free survival is a surrogate endpoint widely used for overall survival and is reasonable to consider a treatment regimen based on this while awaiting mature survival data,” Dr. Omene added. “The increase in nausea and vomiting seen in oral SERD arm is likely manageable, as there were no significant differences in discontinuation in both arms of treatment.”
The study was supported by Radius Health. Dr. Bardia has served as a consultant or on an advisory board for Radius Health, Pfizer, Novartis, Genentech, Merck, Immunomedics/Gilead, Sanofi, Daiichi Sankyo/AstraZeneca, Phillips, Eli Lilly, and Foundation Medicine. He has conducted contracted research or received grants from Genentech, Novartis, Pfizer, Merck, Sanofi, Radius Health, Immunomedics/Gilead, Daiichi Sankyo/AstraZeneca, Natera, and Eli Lilly.
A version of this article first appeared on Medscape.com.
Findings from the phase 3 EMERALD trial, presented at the San Antonio Breast Cancer Symposium, revealed that the effects of elacestrant (Menarini and Radius Health) were even more pronounced in women with ESR1 mutations. Women in the elacestrant arm had a 45% reduced risk of death or disease progression in comparison with those who received standard of care.
This new agent is the “first oral SERD to demonstrate a statistically significant and clinically meaningful improvement of progression-free survival in patients with ER-positive/HER2-negative metastatic breast cancer in the second- and third-line settings,” said lead author Aditya Bardia, MD, MPH, director of the breast cancer research program at Mass General Cancer Center and associate professor at Harvard Medical School, both in Boston. “Clinically, elacestrant has the potential to become the new standard of care in the study population.”
Endocrine therapy and CDK4/6 inhibitors remain the mainstay for the management of ER-positive/HER2 metastatic breast cancer. However, most patients will eventually develop resistance to these agents, often caused by the development of ESR1 mutations.
At the current time, fulvestrant is the only SERD available on the U.S. market, which means there is an urgent unmet need for new, effective SERDs in this setting, especially for patients harboring ESR1 mutations, Dr. Bardia explained.
In an early phase 1 trial, Dr. Bardia and his team evaluated elacestrant for safety and antitumor activity and found it had an acceptable safety profile and demonstrated single-agent activity with confirmed partial responses in heavily pretreated patients with ER-positive metastatic breast cancer.
This trial provided the rationale for investigating elacestrant in a phase 3 setting, Dr. Bardia said.
The multicenter, randomized, controlled phase 3 EMERALD trial included 477 postmenopausal women with ER-positive/HER2-negative metastatic breast cancer who had received one or two prior lines of endocrine therapy and no more than one line of chemotherapy in the metastatic setting. Patients had also progressed on prior treatment with a CDK4/6 inhibitor.
Patients were randomized to elacestrant 400 mg orally daily (n = 239) or standard of care (investigator’s choice of fulvestrant or an aromatase inhibitor, n = 238). The cohorts were further stratified by ESR1 mutation status, prior fulvestrant exposure, and presence of visceral disease.
The coprimary endpoints were progression-free survival in patients with tumors harboring ESR1 mutations and in the entire cohort. Secondary endpoints included overall survival, safety, tolerability, and quality of life.
“This was a positive study as it met both primary endpoints,” said Dr. Bardia.
The team found a 30% reduction in the risk of progression or death in the elacestrant arm for all patients (hazard ratio, 0.697; P = .0018) and a 45% (HR, 0.546; P =.0005) reduction in the risk of progression or death among those with ESR1 mutations.
At 12 months, the progression-free survival rate was 22.32% with elacestrant versus 9.42% for those receiving the standard of care. Among the ESR1 mutation group, those rates were slightly more pronounced: 26.76% with elacestrant versus 8.19% with standard of care.
Overall survival data were not yet mature but trended in favor of elacestrant in all patients (HR, 0.751; P = .0821) as well as those with ESR1 mutations (HR, 0.592; P = .0325). The final overall survival analysis is expected next year, Dr. Bardia said.
Common treatment-related adverse events with elacestrant versus standard of care included mostly grade 1 or 2 nausea (25.3% vs. 8.7%), vomiting (11% vs. 2.6%), and fatigue (11% vs. 7.9%). The rate of grade 3 or higher adverse events was 7.2% in the elacestrant arm versus 3.1% in the standard of care group and was mainly driven by nausea. Treatment-emergent adverse events leading to discontinuation of elacestrant or standard of care were infrequent in both arms (6.3% and 4.4%, respectively). No treatment-related deaths occurred in either group.
Dr. Bardia added that further studies are planned and assess the efficacy of elacestrant during earlier lines of treatment and in combination with other therapies, such as CDK4/6 inhibitors.
Weighing in on the recent findings, Carlos Arteaga, MD, who was not involved in the research, said this represents an important study evaluating a therapeutic priority.
“The data suggest that [elacestrant] may be a new option, not only as monotherapy but in combination with other therapies,” Dr. Arteaga, director of Simmons Comprehensive Cancer Center at the University of Texas Southwestern Medical Center, Dallas, and cochair of SABCS, said in an interview.
Coral Omene, MD, PhD, a medical oncologist at Rutgers Cancer Institute of New Jersey and assistant professor of medicine at Robert Wood Johnson Medical School, both in New Brunswick, also commented on the importance of the EMERALD results.
“I would think that this is practice changing,” said Dr. Omene, who was also not involved in the research. The new oral SERD “demonstrates a significant advantage in progression-free survival over either fulvestrant or an aromatase inhibitor.”
An oral drug could also potentially save patients from painful injections that can occasionally result in injection-site abscesses from long-term administration, she explained. “It’s also more convenient to take oral pills at home. It saves on transportation and omits waiting in treatment rooms for administrations.”
Although the overall survival data are not yet mature and the rate of adverse events was higher with elacestrant, “progression-free survival is a surrogate endpoint widely used for overall survival and is reasonable to consider a treatment regimen based on this while awaiting mature survival data,” Dr. Omene added. “The increase in nausea and vomiting seen in oral SERD arm is likely manageable, as there were no significant differences in discontinuation in both arms of treatment.”
The study was supported by Radius Health. Dr. Bardia has served as a consultant or on an advisory board for Radius Health, Pfizer, Novartis, Genentech, Merck, Immunomedics/Gilead, Sanofi, Daiichi Sankyo/AstraZeneca, Phillips, Eli Lilly, and Foundation Medicine. He has conducted contracted research or received grants from Genentech, Novartis, Pfizer, Merck, Sanofi, Radius Health, Immunomedics/Gilead, Daiichi Sankyo/AstraZeneca, Natera, and Eli Lilly.
A version of this article first appeared on Medscape.com.
FROM SABCS 2021
Black women most at risk for lymphedema after ALND
“Axillary lymph node dissection remains the main risk factor for the development of lymphedema,” Andrea Barrio, MD, associate attending physician, Memorial Sloan Kettering Cancer Center, New York, said at a virtual press briefing at the San Antonio Breast Cancer Symposium (SABCS) 2021.
“We observed a higher incidence of lymphedema in Black women treated with ALND and RT [radiotherapy] after adjustment for other variables,” Dr. Barrio added. “While the etiology for this increased incidence is largely unknown, future studies should address the biologic mechanisms behind racial disparities in lymphedema development.”
Dr. Barrio and colleagues included 276 patients in the analysis – 60% were White, 20% Black, 11% Asian, and 6% Hispanic. The remaining 3% did not report race or ethnicity. Patients’ median age at baseline was 48 years, and the median body mass index was 26.4 kg/m2. Slightly over-two thirds of participants had hormone receptor (HR)–positive/HER2-negative breast cancer.
All patients underwent unilateral ALND. About 70% received neoadjuvant chemotherapy (NAC), and the remainder had upfront surgery followed by adjuvant chemotherapy. Ninety-five percent of patients received radiotherapy, and almost all underwent nodal radiotherapy as well.
The median number of lymph nodes removed was 18, and the median number of positive lymph nodes was two. Using a perometer, arm volume was measured at baseline, postoperatively, and every 6 months for a total of 2 years. Lymphedema was defined as a relative increase in arm volume of greater than or equal to 10% from baseline.
At 24 months, almost 25% of the group had lymphedema, but the incidence differed significantly by race and ethnicity. The highest incidence was observed among Black women, at 39.4%, compared to 27.7% of Hispanic women, 23.4% of Asian women, and 20.5% of White women in the study.
The incidence of lymphedema also varied significantly by treatment group. The incidence was twofold greater among women treated with NAC in comparison with those who underwent upfront surgery (30.9% vs. 11.1%), Dr. Barrio noted.
On multivariate analysis, Black race was the strongest predictor of lymphedema. Compared to White women, Black women had a 3.5-fold greater risk of lymphedema. Hispanic women also had a threefold increased risk compared to White women, but Dr. Barrio cautioned that there were only 16 Hispanic patients in the study.
Older age and increasing time from surgery were also both modestly associated with an increased risk of lymphedema. Among women who ultimately developed lymphedema, “severity did not vary across race or ethnicity with similar relative volume changes observed,” Dr. Barrio said.
Given that the study found that NAC was an independent predictor of lymphedema, should alternatives to NAC be favored?
Although oncologists provide NAC for a variety of reasons, women with HR-positive/HER2-negative disease – which represent the majority of patients in the current analysis – are most likely to have residual disease after NAC, Dr. Barrio noted. This suggests that oncologists need to start looking at surgical de-escalation trials in this group of patients to help them avoid ALND.
Asked whether oncologists still underestimate the impact that lymphedema has on patients’ quality of life, Virginia Kaklamani, MD, professor of medicine, UT Health San Antonio MD Anderson Cancer Center, Texas, said the oncology community has come a long way.
“Any surgeon or medical oncologist will tell you that in the 1960s and 70s, women were having much higher rates of lymphedema than they are now, so this is something that we do recognize and we are a lot more careful about,” she told this news organization.
Surgical techniques are also better now, and the number of lymph nodes that are being removed is much reduced. Nevertheless, when physicians add ALND and radiation to the axilla, “rates of lymphedema go up,” Dr. Kaklamani acknowledged. “We need these women to have physical therapy before they develop lymphedema.”
Dr. Barrio agreed, adding that if oncologists could identify earlier thresholds for lymphedema, before patients develop arm swelling, “we may be able to intervene and see a reduction in its development.”
In the meantime, Dr. Barrio and colleagues are testing the protective value of offering immediate lymphatic reconstruction following ALND versus no reconstruction. In addition, they will be studying banked tissue from Black women to better understand any racial differences in inflammatory responses, the risk of fibrosis, and the reaction to radiotherapy.
“I think we see that inflammation is a key driver of lymphedema development, and so maybe Black women are predisposed to a different inflammatory reaction to treatment or perhaps have higher levels of inflammation at baseline,” Dr. Barrio speculated.
“I think it’s also important to stratify a woman’s risk for lymphedema, and once we can tailor that risk, we can start to identify which patients might benefit from preventative strategies,” she added.
Dr. Barrio has disclosed no relevant financial relationships. Dr. Kaklamani has served as a consultant for Puma, AstraZeneca, Athenex, and Immunomedics and as a speaker for Pfizer, Celgene, Genentech, Genomic Health, Puma, Eisai, Novartis, AstraZeneca, Daiichi Sankyo, and Seattle Genetics. She has also received research funding from Eisai.
A version of this article first appeared on Medscape.com.
“Axillary lymph node dissection remains the main risk factor for the development of lymphedema,” Andrea Barrio, MD, associate attending physician, Memorial Sloan Kettering Cancer Center, New York, said at a virtual press briefing at the San Antonio Breast Cancer Symposium (SABCS) 2021.
“We observed a higher incidence of lymphedema in Black women treated with ALND and RT [radiotherapy] after adjustment for other variables,” Dr. Barrio added. “While the etiology for this increased incidence is largely unknown, future studies should address the biologic mechanisms behind racial disparities in lymphedema development.”
Dr. Barrio and colleagues included 276 patients in the analysis – 60% were White, 20% Black, 11% Asian, and 6% Hispanic. The remaining 3% did not report race or ethnicity. Patients’ median age at baseline was 48 years, and the median body mass index was 26.4 kg/m2. Slightly over-two thirds of participants had hormone receptor (HR)–positive/HER2-negative breast cancer.
All patients underwent unilateral ALND. About 70% received neoadjuvant chemotherapy (NAC), and the remainder had upfront surgery followed by adjuvant chemotherapy. Ninety-five percent of patients received radiotherapy, and almost all underwent nodal radiotherapy as well.
The median number of lymph nodes removed was 18, and the median number of positive lymph nodes was two. Using a perometer, arm volume was measured at baseline, postoperatively, and every 6 months for a total of 2 years. Lymphedema was defined as a relative increase in arm volume of greater than or equal to 10% from baseline.
At 24 months, almost 25% of the group had lymphedema, but the incidence differed significantly by race and ethnicity. The highest incidence was observed among Black women, at 39.4%, compared to 27.7% of Hispanic women, 23.4% of Asian women, and 20.5% of White women in the study.
The incidence of lymphedema also varied significantly by treatment group. The incidence was twofold greater among women treated with NAC in comparison with those who underwent upfront surgery (30.9% vs. 11.1%), Dr. Barrio noted.
On multivariate analysis, Black race was the strongest predictor of lymphedema. Compared to White women, Black women had a 3.5-fold greater risk of lymphedema. Hispanic women also had a threefold increased risk compared to White women, but Dr. Barrio cautioned that there were only 16 Hispanic patients in the study.
Older age and increasing time from surgery were also both modestly associated with an increased risk of lymphedema. Among women who ultimately developed lymphedema, “severity did not vary across race or ethnicity with similar relative volume changes observed,” Dr. Barrio said.
Given that the study found that NAC was an independent predictor of lymphedema, should alternatives to NAC be favored?
Although oncologists provide NAC for a variety of reasons, women with HR-positive/HER2-negative disease – which represent the majority of patients in the current analysis – are most likely to have residual disease after NAC, Dr. Barrio noted. This suggests that oncologists need to start looking at surgical de-escalation trials in this group of patients to help them avoid ALND.
Asked whether oncologists still underestimate the impact that lymphedema has on patients’ quality of life, Virginia Kaklamani, MD, professor of medicine, UT Health San Antonio MD Anderson Cancer Center, Texas, said the oncology community has come a long way.
“Any surgeon or medical oncologist will tell you that in the 1960s and 70s, women were having much higher rates of lymphedema than they are now, so this is something that we do recognize and we are a lot more careful about,” she told this news organization.
Surgical techniques are also better now, and the number of lymph nodes that are being removed is much reduced. Nevertheless, when physicians add ALND and radiation to the axilla, “rates of lymphedema go up,” Dr. Kaklamani acknowledged. “We need these women to have physical therapy before they develop lymphedema.”
Dr. Barrio agreed, adding that if oncologists could identify earlier thresholds for lymphedema, before patients develop arm swelling, “we may be able to intervene and see a reduction in its development.”
In the meantime, Dr. Barrio and colleagues are testing the protective value of offering immediate lymphatic reconstruction following ALND versus no reconstruction. In addition, they will be studying banked tissue from Black women to better understand any racial differences in inflammatory responses, the risk of fibrosis, and the reaction to radiotherapy.
“I think we see that inflammation is a key driver of lymphedema development, and so maybe Black women are predisposed to a different inflammatory reaction to treatment or perhaps have higher levels of inflammation at baseline,” Dr. Barrio speculated.
“I think it’s also important to stratify a woman’s risk for lymphedema, and once we can tailor that risk, we can start to identify which patients might benefit from preventative strategies,” she added.
Dr. Barrio has disclosed no relevant financial relationships. Dr. Kaklamani has served as a consultant for Puma, AstraZeneca, Athenex, and Immunomedics and as a speaker for Pfizer, Celgene, Genentech, Genomic Health, Puma, Eisai, Novartis, AstraZeneca, Daiichi Sankyo, and Seattle Genetics. She has also received research funding from Eisai.
A version of this article first appeared on Medscape.com.
“Axillary lymph node dissection remains the main risk factor for the development of lymphedema,” Andrea Barrio, MD, associate attending physician, Memorial Sloan Kettering Cancer Center, New York, said at a virtual press briefing at the San Antonio Breast Cancer Symposium (SABCS) 2021.
“We observed a higher incidence of lymphedema in Black women treated with ALND and RT [radiotherapy] after adjustment for other variables,” Dr. Barrio added. “While the etiology for this increased incidence is largely unknown, future studies should address the biologic mechanisms behind racial disparities in lymphedema development.”
Dr. Barrio and colleagues included 276 patients in the analysis – 60% were White, 20% Black, 11% Asian, and 6% Hispanic. The remaining 3% did not report race or ethnicity. Patients’ median age at baseline was 48 years, and the median body mass index was 26.4 kg/m2. Slightly over-two thirds of participants had hormone receptor (HR)–positive/HER2-negative breast cancer.
All patients underwent unilateral ALND. About 70% received neoadjuvant chemotherapy (NAC), and the remainder had upfront surgery followed by adjuvant chemotherapy. Ninety-five percent of patients received radiotherapy, and almost all underwent nodal radiotherapy as well.
The median number of lymph nodes removed was 18, and the median number of positive lymph nodes was two. Using a perometer, arm volume was measured at baseline, postoperatively, and every 6 months for a total of 2 years. Lymphedema was defined as a relative increase in arm volume of greater than or equal to 10% from baseline.
At 24 months, almost 25% of the group had lymphedema, but the incidence differed significantly by race and ethnicity. The highest incidence was observed among Black women, at 39.4%, compared to 27.7% of Hispanic women, 23.4% of Asian women, and 20.5% of White women in the study.
The incidence of lymphedema also varied significantly by treatment group. The incidence was twofold greater among women treated with NAC in comparison with those who underwent upfront surgery (30.9% vs. 11.1%), Dr. Barrio noted.
On multivariate analysis, Black race was the strongest predictor of lymphedema. Compared to White women, Black women had a 3.5-fold greater risk of lymphedema. Hispanic women also had a threefold increased risk compared to White women, but Dr. Barrio cautioned that there were only 16 Hispanic patients in the study.
Older age and increasing time from surgery were also both modestly associated with an increased risk of lymphedema. Among women who ultimately developed lymphedema, “severity did not vary across race or ethnicity with similar relative volume changes observed,” Dr. Barrio said.
Given that the study found that NAC was an independent predictor of lymphedema, should alternatives to NAC be favored?
Although oncologists provide NAC for a variety of reasons, women with HR-positive/HER2-negative disease – which represent the majority of patients in the current analysis – are most likely to have residual disease after NAC, Dr. Barrio noted. This suggests that oncologists need to start looking at surgical de-escalation trials in this group of patients to help them avoid ALND.
Asked whether oncologists still underestimate the impact that lymphedema has on patients’ quality of life, Virginia Kaklamani, MD, professor of medicine, UT Health San Antonio MD Anderson Cancer Center, Texas, said the oncology community has come a long way.
“Any surgeon or medical oncologist will tell you that in the 1960s and 70s, women were having much higher rates of lymphedema than they are now, so this is something that we do recognize and we are a lot more careful about,” she told this news organization.
Surgical techniques are also better now, and the number of lymph nodes that are being removed is much reduced. Nevertheless, when physicians add ALND and radiation to the axilla, “rates of lymphedema go up,” Dr. Kaklamani acknowledged. “We need these women to have physical therapy before they develop lymphedema.”
Dr. Barrio agreed, adding that if oncologists could identify earlier thresholds for lymphedema, before patients develop arm swelling, “we may be able to intervene and see a reduction in its development.”
In the meantime, Dr. Barrio and colleagues are testing the protective value of offering immediate lymphatic reconstruction following ALND versus no reconstruction. In addition, they will be studying banked tissue from Black women to better understand any racial differences in inflammatory responses, the risk of fibrosis, and the reaction to radiotherapy.
“I think we see that inflammation is a key driver of lymphedema development, and so maybe Black women are predisposed to a different inflammatory reaction to treatment or perhaps have higher levels of inflammation at baseline,” Dr. Barrio speculated.
“I think it’s also important to stratify a woman’s risk for lymphedema, and once we can tailor that risk, we can start to identify which patients might benefit from preventative strategies,” she added.
Dr. Barrio has disclosed no relevant financial relationships. Dr. Kaklamani has served as a consultant for Puma, AstraZeneca, Athenex, and Immunomedics and as a speaker for Pfizer, Celgene, Genentech, Genomic Health, Puma, Eisai, Novartis, AstraZeneca, Daiichi Sankyo, and Seattle Genetics. She has also received research funding from Eisai.
A version of this article first appeared on Medscape.com.
In metastatic breast cancer, primary resections on the decline
Retrospective studies have suggested a possible benefit to resection, according to Sasha Douglas, MD, who presented the study (abstract PD7-06) at the 2021 San Antonio Breast Cancer Symposium. “Intuitively, you would think that you would want to get the primary tumor out even if it’s metastasized, so that it couldn’t metastasize more,” said Dr. Douglas, who is a surgical resident at the University of California, San Diego.
However, clinical trials have yielded mixed results, and the picture is complicated by the various molecular subtypes of breast cancer, metastatic sites, and other factors. “Different studies, whether it’s retrospective, and a really large database that has lots of numbers of patients, can give you a different answer than a smaller prospective randomized, controlled study in a different cohort of patients. So, we just thought it would be really interesting to look at all the trends over time at Commission on Cancer–accredited hospitals. Do they seem to be following what the latest literature is showing?” Dr. Douglas said in an interview.
The researchers used data from 87,331 cases from the National Cancer Database (NCDB) and examined rates of primary surgery as well as palliative care in women with metastatic breast cancer who had responded well to systemic therapy.
Between 2004 and 2009, the frequency of primary tumor resection remained near 35% (with a peak of 37% in 2009), then began a steady descent to 18% by 2017. The researchers found similar trends in estrogen receptor–positive/progesterone receptor–positive, HER2-negative (ER/PR+HERer2–); HER2-positive; and triple-negative subtypes.
In 2004, 48% of patients received only systemic therapy, while 37% received some combination of surgery and radiation to the primary tumor. By 2019, 69% received only systemic therapy and 20% received locoregional therapy (P < .001). “It seems that surgeons and providers and medical oncologists are becoming more selective about who they’re going to offer surgery to, and I think that’s very appropriate,” said Dr. Douglas.
But another finding suggests room for improvement: Just 21% of patients received palliative care. “I think that everybody with a major systemic illness like this would benefit from palliative care, just on a supportive basis. The palliative care team can really help people with quality of life, but I think it still has that stigma, and I think that’s what we’ve seen from our study,” said Dr. Douglas.
“We’re just postulating, [but] a lot of that could be from the stigma of thinking that palliative care means giving up. It doesn’t necessarily mean that. It means you’re dealing with a difficult chronic illness, and [palliative care] can be very, very helpful for patients,” said Dr. Douglas.
The study is limited by its retrospective nature, and palliative care might be underreported in the NCDB.
The study was funded by the National Cancer Institute and the University of California, San Diego. Dr. Douglas has no financial disclosures.
Retrospective studies have suggested a possible benefit to resection, according to Sasha Douglas, MD, who presented the study (abstract PD7-06) at the 2021 San Antonio Breast Cancer Symposium. “Intuitively, you would think that you would want to get the primary tumor out even if it’s metastasized, so that it couldn’t metastasize more,” said Dr. Douglas, who is a surgical resident at the University of California, San Diego.
However, clinical trials have yielded mixed results, and the picture is complicated by the various molecular subtypes of breast cancer, metastatic sites, and other factors. “Different studies, whether it’s retrospective, and a really large database that has lots of numbers of patients, can give you a different answer than a smaller prospective randomized, controlled study in a different cohort of patients. So, we just thought it would be really interesting to look at all the trends over time at Commission on Cancer–accredited hospitals. Do they seem to be following what the latest literature is showing?” Dr. Douglas said in an interview.
The researchers used data from 87,331 cases from the National Cancer Database (NCDB) and examined rates of primary surgery as well as palliative care in women with metastatic breast cancer who had responded well to systemic therapy.
Between 2004 and 2009, the frequency of primary tumor resection remained near 35% (with a peak of 37% in 2009), then began a steady descent to 18% by 2017. The researchers found similar trends in estrogen receptor–positive/progesterone receptor–positive, HER2-negative (ER/PR+HERer2–); HER2-positive; and triple-negative subtypes.
In 2004, 48% of patients received only systemic therapy, while 37% received some combination of surgery and radiation to the primary tumor. By 2019, 69% received only systemic therapy and 20% received locoregional therapy (P < .001). “It seems that surgeons and providers and medical oncologists are becoming more selective about who they’re going to offer surgery to, and I think that’s very appropriate,” said Dr. Douglas.
But another finding suggests room for improvement: Just 21% of patients received palliative care. “I think that everybody with a major systemic illness like this would benefit from palliative care, just on a supportive basis. The palliative care team can really help people with quality of life, but I think it still has that stigma, and I think that’s what we’ve seen from our study,” said Dr. Douglas.
“We’re just postulating, [but] a lot of that could be from the stigma of thinking that palliative care means giving up. It doesn’t necessarily mean that. It means you’re dealing with a difficult chronic illness, and [palliative care] can be very, very helpful for patients,” said Dr. Douglas.
The study is limited by its retrospective nature, and palliative care might be underreported in the NCDB.
The study was funded by the National Cancer Institute and the University of California, San Diego. Dr. Douglas has no financial disclosures.
Retrospective studies have suggested a possible benefit to resection, according to Sasha Douglas, MD, who presented the study (abstract PD7-06) at the 2021 San Antonio Breast Cancer Symposium. “Intuitively, you would think that you would want to get the primary tumor out even if it’s metastasized, so that it couldn’t metastasize more,” said Dr. Douglas, who is a surgical resident at the University of California, San Diego.
However, clinical trials have yielded mixed results, and the picture is complicated by the various molecular subtypes of breast cancer, metastatic sites, and other factors. “Different studies, whether it’s retrospective, and a really large database that has lots of numbers of patients, can give you a different answer than a smaller prospective randomized, controlled study in a different cohort of patients. So, we just thought it would be really interesting to look at all the trends over time at Commission on Cancer–accredited hospitals. Do they seem to be following what the latest literature is showing?” Dr. Douglas said in an interview.
The researchers used data from 87,331 cases from the National Cancer Database (NCDB) and examined rates of primary surgery as well as palliative care in women with metastatic breast cancer who had responded well to systemic therapy.
Between 2004 and 2009, the frequency of primary tumor resection remained near 35% (with a peak of 37% in 2009), then began a steady descent to 18% by 2017. The researchers found similar trends in estrogen receptor–positive/progesterone receptor–positive, HER2-negative (ER/PR+HERer2–); HER2-positive; and triple-negative subtypes.
In 2004, 48% of patients received only systemic therapy, while 37% received some combination of surgery and radiation to the primary tumor. By 2019, 69% received only systemic therapy and 20% received locoregional therapy (P < .001). “It seems that surgeons and providers and medical oncologists are becoming more selective about who they’re going to offer surgery to, and I think that’s very appropriate,” said Dr. Douglas.
But another finding suggests room for improvement: Just 21% of patients received palliative care. “I think that everybody with a major systemic illness like this would benefit from palliative care, just on a supportive basis. The palliative care team can really help people with quality of life, but I think it still has that stigma, and I think that’s what we’ve seen from our study,” said Dr. Douglas.
“We’re just postulating, [but] a lot of that could be from the stigma of thinking that palliative care means giving up. It doesn’t necessarily mean that. It means you’re dealing with a difficult chronic illness, and [palliative care] can be very, very helpful for patients,” said Dr. Douglas.
The study is limited by its retrospective nature, and palliative care might be underreported in the NCDB.
The study was funded by the National Cancer Institute and the University of California, San Diego. Dr. Douglas has no financial disclosures.
FROM SABCS 2021
What’s hot at the world’s premiere breast cancer meeting
Dr. Arteaga, the meeting’s codirector, said the first-ever hybrid symposium will take place virtually from Dec. 7 to 10 as well as in person. Online availability appears to be a boon to attendance, with a record 9,325 registrants for the 2020 symposium, held only virtually because of the COVID-19 pandemic.
The meeting will have an app available, which can be accessed by searching “San Antonio Breast Cancer Symposium” (Google Play for Android, Apple for iOS) and downloading, or by going to www.core-apps.com/dl/sabcs from a desktop computer.
Dr. Arteaga provided a sneak peek of the most exciting research being presented at the upcoming meeting.
On the horizon for advanced breast cancer
A “very important” study of an investigational oral agent employed in heavily pretreated postmenopausal women with estrogen receptor–positive (ER+) advanced breast cancer headlines the meeting.
This international, multicenter trial could have “practice-changing implications,” Dr. Arteaga said in an interview.
The phase 3 EMERALD trial (abstract GS2-02) pits elacestrant, a selective estrogen receptor degrader (SERD), against standard endocrine therapy (fulvestrant or an aromatase inhibitor) in patients with metastatic breast cancer whose disease has progressed after treatment with at least one endocrine therapy and a CDK4/6 inhibitor.
The trial is important because many patients with breast cancer have estrogen receptor mutations, which are a “major mechanism of [drug] resistance” and thus progression on earlier therapy, Dr. Arteaga said.
Elacestrant is in good company among a plethora of oral SERDs under investigation in advanced breast cancer; however, currently, fulvestrant – which requires an intramuscular injection in the buttocks every month – is the only approved SERD.
“There’s plenty of preclinical data that suggest that these drugs [SERDs] may have activity against these mutant forms of the receptor, which occur in up to 40% of patients with advanced ER+ breast cancer,” he explained.
Researchers will present data on two primary outcome measures from the phase 3 trial: progression-free survival (PFS) based on mutations of the estrogen receptor 1 gene (ESR1-mut) and PFS in all subjects regardless of ESR1 status.
In addition to the EMERALD trial, PADA-1 (abstract GS3-05) is another important randomized, phase 3 trial focused on treating estrogen receptor mutations in patients with metastatic disease, said Dr. Arteaga.
The trial has enrolled patients with ER+ metastatic breast cancer who received an aromatase inhibitor (letrozole, anastrozole, or exemestane) and the CDK4/6 inhibitor palbociclib as first-line therapy.
In step 1 of the trial, approximately 1,000 patients were screened for circulating blood ESR1 mutation detection at regular intervals while being treated with palbociclib and an aromatase inhibitor in a continuous scheme until tumor progression or ESR1 mutation detection.
In step 2, up to 200 patients with a rising circulating ESR1 mutation and no tumor progression were randomized 1:1 to no change in therapy until tumor progression or to receive palbociclib plus fulvestrant until tumor progression.
The trial examines the safety and efficacy of “a clinical conundrum that we face” in this setting: whether or not to switch treatment from an aromatase inhibitor to fulvestrant while continuing a CDK4/6 inhibitor at the sign of mutation detection, Dr. Arteaga explained.
Refining who gets the ‘kitchen sink’
Dr. Arteaga highlighted two trials focused on the immune checkpoint inhibitor pembrolizumab.
The phase 3 KEYNOTE-522 study led to the approval of neoadjuvant pembrolizumab plus chemotherapy for early-stage triple-negative breast cancer (TNBC) in July 2021. At this year’s SABCS, researchers will present new data from KEYNOTE-522 (abstract GS1-01), representing final results from the trial’s event-free survival (EFS) outcome.
Previously, investigators reported a statistically significant and clinically meaningful improvement in EFS. These data suggest “that deploying immunotherapy early before surgery ... may be curative in some patients,” Dr. Arteaga said. The new data will allow the “robustness and consistency” of the earlier findings to be assessed.
But, he added, this is a “tough” treatment, which includes five drugs. “It’s the kitchen sink, and not everybody needs the kitchen sink. It’s important to refine these findings. Some patients may not need pembrolizumab, but some do.”
The second trial exploring pembrolizumab – KEYNOTE-355 (abstract GS1-02) – mirrors KEYNOTE-522 but in patients with previously untreated locally recurrent inoperable or metastatic TNBC whose tumors expressed PD-L1.
Previously, investigators reported that pembrolizumab combined with chemotherapy showed statistically significant improvements in overall survival and PFS compared to placebo plus chemotherapy. At the 2021 SABCS, researchers will provide final study results, including outcomes in subgroups of patients by additional combined positive score cutoffs.
Metformin trial: ‘This is it’
Dr. Arteaga highlighted CCTGMA.32 (abstract GS1-08), a phase 3 randomized, placebo-controlled adjuvant trial of the diabetes drug metformin versus placebo in early breast cancer. Results of the primary efficacy analysis of the trial will be presented at the meeting.
The Canadian-led study seeks to determine if metformin can decrease breast cancer cell growth and work with cancer therapies to prevent disease recurrence. The study design calls for patients to take twice-daily oral metformin or placebo pills for up to 5 years in the absence of disease progression.
The primary outcome of the 3,500-plus patient trial is invasive disease-free survival in hormone receptor (ER and PgR) negative and positive (ER and/or PgR) subgroups.
“Metformin has actually been associated with improved survival [in breast cancer] in patients on chemotherapy. But we don’t know exactly how,” he said. “There’s never been a head-to-head comparison in the adjuvant setting [before]. This is it.”
TKI for breast cancer with brain mets
The SABCS codirector spotlighted an updated overall survival analysis of the randomized phase 3 PHOEBE trial (abstract GS3-02).
Previous research confirmed the superiority of pyrotinib, a novel TKI targeting HER1, HER2, and HER4, over lapatinib when given in combination with capecitabine in HER2-positive metastatic breast cancer.
In the United States, the lapatinib-capecitabine combination is “mostly used” in patients with HER2 metastatic disease and brain metastases who also undergo stereotactic radiation, Dr. Arteaga said.
This use has continued despite groundbreaking results from the HER2CLIMB trial, featuring the TKI tucatinib, he said.
As reported last year, adding tucatinib to trastuzumab and capecitabine in patients with HER2-positive breast cancer and brain metastases increased median overall survival from 12 months to 18.1 months. The results were called the first of their kind at that time.
The pyrotinib study may matter to American clinicians because pyrotinib is used mostly in China, not the United States, and this analysis suggests that pyrotinib could be part of the armamentarium in the United States, alongside tucatinib.
TKIs are like Coke and Pepsi, Dr. Arteaga said: “Similar but not identical.” Therefore, it is worth taking a look at the new study, he said. “There may be some benefit in having more than one [TKI] in the therapeutic armamentarium.”
Dr. Arteaga receives or has received grant support from Pfizer and Lilly and serves or has served in a scientific advisory role with Novartis, Lilly, TAIHO Oncology, Daiichi Sankyo, Merck, AstraZeneca, OrigiMed, Immunomedics, ARVINAS, Sanofi, Athenex, and the Susan G. Komen Foundation. He also holds minor stock options from Provista.
A version of this article first appeared on Medscape.com.
Dr. Arteaga, the meeting’s codirector, said the first-ever hybrid symposium will take place virtually from Dec. 7 to 10 as well as in person. Online availability appears to be a boon to attendance, with a record 9,325 registrants for the 2020 symposium, held only virtually because of the COVID-19 pandemic.
The meeting will have an app available, which can be accessed by searching “San Antonio Breast Cancer Symposium” (Google Play for Android, Apple for iOS) and downloading, or by going to www.core-apps.com/dl/sabcs from a desktop computer.
Dr. Arteaga provided a sneak peek of the most exciting research being presented at the upcoming meeting.
On the horizon for advanced breast cancer
A “very important” study of an investigational oral agent employed in heavily pretreated postmenopausal women with estrogen receptor–positive (ER+) advanced breast cancer headlines the meeting.
This international, multicenter trial could have “practice-changing implications,” Dr. Arteaga said in an interview.
The phase 3 EMERALD trial (abstract GS2-02) pits elacestrant, a selective estrogen receptor degrader (SERD), against standard endocrine therapy (fulvestrant or an aromatase inhibitor) in patients with metastatic breast cancer whose disease has progressed after treatment with at least one endocrine therapy and a CDK4/6 inhibitor.
The trial is important because many patients with breast cancer have estrogen receptor mutations, which are a “major mechanism of [drug] resistance” and thus progression on earlier therapy, Dr. Arteaga said.
Elacestrant is in good company among a plethora of oral SERDs under investigation in advanced breast cancer; however, currently, fulvestrant – which requires an intramuscular injection in the buttocks every month – is the only approved SERD.
“There’s plenty of preclinical data that suggest that these drugs [SERDs] may have activity against these mutant forms of the receptor, which occur in up to 40% of patients with advanced ER+ breast cancer,” he explained.
Researchers will present data on two primary outcome measures from the phase 3 trial: progression-free survival (PFS) based on mutations of the estrogen receptor 1 gene (ESR1-mut) and PFS in all subjects regardless of ESR1 status.
In addition to the EMERALD trial, PADA-1 (abstract GS3-05) is another important randomized, phase 3 trial focused on treating estrogen receptor mutations in patients with metastatic disease, said Dr. Arteaga.
The trial has enrolled patients with ER+ metastatic breast cancer who received an aromatase inhibitor (letrozole, anastrozole, or exemestane) and the CDK4/6 inhibitor palbociclib as first-line therapy.
In step 1 of the trial, approximately 1,000 patients were screened for circulating blood ESR1 mutation detection at regular intervals while being treated with palbociclib and an aromatase inhibitor in a continuous scheme until tumor progression or ESR1 mutation detection.
In step 2, up to 200 patients with a rising circulating ESR1 mutation and no tumor progression were randomized 1:1 to no change in therapy until tumor progression or to receive palbociclib plus fulvestrant until tumor progression.
The trial examines the safety and efficacy of “a clinical conundrum that we face” in this setting: whether or not to switch treatment from an aromatase inhibitor to fulvestrant while continuing a CDK4/6 inhibitor at the sign of mutation detection, Dr. Arteaga explained.
Refining who gets the ‘kitchen sink’
Dr. Arteaga highlighted two trials focused on the immune checkpoint inhibitor pembrolizumab.
The phase 3 KEYNOTE-522 study led to the approval of neoadjuvant pembrolizumab plus chemotherapy for early-stage triple-negative breast cancer (TNBC) in July 2021. At this year’s SABCS, researchers will present new data from KEYNOTE-522 (abstract GS1-01), representing final results from the trial’s event-free survival (EFS) outcome.
Previously, investigators reported a statistically significant and clinically meaningful improvement in EFS. These data suggest “that deploying immunotherapy early before surgery ... may be curative in some patients,” Dr. Arteaga said. The new data will allow the “robustness and consistency” of the earlier findings to be assessed.
But, he added, this is a “tough” treatment, which includes five drugs. “It’s the kitchen sink, and not everybody needs the kitchen sink. It’s important to refine these findings. Some patients may not need pembrolizumab, but some do.”
The second trial exploring pembrolizumab – KEYNOTE-355 (abstract GS1-02) – mirrors KEYNOTE-522 but in patients with previously untreated locally recurrent inoperable or metastatic TNBC whose tumors expressed PD-L1.
Previously, investigators reported that pembrolizumab combined with chemotherapy showed statistically significant improvements in overall survival and PFS compared to placebo plus chemotherapy. At the 2021 SABCS, researchers will provide final study results, including outcomes in subgroups of patients by additional combined positive score cutoffs.
Metformin trial: ‘This is it’
Dr. Arteaga highlighted CCTGMA.32 (abstract GS1-08), a phase 3 randomized, placebo-controlled adjuvant trial of the diabetes drug metformin versus placebo in early breast cancer. Results of the primary efficacy analysis of the trial will be presented at the meeting.
The Canadian-led study seeks to determine if metformin can decrease breast cancer cell growth and work with cancer therapies to prevent disease recurrence. The study design calls for patients to take twice-daily oral metformin or placebo pills for up to 5 years in the absence of disease progression.
The primary outcome of the 3,500-plus patient trial is invasive disease-free survival in hormone receptor (ER and PgR) negative and positive (ER and/or PgR) subgroups.
“Metformin has actually been associated with improved survival [in breast cancer] in patients on chemotherapy. But we don’t know exactly how,” he said. “There’s never been a head-to-head comparison in the adjuvant setting [before]. This is it.”
TKI for breast cancer with brain mets
The SABCS codirector spotlighted an updated overall survival analysis of the randomized phase 3 PHOEBE trial (abstract GS3-02).
Previous research confirmed the superiority of pyrotinib, a novel TKI targeting HER1, HER2, and HER4, over lapatinib when given in combination with capecitabine in HER2-positive metastatic breast cancer.
In the United States, the lapatinib-capecitabine combination is “mostly used” in patients with HER2 metastatic disease and brain metastases who also undergo stereotactic radiation, Dr. Arteaga said.
This use has continued despite groundbreaking results from the HER2CLIMB trial, featuring the TKI tucatinib, he said.
As reported last year, adding tucatinib to trastuzumab and capecitabine in patients with HER2-positive breast cancer and brain metastases increased median overall survival from 12 months to 18.1 months. The results were called the first of their kind at that time.
The pyrotinib study may matter to American clinicians because pyrotinib is used mostly in China, not the United States, and this analysis suggests that pyrotinib could be part of the armamentarium in the United States, alongside tucatinib.
TKIs are like Coke and Pepsi, Dr. Arteaga said: “Similar but not identical.” Therefore, it is worth taking a look at the new study, he said. “There may be some benefit in having more than one [TKI] in the therapeutic armamentarium.”
Dr. Arteaga receives or has received grant support from Pfizer and Lilly and serves or has served in a scientific advisory role with Novartis, Lilly, TAIHO Oncology, Daiichi Sankyo, Merck, AstraZeneca, OrigiMed, Immunomedics, ARVINAS, Sanofi, Athenex, and the Susan G. Komen Foundation. He also holds minor stock options from Provista.
A version of this article first appeared on Medscape.com.
Dr. Arteaga, the meeting’s codirector, said the first-ever hybrid symposium will take place virtually from Dec. 7 to 10 as well as in person. Online availability appears to be a boon to attendance, with a record 9,325 registrants for the 2020 symposium, held only virtually because of the COVID-19 pandemic.
The meeting will have an app available, which can be accessed by searching “San Antonio Breast Cancer Symposium” (Google Play for Android, Apple for iOS) and downloading, or by going to www.core-apps.com/dl/sabcs from a desktop computer.
Dr. Arteaga provided a sneak peek of the most exciting research being presented at the upcoming meeting.
On the horizon for advanced breast cancer
A “very important” study of an investigational oral agent employed in heavily pretreated postmenopausal women with estrogen receptor–positive (ER+) advanced breast cancer headlines the meeting.
This international, multicenter trial could have “practice-changing implications,” Dr. Arteaga said in an interview.
The phase 3 EMERALD trial (abstract GS2-02) pits elacestrant, a selective estrogen receptor degrader (SERD), against standard endocrine therapy (fulvestrant or an aromatase inhibitor) in patients with metastatic breast cancer whose disease has progressed after treatment with at least one endocrine therapy and a CDK4/6 inhibitor.
The trial is important because many patients with breast cancer have estrogen receptor mutations, which are a “major mechanism of [drug] resistance” and thus progression on earlier therapy, Dr. Arteaga said.
Elacestrant is in good company among a plethora of oral SERDs under investigation in advanced breast cancer; however, currently, fulvestrant – which requires an intramuscular injection in the buttocks every month – is the only approved SERD.
“There’s plenty of preclinical data that suggest that these drugs [SERDs] may have activity against these mutant forms of the receptor, which occur in up to 40% of patients with advanced ER+ breast cancer,” he explained.
Researchers will present data on two primary outcome measures from the phase 3 trial: progression-free survival (PFS) based on mutations of the estrogen receptor 1 gene (ESR1-mut) and PFS in all subjects regardless of ESR1 status.
In addition to the EMERALD trial, PADA-1 (abstract GS3-05) is another important randomized, phase 3 trial focused on treating estrogen receptor mutations in patients with metastatic disease, said Dr. Arteaga.
The trial has enrolled patients with ER+ metastatic breast cancer who received an aromatase inhibitor (letrozole, anastrozole, or exemestane) and the CDK4/6 inhibitor palbociclib as first-line therapy.
In step 1 of the trial, approximately 1,000 patients were screened for circulating blood ESR1 mutation detection at regular intervals while being treated with palbociclib and an aromatase inhibitor in a continuous scheme until tumor progression or ESR1 mutation detection.
In step 2, up to 200 patients with a rising circulating ESR1 mutation and no tumor progression were randomized 1:1 to no change in therapy until tumor progression or to receive palbociclib plus fulvestrant until tumor progression.
The trial examines the safety and efficacy of “a clinical conundrum that we face” in this setting: whether or not to switch treatment from an aromatase inhibitor to fulvestrant while continuing a CDK4/6 inhibitor at the sign of mutation detection, Dr. Arteaga explained.
Refining who gets the ‘kitchen sink’
Dr. Arteaga highlighted two trials focused on the immune checkpoint inhibitor pembrolizumab.
The phase 3 KEYNOTE-522 study led to the approval of neoadjuvant pembrolizumab plus chemotherapy for early-stage triple-negative breast cancer (TNBC) in July 2021. At this year’s SABCS, researchers will present new data from KEYNOTE-522 (abstract GS1-01), representing final results from the trial’s event-free survival (EFS) outcome.
Previously, investigators reported a statistically significant and clinically meaningful improvement in EFS. These data suggest “that deploying immunotherapy early before surgery ... may be curative in some patients,” Dr. Arteaga said. The new data will allow the “robustness and consistency” of the earlier findings to be assessed.
But, he added, this is a “tough” treatment, which includes five drugs. “It’s the kitchen sink, and not everybody needs the kitchen sink. It’s important to refine these findings. Some patients may not need pembrolizumab, but some do.”
The second trial exploring pembrolizumab – KEYNOTE-355 (abstract GS1-02) – mirrors KEYNOTE-522 but in patients with previously untreated locally recurrent inoperable or metastatic TNBC whose tumors expressed PD-L1.
Previously, investigators reported that pembrolizumab combined with chemotherapy showed statistically significant improvements in overall survival and PFS compared to placebo plus chemotherapy. At the 2021 SABCS, researchers will provide final study results, including outcomes in subgroups of patients by additional combined positive score cutoffs.
Metformin trial: ‘This is it’
Dr. Arteaga highlighted CCTGMA.32 (abstract GS1-08), a phase 3 randomized, placebo-controlled adjuvant trial of the diabetes drug metformin versus placebo in early breast cancer. Results of the primary efficacy analysis of the trial will be presented at the meeting.
The Canadian-led study seeks to determine if metformin can decrease breast cancer cell growth and work with cancer therapies to prevent disease recurrence. The study design calls for patients to take twice-daily oral metformin or placebo pills for up to 5 years in the absence of disease progression.
The primary outcome of the 3,500-plus patient trial is invasive disease-free survival in hormone receptor (ER and PgR) negative and positive (ER and/or PgR) subgroups.
“Metformin has actually been associated with improved survival [in breast cancer] in patients on chemotherapy. But we don’t know exactly how,” he said. “There’s never been a head-to-head comparison in the adjuvant setting [before]. This is it.”
TKI for breast cancer with brain mets
The SABCS codirector spotlighted an updated overall survival analysis of the randomized phase 3 PHOEBE trial (abstract GS3-02).
Previous research confirmed the superiority of pyrotinib, a novel TKI targeting HER1, HER2, and HER4, over lapatinib when given in combination with capecitabine in HER2-positive metastatic breast cancer.
In the United States, the lapatinib-capecitabine combination is “mostly used” in patients with HER2 metastatic disease and brain metastases who also undergo stereotactic radiation, Dr. Arteaga said.
This use has continued despite groundbreaking results from the HER2CLIMB trial, featuring the TKI tucatinib, he said.
As reported last year, adding tucatinib to trastuzumab and capecitabine in patients with HER2-positive breast cancer and brain metastases increased median overall survival from 12 months to 18.1 months. The results were called the first of their kind at that time.
The pyrotinib study may matter to American clinicians because pyrotinib is used mostly in China, not the United States, and this analysis suggests that pyrotinib could be part of the armamentarium in the United States, alongside tucatinib.
TKIs are like Coke and Pepsi, Dr. Arteaga said: “Similar but not identical.” Therefore, it is worth taking a look at the new study, he said. “There may be some benefit in having more than one [TKI] in the therapeutic armamentarium.”
Dr. Arteaga receives or has received grant support from Pfizer and Lilly and serves or has served in a scientific advisory role with Novartis, Lilly, TAIHO Oncology, Daiichi Sankyo, Merck, AstraZeneca, OrigiMed, Immunomedics, ARVINAS, Sanofi, Athenex, and the Susan G. Komen Foundation. He also holds minor stock options from Provista.
A version of this article first appeared on Medscape.com.
FROM SABCS 2021