TBD Meeting (5163-21)

Although rates are generally low, interstitial lung disease (ILD) can occur at any point in the first year of treatment with trastuzumab deruxtecan (T-DXd) for HER2-positive metastatic breast cancer (MBC).

That’s according to a pooled analysis of three early clinical trials with the drug that was reported at the European Society for Medical Oncology (ESMO): Breast Cancer virtual meeting.

Over a 5-year analysis period, the rate of any grade of ILD was 15.5%. The majority (79%) of those events were grade 1 or 2, observed pulmonologist Charles A. Powell, MD, of Icahn School of Medicine at Mount Sinai in New York, who presented the findings.

Of the 245 patients who were included in the analysis, 38 had an ILD event deemed related to treatment. A respective 9 (3.7%) and 21 (8.6%) had events graded as 1 or 2, 1 patient each (0.4%) had a grade 3 or 4 event, and 6 (2.4%) patients had a grade 5 event.

The timing of the first identified ILD event varied from 1.1 months to 20.8 months, given a median of 5.6 months overall. “This highlights an opportunity for more timely detection of ILD,” Dr. Powell suggested. He added that in almost all (97%) cases, ILD occurred before 12 months and the risk may even decrease over time “suggesting that the risk is not cumulative.”

He cautioned, however: “It is important to note that this analysis is exploratory and hypothesis generating in nature.”
 

ILD occurs with other cancer drugs

ILD is not just associated with T-DXd treatment, said the invited discussant for the trial, Harold J. Burstein, MD, PhD, of the Dana-Farber Cancer Institute in Boston.

“It’s important for clinicians to remember that ILD/pneumonitis is an uncommon, but potentially very serious side effect that affects many breast cancer treatments,” he said.

That not only includes T-DXd, but other newer drugs such the cyclin dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors, as well as other older more established drugs including taxanes, cyclophosphamide and even the mTOR inhibitor everolimus.

“Both clinicians and patients need to be aware of this risk. It’s part of the differential diagnosis for any patient who develops either ground glass changes or other infiltrates on a CT scan, or who has symptoms,” Dr. Burstein added.
 

Investigating ILD in T-DXd trials

T-DXd (Enhertu) is an anti-HER2-antibody drug conjugate that contains a humanized anti-HER2 IgG1 monoclonal antibody akin to trastuzumab that is linked to DXd, a topoisomerase I inhibitor that is a derivative of exatecan.

It has been approved for use in patients with HER2-positive metastatic breast cancer after two other HER2 treatments fail in the United States and Europe, and after chemotherapy in Japan, noted Dr. Powell. This is largely due to the results from the phase 2, open-label DESTINY-Breast01 trial.

“In breast cancer, T-DXd continues to demonstrate clinically meaningful efficacy with a median duration of response of more than 20 months in a heavily pretreated population,” he said. Objective response rates seen in the DESTINY-Breast01 trial were around 60%, and the median progression-free survival was a little over 19 months.

To look at the issue of drug-related ILD events in patients treated with T-DXd for HER2-positive MBC, an independent adjudication committee was formed to look at all the imaging and clinical data from the DESTINY-Breast01 trial and two single-arm phase 1 trials (NCT02564900 and NCT03383692).

In all, data on 245 patients who had been treated with T-DXd at the approved dose of 5.4 mg/kg in those trials between August 2015 and June 2020 were analyzed.
 

Dealing with lung toxicity

“We are getting new drugs to improve the treatment of cancer, but they always come with a price in terms of toxicity,” observed David Cameron, MD, professor of medical oncology at Edinburgh University in Scotland. Dr. Cameron chaired the session.

“Several measures were taken to identify and mitigate ILD,” across all the T-DXd studies, Dr. Powell explained. As well as the independent adjudication committee, available guidelines were followed and updated on how to diagnose and treat drug-induced lung injuries, and a “safe use” campaign was run in 2019.

Many patients in the early MBC studies were recruited before these measures were in place, such as the use of systemic steroids to manage low-grade events.

The bottom line, however, is that if a patient develops ILD then treatment should be stopped, Dr. Powell said. “Patients with grade 1 events may restart once the ILD has resolved, but those with grade 2 to 4 events must discontinue treatment.”

Dr. Powell concluded: “The overall clinical data support the positive risk-benefit profile of T-DXd. Phase 3 randomized controlled trials in breast cancer are ongoing.”
 

ILD also seen in monarchE trial with abemaciclib

Data on ILD events seen in the phase 3 monarchE trial were also reported separately at the ESMO Breast Cancer virtual meeting. The analysis population included 2,971 patients who had been treated with the CDK 4/6 inhibitor abemaciclib (Verzenio) together with endocrine therapy and 2,800 who had received endocrine therapy alone in the early-stage, adjuvant advanced breast cancer setting.

Most ILD (97%) events that occurred were single occurrences, with any grade of ILD occurring in a higher percentage of patients treated with abemaciclib with endocrine therapy than endocrine therapy alone (2.9% vs. 1.2%). Grade 3 events occurred in a respective 0.4% and 0.0% of patients.
 

So who’s at risk?

The risk factors for ILD and pneumonitis are not well characterized with either of the two drugs discussed, Dr. Burstein observed.

“In the abemaciclib experience, it looked like obesity might be a predisposing factor, with trastuzumab deruxtecan, it looked like patients of Asian ancestry were greater risk, but we need more data to really understand who’s at jeopardy.”

Dr. Burstein observed: “This is something patients need to be aware of as they’re contemplating this treatment.”

While data to prove the benefit of the drug need to mature, Dr. Burstein “would likely discontinue therapy” if a patient were to develop ILD or pneumonitis and treat accordingly.

As for T-DXd, he said: “It’s important that patients know that lung disease is a potentially severe side effect of treatment and that any respiratory symptoms need to be jumped on quickly.”

While prospective studies are now needed, and the phase 3 data should help to better understand the risk of ILD with T-DXd, Dr. Burstein believes it will be important to develop algorithms to ensure the safe administration of the drug.

These algorithms should include “appropriate surveillance and monitoring, especially as we think about trying to move this drug forward into the early stage setting where we’re using it in women who have favorable prognosis, and potentially curative situations for breast cancer.”

The trastuzumab deruxtecan trials were cosponsored by Daiichi Sankyo and AstraZeneca. The monarchE trial was supported by Eli Lilly.

Dr. Powell acknowledged receiving personal fees for acting as an advisory or consultant to both companies as well as to Voluntis. Dr. Burstein had nothing to disclose, and Dr. Cameron had no relevant financial interests in the data being presented.

Although rates are generally low, interstitial lung disease (ILD) can occur at any point in the first year of treatment with trastuzumab deruxtecan (T-DXd) for HER2-positive metastatic breast cancer (MBC).

That’s according to a pooled analysis of three early clinical trials with the drug that was reported at the European Society for Medical Oncology (ESMO): Breast Cancer virtual meeting.

Over a 5-year analysis period, the rate of any grade of ILD was 15.5%. The majority (79%) of those events were grade 1 or 2, observed pulmonologist Charles A. Powell, MD, of Icahn School of Medicine at Mount Sinai in New York, who presented the findings.

Of the 245 patients who were included in the analysis, 38 had an ILD event deemed related to treatment. A respective 9 (3.7%) and 21 (8.6%) had events graded as 1 or 2, 1 patient each (0.4%) had a grade 3 or 4 event, and 6 (2.4%) patients had a grade 5 event.

The timing of the first identified ILD event varied from 1.1 months to 20.8 months, given a median of 5.6 months overall. “This highlights an opportunity for more timely detection of ILD,” Dr. Powell suggested. He added that in almost all (97%) cases, ILD occurred before 12 months and the risk may even decrease over time “suggesting that the risk is not cumulative.”

He cautioned, however: “It is important to note that this analysis is exploratory and hypothesis generating in nature.”
 

ILD occurs with other cancer drugs

ILD is not just associated with T-DXd treatment, said the invited discussant for the trial, Harold J. Burstein, MD, PhD, of the Dana-Farber Cancer Institute in Boston.

“It’s important for clinicians to remember that ILD/pneumonitis is an uncommon, but potentially very serious side effect that affects many breast cancer treatments,” he said.

That not only includes T-DXd, but other newer drugs such the cyclin dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors, as well as other older more established drugs including taxanes, cyclophosphamide and even the mTOR inhibitor everolimus.

“Both clinicians and patients need to be aware of this risk. It’s part of the differential diagnosis for any patient who develops either ground glass changes or other infiltrates on a CT scan, or who has symptoms,” Dr. Burstein added.
 

Investigating ILD in T-DXd trials

T-DXd (Enhertu) is an anti-HER2-antibody drug conjugate that contains a humanized anti-HER2 IgG1 monoclonal antibody akin to trastuzumab that is linked to DXd, a topoisomerase I inhibitor that is a derivative of exatecan.

It has been approved for use in patients with HER2-positive metastatic breast cancer after two other HER2 treatments fail in the United States and Europe, and after chemotherapy in Japan, noted Dr. Powell. This is largely due to the results from the phase 2, open-label DESTINY-Breast01 trial.

“In breast cancer, T-DXd continues to demonstrate clinically meaningful efficacy with a median duration of response of more than 20 months in a heavily pretreated population,” he said. Objective response rates seen in the DESTINY-Breast01 trial were around 60%, and the median progression-free survival was a little over 19 months.

To look at the issue of drug-related ILD events in patients treated with T-DXd for HER2-positive MBC, an independent adjudication committee was formed to look at all the imaging and clinical data from the DESTINY-Breast01 trial and two single-arm phase 1 trials (NCT02564900 and NCT03383692).

In all, data on 245 patients who had been treated with T-DXd at the approved dose of 5.4 mg/kg in those trials between August 2015 and June 2020 were analyzed.
 

Dealing with lung toxicity

“We are getting new drugs to improve the treatment of cancer, but they always come with a price in terms of toxicity,” observed David Cameron, MD, professor of medical oncology at Edinburgh University in Scotland. Dr. Cameron chaired the session.

“Several measures were taken to identify and mitigate ILD,” across all the T-DXd studies, Dr. Powell explained. As well as the independent adjudication committee, available guidelines were followed and updated on how to diagnose and treat drug-induced lung injuries, and a “safe use” campaign was run in 2019.

Many patients in the early MBC studies were recruited before these measures were in place, such as the use of systemic steroids to manage low-grade events.

The bottom line, however, is that if a patient develops ILD then treatment should be stopped, Dr. Powell said. “Patients with grade 1 events may restart once the ILD has resolved, but those with grade 2 to 4 events must discontinue treatment.”

Dr. Powell concluded: “The overall clinical data support the positive risk-benefit profile of T-DXd. Phase 3 randomized controlled trials in breast cancer are ongoing.”
 

ILD also seen in monarchE trial with abemaciclib

Data on ILD events seen in the phase 3 monarchE trial were also reported separately at the ESMO Breast Cancer virtual meeting. The analysis population included 2,971 patients who had been treated with the CDK 4/6 inhibitor abemaciclib (Verzenio) together with endocrine therapy and 2,800 who had received endocrine therapy alone in the early-stage, adjuvant advanced breast cancer setting.

Most ILD (97%) events that occurred were single occurrences, with any grade of ILD occurring in a higher percentage of patients treated with abemaciclib with endocrine therapy than endocrine therapy alone (2.9% vs. 1.2%). Grade 3 events occurred in a respective 0.4% and 0.0% of patients.
 

So who’s at risk?

The risk factors for ILD and pneumonitis are not well characterized with either of the two drugs discussed, Dr. Burstein observed.

“In the abemaciclib experience, it looked like obesity might be a predisposing factor, with trastuzumab deruxtecan, it looked like patients of Asian ancestry were greater risk, but we need more data to really understand who’s at jeopardy.”

Dr. Burstein observed: “This is something patients need to be aware of as they’re contemplating this treatment.”

While data to prove the benefit of the drug need to mature, Dr. Burstein “would likely discontinue therapy” if a patient were to develop ILD or pneumonitis and treat accordingly.

As for T-DXd, he said: “It’s important that patients know that lung disease is a potentially severe side effect of treatment and that any respiratory symptoms need to be jumped on quickly.”

While prospective studies are now needed, and the phase 3 data should help to better understand the risk of ILD with T-DXd, Dr. Burstein believes it will be important to develop algorithms to ensure the safe administration of the drug.

These algorithms should include “appropriate surveillance and monitoring, especially as we think about trying to move this drug forward into the early stage setting where we’re using it in women who have favorable prognosis, and potentially curative situations for breast cancer.”

The trastuzumab deruxtecan trials were cosponsored by Daiichi Sankyo and AstraZeneca. The monarchE trial was supported by Eli Lilly.

Dr. Powell acknowledged receiving personal fees for acting as an advisory or consultant to both companies as well as to Voluntis. Dr. Burstein had nothing to disclose, and Dr. Cameron had no relevant financial interests in the data being presented.

Although rates are generally low, interstitial lung disease (ILD) can occur at any point in the first year of treatment with trastuzumab deruxtecan (T-DXd) for HER2-positive metastatic breast cancer (MBC).

That’s according to a pooled analysis of three early clinical trials with the drug that was reported at the European Society for Medical Oncology (ESMO): Breast Cancer virtual meeting.

Over a 5-year analysis period, the rate of any grade of ILD was 15.5%. The majority (79%) of those events were grade 1 or 2, observed pulmonologist Charles A. Powell, MD, of Icahn School of Medicine at Mount Sinai in New York, who presented the findings.

Of the 245 patients who were included in the analysis, 38 had an ILD event deemed related to treatment. A respective 9 (3.7%) and 21 (8.6%) had events graded as 1 or 2, 1 patient each (0.4%) had a grade 3 or 4 event, and 6 (2.4%) patients had a grade 5 event.

The timing of the first identified ILD event varied from 1.1 months to 20.8 months, given a median of 5.6 months overall. “This highlights an opportunity for more timely detection of ILD,” Dr. Powell suggested. He added that in almost all (97%) cases, ILD occurred before 12 months and the risk may even decrease over time “suggesting that the risk is not cumulative.”

He cautioned, however: “It is important to note that this analysis is exploratory and hypothesis generating in nature.”
 

ILD occurs with other cancer drugs

ILD is not just associated with T-DXd treatment, said the invited discussant for the trial, Harold J. Burstein, MD, PhD, of the Dana-Farber Cancer Institute in Boston.

“It’s important for clinicians to remember that ILD/pneumonitis is an uncommon, but potentially very serious side effect that affects many breast cancer treatments,” he said.

That not only includes T-DXd, but other newer drugs such the cyclin dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors, as well as other older more established drugs including taxanes, cyclophosphamide and even the mTOR inhibitor everolimus.

“Both clinicians and patients need to be aware of this risk. It’s part of the differential diagnosis for any patient who develops either ground glass changes or other infiltrates on a CT scan, or who has symptoms,” Dr. Burstein added.
 

Investigating ILD in T-DXd trials

T-DXd (Enhertu) is an anti-HER2-antibody drug conjugate that contains a humanized anti-HER2 IgG1 monoclonal antibody akin to trastuzumab that is linked to DXd, a topoisomerase I inhibitor that is a derivative of exatecan.

It has been approved for use in patients with HER2-positive metastatic breast cancer after two other HER2 treatments fail in the United States and Europe, and after chemotherapy in Japan, noted Dr. Powell. This is largely due to the results from the phase 2, open-label DESTINY-Breast01 trial.

“In breast cancer, T-DXd continues to demonstrate clinically meaningful efficacy with a median duration of response of more than 20 months in a heavily pretreated population,” he said. Objective response rates seen in the DESTINY-Breast01 trial were around 60%, and the median progression-free survival was a little over 19 months.

To look at the issue of drug-related ILD events in patients treated with T-DXd for HER2-positive MBC, an independent adjudication committee was formed to look at all the imaging and clinical data from the DESTINY-Breast01 trial and two single-arm phase 1 trials (NCT02564900 and NCT03383692).

In all, data on 245 patients who had been treated with T-DXd at the approved dose of 5.4 mg/kg in those trials between August 2015 and June 2020 were analyzed.
 

Dealing with lung toxicity

“We are getting new drugs to improve the treatment of cancer, but they always come with a price in terms of toxicity,” observed David Cameron, MD, professor of medical oncology at Edinburgh University in Scotland. Dr. Cameron chaired the session.

“Several measures were taken to identify and mitigate ILD,” across all the T-DXd studies, Dr. Powell explained. As well as the independent adjudication committee, available guidelines were followed and updated on how to diagnose and treat drug-induced lung injuries, and a “safe use” campaign was run in 2019.

Many patients in the early MBC studies were recruited before these measures were in place, such as the use of systemic steroids to manage low-grade events.

The bottom line, however, is that if a patient develops ILD then treatment should be stopped, Dr. Powell said. “Patients with grade 1 events may restart once the ILD has resolved, but those with grade 2 to 4 events must discontinue treatment.”

Dr. Powell concluded: “The overall clinical data support the positive risk-benefit profile of T-DXd. Phase 3 randomized controlled trials in breast cancer are ongoing.”
 

ILD also seen in monarchE trial with abemaciclib

Data on ILD events seen in the phase 3 monarchE trial were also reported separately at the ESMO Breast Cancer virtual meeting. The analysis population included 2,971 patients who had been treated with the CDK 4/6 inhibitor abemaciclib (Verzenio) together with endocrine therapy and 2,800 who had received endocrine therapy alone in the early-stage, adjuvant advanced breast cancer setting.

Most ILD (97%) events that occurred were single occurrences, with any grade of ILD occurring in a higher percentage of patients treated with abemaciclib with endocrine therapy than endocrine therapy alone (2.9% vs. 1.2%). Grade 3 events occurred in a respective 0.4% and 0.0% of patients.
 

So who’s at risk?

The risk factors for ILD and pneumonitis are not well characterized with either of the two drugs discussed, Dr. Burstein observed.

“In the abemaciclib experience, it looked like obesity might be a predisposing factor, with trastuzumab deruxtecan, it looked like patients of Asian ancestry were greater risk, but we need more data to really understand who’s at jeopardy.”

Dr. Burstein observed: “This is something patients need to be aware of as they’re contemplating this treatment.”

While data to prove the benefit of the drug need to mature, Dr. Burstein “would likely discontinue therapy” if a patient were to develop ILD or pneumonitis and treat accordingly.

As for T-DXd, he said: “It’s important that patients know that lung disease is a potentially severe side effect of treatment and that any respiratory symptoms need to be jumped on quickly.”

While prospective studies are now needed, and the phase 3 data should help to better understand the risk of ILD with T-DXd, Dr. Burstein believes it will be important to develop algorithms to ensure the safe administration of the drug.

These algorithms should include “appropriate surveillance and monitoring, especially as we think about trying to move this drug forward into the early stage setting where we’re using it in women who have favorable prognosis, and potentially curative situations for breast cancer.”

The trastuzumab deruxtecan trials were cosponsored by Daiichi Sankyo and AstraZeneca. The monarchE trial was supported by Eli Lilly.

Dr. Powell acknowledged receiving personal fees for acting as an advisory or consultant to both companies as well as to Voluntis. Dr. Burstein had nothing to disclose, and Dr. Cameron had no relevant financial interests in the data being presented.

The long-term benefits of endocrine therapy in premenopausal breast cancer appear to differ according to whether patients are categorized as high or low molecular risk using the 70-gene signature (MammaPrint).

Based upon data from patients who had participated in the Stockholm tamoxifen (STO-5) trial, high-risk patients significantly benefited from goserelin treatment, whereas low-risk patients benefited more from tamoxifen treatment when compared with no endocrine therapy.

“Goserelin, tamoxifen, and the combination of the two, reduced the 20-year risk of distant occurrences and fatal breast cancer, compared to no endocrine therapy,” Annelie Johansson, MSc, said at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Our findings indicate that the long-term endocrine therapy benefit in premenopausal patients is influenced by molecular risk classification and thus tumor characteristics,” she added.

Ms. Johansson, a postdoctoral researcher in genomic breast cancer at the Karolinska Institutet in Stockholm, reported the results of the analysis as a late-breaking abstract at the meeting.

“I think this is an innovative translational study trying to use the multigene assay results to look at differential endocrine therapy effects,” said Prudence Francis, MD, the invited discussant for study.

However, there are relatively few patients in the various subgroups being tested, she added. “We’ve also got short duration of tamoxifen, only 2 years, we’ve got prior chemotherapy in some patients and absence of HER2 therapy, all of which might influence outcomes.”

As a result, Dr. Francis, who is head of medical oncology at the Peter MacCallum Cancer Centre and a consultant Medical Oncologist at St. Vincent’s Hospital Melbourne, called the findings purely “hypothesis generating.”
 

Study details and results

The analysis was based on data from the STO-5 trial, which had recruited just over 900 patients between 1990 and 1997. Patients were stratified according to their lymph node status and some received chemotherapy with or without locoregional radiotherapy before being randomized to one of four study arms: goserelin alone, tamoxifen alone, the combination of the two, or no endocrine therapy.

Ms. Johansson noted that they were able to obtain the primary tumor blocks from 729 patients in the past year, of whom 610 were estrogen receptor positive. The analysis according to the 70-gene signature was then based on data from 465 patients: 131 had been treated with goserelin, 105 with tamoxifen, 120 with both, and 109 had received no endocrine treatment.

We have complete 20-year follow-up from high-quality Swedish National registries,” Ms. Johansson said, observing that the median age in the trial was 46 years.

Before stratifying patients into high and low risk using the 70-gene signature, the risk for having a distant recurrence, compared with no endocrine therapy was reduced by 52% with goserelin (hazard ratio, .48), 41% with tamoxifen (HR, 0.59), and 33% with both in combination (HR, 0.67).

After stratification, however, goserelin was associated with a 78% reduction of distant recurrence versus no endocrine treatment in high-risk patients (HR, 0.22) and a 20% reduction in low-risk patients (HR, 0.80).

Results in high- and low-risk patients with tamoxifen versus no endocrine treatment were a respective 31% reduction (HR, 0.69) and 62% reduction (HR, 0.38), and a respective 36% (HR, 0.64) and 28% (HR, 0.72) for the combination.

A further analysis was performed to compare between the active treatment arms, and this suggested a greater benefit of goserelin in patients at high risk when compared with both tamoxifen (HR, 0.30) and the combination (HR, 0.33).

Dr. Francis commented: “it is a bit surprising to find that goserelin appeared to be also better than the combination,” and it is something that the research team is looking into.

“One hypothesis might be if you look how the different treatments are working,” Ms. Johansson said. “Goserelin is very efficient in lowering the estrogen levels in premenopausal patients, suppressing the ovarian production of estrogen whereas tamoxifen can act both as an antagonist and agonist.

“So, we are thinking that maybe the addition of tamoxifen, with the agonistic properties of tamoxifen, might then make the goserelin not as efficient. But that’s of course, just a hypothesis right now and we need to look into this further,” she said.

The work was funded by The Swedish Research Council (Vetenskapsrådet), The Swedish Research Council for Health, Working life and Welfare, and the Swedish Cancer Society (Cancerfonden). Ms. Johansson had no personal disclosures; one of the coauthors was a coinventor of MammaPrint. Dr. Francis disclosed receiving travel support for overseas lectures from Ipsen and Novartis and acting as a medical oncology editor for Elsevier.

The long-term benefits of endocrine therapy in premenopausal breast cancer appear to differ according to whether patients are categorized as high or low molecular risk using the 70-gene signature (MammaPrint).

Based upon data from patients who had participated in the Stockholm tamoxifen (STO-5) trial, high-risk patients significantly benefited from goserelin treatment, whereas low-risk patients benefited more from tamoxifen treatment when compared with no endocrine therapy.

“Goserelin, tamoxifen, and the combination of the two, reduced the 20-year risk of distant occurrences and fatal breast cancer, compared to no endocrine therapy,” Annelie Johansson, MSc, said at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Our findings indicate that the long-term endocrine therapy benefit in premenopausal patients is influenced by molecular risk classification and thus tumor characteristics,” she added.

Ms. Johansson, a postdoctoral researcher in genomic breast cancer at the Karolinska Institutet in Stockholm, reported the results of the analysis as a late-breaking abstract at the meeting.

“I think this is an innovative translational study trying to use the multigene assay results to look at differential endocrine therapy effects,” said Prudence Francis, MD, the invited discussant for study.

However, there are relatively few patients in the various subgroups being tested, she added. “We’ve also got short duration of tamoxifen, only 2 years, we’ve got prior chemotherapy in some patients and absence of HER2 therapy, all of which might influence outcomes.”

As a result, Dr. Francis, who is head of medical oncology at the Peter MacCallum Cancer Centre and a consultant Medical Oncologist at St. Vincent’s Hospital Melbourne, called the findings purely “hypothesis generating.”
 

Study details and results

The analysis was based on data from the STO-5 trial, which had recruited just over 900 patients between 1990 and 1997. Patients were stratified according to their lymph node status and some received chemotherapy with or without locoregional radiotherapy before being randomized to one of four study arms: goserelin alone, tamoxifen alone, the combination of the two, or no endocrine therapy.

Ms. Johansson noted that they were able to obtain the primary tumor blocks from 729 patients in the past year, of whom 610 were estrogen receptor positive. The analysis according to the 70-gene signature was then based on data from 465 patients: 131 had been treated with goserelin, 105 with tamoxifen, 120 with both, and 109 had received no endocrine treatment.

We have complete 20-year follow-up from high-quality Swedish National registries,” Ms. Johansson said, observing that the median age in the trial was 46 years.

Before stratifying patients into high and low risk using the 70-gene signature, the risk for having a distant recurrence, compared with no endocrine therapy was reduced by 52% with goserelin (hazard ratio, .48), 41% with tamoxifen (HR, 0.59), and 33% with both in combination (HR, 0.67).

After stratification, however, goserelin was associated with a 78% reduction of distant recurrence versus no endocrine treatment in high-risk patients (HR, 0.22) and a 20% reduction in low-risk patients (HR, 0.80).

Results in high- and low-risk patients with tamoxifen versus no endocrine treatment were a respective 31% reduction (HR, 0.69) and 62% reduction (HR, 0.38), and a respective 36% (HR, 0.64) and 28% (HR, 0.72) for the combination.

A further analysis was performed to compare between the active treatment arms, and this suggested a greater benefit of goserelin in patients at high risk when compared with both tamoxifen (HR, 0.30) and the combination (HR, 0.33).

Dr. Francis commented: “it is a bit surprising to find that goserelin appeared to be also better than the combination,” and it is something that the research team is looking into.

“One hypothesis might be if you look how the different treatments are working,” Ms. Johansson said. “Goserelin is very efficient in lowering the estrogen levels in premenopausal patients, suppressing the ovarian production of estrogen whereas tamoxifen can act both as an antagonist and agonist.

“So, we are thinking that maybe the addition of tamoxifen, with the agonistic properties of tamoxifen, might then make the goserelin not as efficient. But that’s of course, just a hypothesis right now and we need to look into this further,” she said.

The work was funded by The Swedish Research Council (Vetenskapsrådet), The Swedish Research Council for Health, Working life and Welfare, and the Swedish Cancer Society (Cancerfonden). Ms. Johansson had no personal disclosures; one of the coauthors was a coinventor of MammaPrint. Dr. Francis disclosed receiving travel support for overseas lectures from Ipsen and Novartis and acting as a medical oncology editor for Elsevier.

The long-term benefits of endocrine therapy in premenopausal breast cancer appear to differ according to whether patients are categorized as high or low molecular risk using the 70-gene signature (MammaPrint).

Based upon data from patients who had participated in the Stockholm tamoxifen (STO-5) trial, high-risk patients significantly benefited from goserelin treatment, whereas low-risk patients benefited more from tamoxifen treatment when compared with no endocrine therapy.

“Goserelin, tamoxifen, and the combination of the two, reduced the 20-year risk of distant occurrences and fatal breast cancer, compared to no endocrine therapy,” Annelie Johansson, MSc, said at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Our findings indicate that the long-term endocrine therapy benefit in premenopausal patients is influenced by molecular risk classification and thus tumor characteristics,” she added.

Ms. Johansson, a postdoctoral researcher in genomic breast cancer at the Karolinska Institutet in Stockholm, reported the results of the analysis as a late-breaking abstract at the meeting.

“I think this is an innovative translational study trying to use the multigene assay results to look at differential endocrine therapy effects,” said Prudence Francis, MD, the invited discussant for study.

However, there are relatively few patients in the various subgroups being tested, she added. “We’ve also got short duration of tamoxifen, only 2 years, we’ve got prior chemotherapy in some patients and absence of HER2 therapy, all of which might influence outcomes.”

As a result, Dr. Francis, who is head of medical oncology at the Peter MacCallum Cancer Centre and a consultant Medical Oncologist at St. Vincent’s Hospital Melbourne, called the findings purely “hypothesis generating.”
 

Study details and results

The analysis was based on data from the STO-5 trial, which had recruited just over 900 patients between 1990 and 1997. Patients were stratified according to their lymph node status and some received chemotherapy with or without locoregional radiotherapy before being randomized to one of four study arms: goserelin alone, tamoxifen alone, the combination of the two, or no endocrine therapy.

Ms. Johansson noted that they were able to obtain the primary tumor blocks from 729 patients in the past year, of whom 610 were estrogen receptor positive. The analysis according to the 70-gene signature was then based on data from 465 patients: 131 had been treated with goserelin, 105 with tamoxifen, 120 with both, and 109 had received no endocrine treatment.

We have complete 20-year follow-up from high-quality Swedish National registries,” Ms. Johansson said, observing that the median age in the trial was 46 years.

Before stratifying patients into high and low risk using the 70-gene signature, the risk for having a distant recurrence, compared with no endocrine therapy was reduced by 52% with goserelin (hazard ratio, .48), 41% with tamoxifen (HR, 0.59), and 33% with both in combination (HR, 0.67).

After stratification, however, goserelin was associated with a 78% reduction of distant recurrence versus no endocrine treatment in high-risk patients (HR, 0.22) and a 20% reduction in low-risk patients (HR, 0.80).

Results in high- and low-risk patients with tamoxifen versus no endocrine treatment were a respective 31% reduction (HR, 0.69) and 62% reduction (HR, 0.38), and a respective 36% (HR, 0.64) and 28% (HR, 0.72) for the combination.

A further analysis was performed to compare between the active treatment arms, and this suggested a greater benefit of goserelin in patients at high risk when compared with both tamoxifen (HR, 0.30) and the combination (HR, 0.33).

Dr. Francis commented: “it is a bit surprising to find that goserelin appeared to be also better than the combination,” and it is something that the research team is looking into.

“One hypothesis might be if you look how the different treatments are working,” Ms. Johansson said. “Goserelin is very efficient in lowering the estrogen levels in premenopausal patients, suppressing the ovarian production of estrogen whereas tamoxifen can act both as an antagonist and agonist.

“So, we are thinking that maybe the addition of tamoxifen, with the agonistic properties of tamoxifen, might then make the goserelin not as efficient. But that’s of course, just a hypothesis right now and we need to look into this further,” she said.

The work was funded by The Swedish Research Council (Vetenskapsrådet), The Swedish Research Council for Health, Working life and Welfare, and the Swedish Cancer Society (Cancerfonden). Ms. Johansson had no personal disclosures; one of the coauthors was a coinventor of MammaPrint. Dr. Francis disclosed receiving travel support for overseas lectures from Ipsen and Novartis and acting as a medical oncology editor for Elsevier.

The PD-L1 inhibitor atezolizumab (Tecentriq) combined with carboplatin has shown signs of clinical activity in women with metastatic invasive lobular breast cancer (ILC) according to the first results to come from the ongoing GELATO trial.

The 6-month objective response rate was 19%, based on 4 of 21 patients who could be evaluated exhibiting a partial response to the chemoimmunotherapy. A further two (10%) patients had stable disease, meaning that clinical benefit rate was 29%.

GELATO (AssessinG Efficacy of Carboplatin and ATezOlizumab in Metastatic Lobular Breast Cancer) is a phase 2 trial being conducted at four Dutch centers. The primary premise of the study is that “there’s an immune-related subtype of ILC,” researcher Leonie Voorwerk, BSc, reported at the European Society for Medical Oncology: Breast Cancer virtual meeting (Abstract LBA3).

This ILC subtype is “characterized by high expression of immune-related genes and high levels of TILs [tumor-infiltrating lymphocytes] and PDL-1,” said Ms. Voorwerk, a PhD student working with medical oncologist Marleen Kok, MD, PhD, at the Netherlands Cancer Institute in Amsterdam.

Furthermore, she added, in vitro data suggest sensitivity of immune-related-ILCs to platinum and there is preclinical work showing that there is synergy between platinum-based chemotherapy and checkpoint blockade.
 

First chemoimmunotherapy trial in lobular cancer setting

GELATO is a significant trial as it is “the first chemoimmunotherapy trial in metastatic lobular breast cancer,” said Sylvia Adams, MD, professor of medicine and director of the Breast Cancer Center at NYU Langone Health in New York City.

“Of note, the further research should include the immune-related genes and TMB [tumor mutational burden],” proposed Dr. Adams, who was not involved in the trial.

“We should look to tumor mutational burden because while it is not typically high in early disease, metastatic lesions can have higher TMB,” she explained. “Also, metastatic ILC is known to have higher tumor mutational burden compared to IDC [invasive ductal carcinoma], so this is an important thing along with the clinical factors as described in looking at outcomes.”
 

Trial design and patient characteristics

GELATO is a single-arm, nonrandomized trial in which 37 patients with metastatic ILC were screened for inclusion between November 2017 and January 2021. A total of 26 of these patients were registered for the trial, and 23 have so far received at least one cycle of atezolizumab.

Prerequisites for entry into the trial were that patients had to have negative or aberrant E-cadherin, a characteristic feature of ILC. Patients with estrogen receptor (ER)-positive (ER+) disease could be included, but they had to be proven to be resistant to endocrine therapies. No more than two prior lines of palliative chemotherapy were allowed, and all participants had to have lactose dehydrogenase levels of less than 2 times the upper limit of normal.

Patients were then treated with up to 12 cycles of weekly carboplatin (AUC = 1.5 mg/mL/min), with atezolizumab (1,200 mg) added in from cycle 3 onward. Treatment was continued until disease progression or unacceptable toxicity occurred.

“Baseline characteristics were mainly as expected for this patient population,” Ms. Voorwerk stated. Patients were aged 45-89 years, with a median of 60 years. Around half each had a WHO performance status of 0 or 1, and around half each had one to two or three or more metastatic sites; 78% had liver metastases.

“But I want to highlight that we included five patients with the triple-negative ILC,” said Ms. Voorwerk, also highlighting that approximately 50% of patients had received prior palliative chemotherapy. Later in her presentation she noted that four out of the six patients that showed any clinical benefit had triple negative disease.
 

Key findings and next steps

The primary endpoint was progression-free survival (PFS) at 6 months, with secondary endpoints of the best overall response rate, PFS at 1 year, overall survival, and safety.

While details of the latter three endpoints are yet to be reported, Ms. Voorwerk noted that there was a median duration of response of 12 weeks and the median PFS was 15 weeks. The primary endpoint of PFS was met as four patients were free of progression at 6 months and the statistical method used called for patients to be progression free at this time point.

“We observed that stromal TILs and CD8+ cells were not associated with clinical benefits,” said Ms. Voorwerk. There was, however, “a slight trend” toward higher PD-L1 expression in responding patients.

“Further translational research is needed to provide the rationale for new strategies to improve checkpoint blockade in patients with lobular breast cancer,” she concluded.

Dr. Adams concurred, adding that a future research question was whether either atezolizumab or carboplatin was contributing to the response. This is “difficult to tell as the study was a single arm trial.”

Another question, said Dr. Adams, is are “anti-CDK 4/6 inhibitors helpful in improving response rates and durability?” In the trial, 70% of patients had prior exposure to CDK 4/6 inhibitors.

The GELATO trial was sponsored by the Netherlands Cancer Institute with funding from Roche Pharma AG. Ms. Voorwerk had nothing to disclose. Dr. Adams disclosed uncompensated consulting or advisory roles with Bristol-Myers Squibb, Genentech, and Merck from whom she has received research funding. Dr. Adams also disclosed research funding from Amgen, Celgene, and Novartis.

The PD-L1 inhibitor atezolizumab (Tecentriq) combined with carboplatin has shown signs of clinical activity in women with metastatic invasive lobular breast cancer (ILC) according to the first results to come from the ongoing GELATO trial.

The 6-month objective response rate was 19%, based on 4 of 21 patients who could be evaluated exhibiting a partial response to the chemoimmunotherapy. A further two (10%) patients had stable disease, meaning that clinical benefit rate was 29%.

GELATO (AssessinG Efficacy of Carboplatin and ATezOlizumab in Metastatic Lobular Breast Cancer) is a phase 2 trial being conducted at four Dutch centers. The primary premise of the study is that “there’s an immune-related subtype of ILC,” researcher Leonie Voorwerk, BSc, reported at the European Society for Medical Oncology: Breast Cancer virtual meeting (Abstract LBA3).

This ILC subtype is “characterized by high expression of immune-related genes and high levels of TILs [tumor-infiltrating lymphocytes] and PDL-1,” said Ms. Voorwerk, a PhD student working with medical oncologist Marleen Kok, MD, PhD, at the Netherlands Cancer Institute in Amsterdam.

Furthermore, she added, in vitro data suggest sensitivity of immune-related-ILCs to platinum and there is preclinical work showing that there is synergy between platinum-based chemotherapy and checkpoint blockade.
 

First chemoimmunotherapy trial in lobular cancer setting

GELATO is a significant trial as it is “the first chemoimmunotherapy trial in metastatic lobular breast cancer,” said Sylvia Adams, MD, professor of medicine and director of the Breast Cancer Center at NYU Langone Health in New York City.

“Of note, the further research should include the immune-related genes and TMB [tumor mutational burden],” proposed Dr. Adams, who was not involved in the trial.

“We should look to tumor mutational burden because while it is not typically high in early disease, metastatic lesions can have higher TMB,” she explained. “Also, metastatic ILC is known to have higher tumor mutational burden compared to IDC [invasive ductal carcinoma], so this is an important thing along with the clinical factors as described in looking at outcomes.”
 

Trial design and patient characteristics

GELATO is a single-arm, nonrandomized trial in which 37 patients with metastatic ILC were screened for inclusion between November 2017 and January 2021. A total of 26 of these patients were registered for the trial, and 23 have so far received at least one cycle of atezolizumab.

Prerequisites for entry into the trial were that patients had to have negative or aberrant E-cadherin, a characteristic feature of ILC. Patients with estrogen receptor (ER)-positive (ER+) disease could be included, but they had to be proven to be resistant to endocrine therapies. No more than two prior lines of palliative chemotherapy were allowed, and all participants had to have lactose dehydrogenase levels of less than 2 times the upper limit of normal.

Patients were then treated with up to 12 cycles of weekly carboplatin (AUC = 1.5 mg/mL/min), with atezolizumab (1,200 mg) added in from cycle 3 onward. Treatment was continued until disease progression or unacceptable toxicity occurred.

“Baseline characteristics were mainly as expected for this patient population,” Ms. Voorwerk stated. Patients were aged 45-89 years, with a median of 60 years. Around half each had a WHO performance status of 0 or 1, and around half each had one to two or three or more metastatic sites; 78% had liver metastases.

“But I want to highlight that we included five patients with the triple-negative ILC,” said Ms. Voorwerk, also highlighting that approximately 50% of patients had received prior palliative chemotherapy. Later in her presentation she noted that four out of the six patients that showed any clinical benefit had triple negative disease.
 

Key findings and next steps

The primary endpoint was progression-free survival (PFS) at 6 months, with secondary endpoints of the best overall response rate, PFS at 1 year, overall survival, and safety.

While details of the latter three endpoints are yet to be reported, Ms. Voorwerk noted that there was a median duration of response of 12 weeks and the median PFS was 15 weeks. The primary endpoint of PFS was met as four patients were free of progression at 6 months and the statistical method used called for patients to be progression free at this time point.

“We observed that stromal TILs and CD8+ cells were not associated with clinical benefits,” said Ms. Voorwerk. There was, however, “a slight trend” toward higher PD-L1 expression in responding patients.

“Further translational research is needed to provide the rationale for new strategies to improve checkpoint blockade in patients with lobular breast cancer,” she concluded.

Dr. Adams concurred, adding that a future research question was whether either atezolizumab or carboplatin was contributing to the response. This is “difficult to tell as the study was a single arm trial.”

Another question, said Dr. Adams, is are “anti-CDK 4/6 inhibitors helpful in improving response rates and durability?” In the trial, 70% of patients had prior exposure to CDK 4/6 inhibitors.

The GELATO trial was sponsored by the Netherlands Cancer Institute with funding from Roche Pharma AG. Ms. Voorwerk had nothing to disclose. Dr. Adams disclosed uncompensated consulting or advisory roles with Bristol-Myers Squibb, Genentech, and Merck from whom she has received research funding. Dr. Adams also disclosed research funding from Amgen, Celgene, and Novartis.

The PD-L1 inhibitor atezolizumab (Tecentriq) combined with carboplatin has shown signs of clinical activity in women with metastatic invasive lobular breast cancer (ILC) according to the first results to come from the ongoing GELATO trial.

The 6-month objective response rate was 19%, based on 4 of 21 patients who could be evaluated exhibiting a partial response to the chemoimmunotherapy. A further two (10%) patients had stable disease, meaning that clinical benefit rate was 29%.

GELATO (AssessinG Efficacy of Carboplatin and ATezOlizumab in Metastatic Lobular Breast Cancer) is a phase 2 trial being conducted at four Dutch centers. The primary premise of the study is that “there’s an immune-related subtype of ILC,” researcher Leonie Voorwerk, BSc, reported at the European Society for Medical Oncology: Breast Cancer virtual meeting (Abstract LBA3).

This ILC subtype is “characterized by high expression of immune-related genes and high levels of TILs [tumor-infiltrating lymphocytes] and PDL-1,” said Ms. Voorwerk, a PhD student working with medical oncologist Marleen Kok, MD, PhD, at the Netherlands Cancer Institute in Amsterdam.

Furthermore, she added, in vitro data suggest sensitivity of immune-related-ILCs to platinum and there is preclinical work showing that there is synergy between platinum-based chemotherapy and checkpoint blockade.
 

First chemoimmunotherapy trial in lobular cancer setting

GELATO is a significant trial as it is “the first chemoimmunotherapy trial in metastatic lobular breast cancer,” said Sylvia Adams, MD, professor of medicine and director of the Breast Cancer Center at NYU Langone Health in New York City.

“Of note, the further research should include the immune-related genes and TMB [tumor mutational burden],” proposed Dr. Adams, who was not involved in the trial.

“We should look to tumor mutational burden because while it is not typically high in early disease, metastatic lesions can have higher TMB,” she explained. “Also, metastatic ILC is known to have higher tumor mutational burden compared to IDC [invasive ductal carcinoma], so this is an important thing along with the clinical factors as described in looking at outcomes.”
 

Trial design and patient characteristics

GELATO is a single-arm, nonrandomized trial in which 37 patients with metastatic ILC were screened for inclusion between November 2017 and January 2021. A total of 26 of these patients were registered for the trial, and 23 have so far received at least one cycle of atezolizumab.

Prerequisites for entry into the trial were that patients had to have negative or aberrant E-cadherin, a characteristic feature of ILC. Patients with estrogen receptor (ER)-positive (ER+) disease could be included, but they had to be proven to be resistant to endocrine therapies. No more than two prior lines of palliative chemotherapy were allowed, and all participants had to have lactose dehydrogenase levels of less than 2 times the upper limit of normal.

Patients were then treated with up to 12 cycles of weekly carboplatin (AUC = 1.5 mg/mL/min), with atezolizumab (1,200 mg) added in from cycle 3 onward. Treatment was continued until disease progression or unacceptable toxicity occurred.

“Baseline characteristics were mainly as expected for this patient population,” Ms. Voorwerk stated. Patients were aged 45-89 years, with a median of 60 years. Around half each had a WHO performance status of 0 or 1, and around half each had one to two or three or more metastatic sites; 78% had liver metastases.

“But I want to highlight that we included five patients with the triple-negative ILC,” said Ms. Voorwerk, also highlighting that approximately 50% of patients had received prior palliative chemotherapy. Later in her presentation she noted that four out of the six patients that showed any clinical benefit had triple negative disease.
 

Key findings and next steps

The primary endpoint was progression-free survival (PFS) at 6 months, with secondary endpoints of the best overall response rate, PFS at 1 year, overall survival, and safety.

While details of the latter three endpoints are yet to be reported, Ms. Voorwerk noted that there was a median duration of response of 12 weeks and the median PFS was 15 weeks. The primary endpoint of PFS was met as four patients were free of progression at 6 months and the statistical method used called for patients to be progression free at this time point.

“We observed that stromal TILs and CD8+ cells were not associated with clinical benefits,” said Ms. Voorwerk. There was, however, “a slight trend” toward higher PD-L1 expression in responding patients.

“Further translational research is needed to provide the rationale for new strategies to improve checkpoint blockade in patients with lobular breast cancer,” she concluded.

Dr. Adams concurred, adding that a future research question was whether either atezolizumab or carboplatin was contributing to the response. This is “difficult to tell as the study was a single arm trial.”

Another question, said Dr. Adams, is are “anti-CDK 4/6 inhibitors helpful in improving response rates and durability?” In the trial, 70% of patients had prior exposure to CDK 4/6 inhibitors.

The GELATO trial was sponsored by the Netherlands Cancer Institute with funding from Roche Pharma AG. Ms. Voorwerk had nothing to disclose. Dr. Adams disclosed uncompensated consulting or advisory roles with Bristol-Myers Squibb, Genentech, and Merck from whom she has received research funding. Dr. Adams also disclosed research funding from Amgen, Celgene, and Novartis.

Three-year survival rates were similarly high among postmenopausal women with high-risk early luminal breast cancer who were treated with either the neoadjuvant combination of letrozole and palbociclib (Ibrance) or standard neoadjuvant chemotherapy in the phase 2 NeoPAL study.

Progression-free survival (PFS) was a respective 86.7% and 87.2%, with a hazard ratio (HR) of 1.01 (P = .98) comparing the endocrine therapy and cyclin-dependent kinase (CDK) 4/6 inhibitor combination versus FEC/taxane chemotherapy.

There were also no differences between the two treatment arms in terms of invasive disease-free survival (iDFS, HR = 0.83, P = .71) or breast cancer–specific survival (BCSS), although the latter was an exploratory endpoint alongside overall survival (OS).

“The lack of difference is impressive,” said Hope S. Rugo, MD, FASCO, who commented independently on the study’s findings after their presentation at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Overall survival in patients who received chemotherapy appears to be better, but the very small numbers here make interpretation of this difference impossible,” observed Dr. Rugo, professor of medicine at the University of California San Francisco’s Helen Diller Family Comprehensive Cancer Center.

“Unfortunately, this study is underpowered for definitive conclusions,” acknowledged study investigator Suzette Delaloge, MD, associate professor of medical oncology at Institut Gustave Roussy in Villejuif, France.

However, “it shows that the nonchemotherapy, preoperative letrozole/palbociclib approach deserves further exploration and could be an option for a chemotherapy-free regimen in some specific cases.”
 

Primary data already reported

The NeoPAL study was an open-label, randomized study conducted in 27 centers throughout France that compared the preoperative use of letrozole plus palbociclib to neoadjuvant chemotherapy in 106 postmenopausal patients with either luminal A or B node-positive disease.

Patients were considered for inclusion in the trial if they had been newly diagnosed with estrogen receptor (ER)-positive, HER2-negative stage I-III breast cancer and were not candidates for breast conservation. Genetic testing was used to confirm that only those with luminal B, or luminal A and who were node positive were recruited.

Neoadjuvant treatment consisted of either letrozole (2.5 mg/day) and palbociclib (125 mg daily for 3 weeks out of 4 weeks) for 19 weeks or three 21-day cycles of 5-fluorouracil (500 mg/m²), epirubicin (100 mg/m²), and cyclophosphamide (500 mg/m²), followed by three 21-day cycles of docetaxel (100 mg/m²).

The primary endpoint was the pathological complete response (pCR), defined as a residual cancer burden (RCB) of 0 to 1. Results, which have already been reported, showed equivalent, but perhaps disappointingly low, pathological responses in both the letrozole/palbociclib and chemotherapy arms (3.8% and 5.9%, respectively).

There were, however, identical clinical responses (at around 75%) and “encouraging biomarker responses in the Prosigna-defined high risk luminal breast cancer population,” Dr. Delaloge said.

The NeoPAL findings were on par with those of the CORALLEEN study, Dr. Delaloge suggested. That trial, as Dr. Rugo has also pointed out, was conducted in 106 patients with luminal B early breast cancer and used a combination of letrozole and the CDK 4/6 inhibitor ribociclib (Kisquali).
 

Future studies needed

NeoPAL “is a small study with relatively short follow-up even for hormone receptor-positive, high-risk disease,” Dr. Rugo observed. However, she qualified “this short follow-up can be very meaningful in high-risk disease.” as shown by other CDK 4/6 inhibitor trials.

Dr. Rugo also noted: “Short-term biologic endpoints are clearly more informative following and during neoadjuvant endocrine therapy than pCR and this trial, as well as the data from previous studies, indicates that this is the case.”

Further, Dr. Rugo said: “Antiproliferative response is enhanced with CDK 4/6 inhibitors, but this doesn’t seem to translate into a difference in pCR. The lack of impact on longer term, outcome to date, provides support for ongoing trials.”

Two such trials are already underway. The 200-patient CARABELA trial started recruitment in March last year and is comparing endocrine therapy with letrozole plus the CDK 4/6 inhibitor abemaciclib (Verzenio) to standard chemotherapy in patients with hormone receptor–positive, high-risk Ki67 disease.

Then there is the ADAPTcycle trial, a large open-label, phase 3 trial that is randomizing patients based on Ki67 and recurrence score after a short preoperative induction with endocrine therapy to postoperative chemotherapy or to 2 years of endocrine therapy plus ribociclib, with both arms receiving a standard course of 5 years of endocrine therapy.

“These two studies have provided interesting information that will help us design studies in the future,” said Dr. Rugo.

Not only that, but they will also help “investigate the subgroups of patients that benefit the most from CDK 4/6 inhibitors and better study neoadjuvant endocrine therapy which is an important option for patients that can be evaluated in terms of its efficacy by short term measures of antiproliferative response.”

NeoPAL was sponsored by UNICANCER with funding from Pfizer and NanoString Technologies. Dr. Delaloge disclosed receiving research grants or funding via her institution from Pfizer, AstraZeneca, Roche, Merck, Sanofi, Lilly, Novartis, BMS, Orion, Daiichi, Puma, and Pierre Fabre. Dr. Rugo reported receipt of grants via her institution to perform clinical trials from Pfizer and multiple other companies. She disclosed receiving honoraria from PUMA, Samsung, and Mylan.

Three-year survival rates were similarly high among postmenopausal women with high-risk early luminal breast cancer who were treated with either the neoadjuvant combination of letrozole and palbociclib (Ibrance) or standard neoadjuvant chemotherapy in the phase 2 NeoPAL study.

Progression-free survival (PFS) was a respective 86.7% and 87.2%, with a hazard ratio (HR) of 1.01 (P = .98) comparing the endocrine therapy and cyclin-dependent kinase (CDK) 4/6 inhibitor combination versus FEC/taxane chemotherapy.

There were also no differences between the two treatment arms in terms of invasive disease-free survival (iDFS, HR = 0.83, P = .71) or breast cancer–specific survival (BCSS), although the latter was an exploratory endpoint alongside overall survival (OS).

“The lack of difference is impressive,” said Hope S. Rugo, MD, FASCO, who commented independently on the study’s findings after their presentation at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Overall survival in patients who received chemotherapy appears to be better, but the very small numbers here make interpretation of this difference impossible,” observed Dr. Rugo, professor of medicine at the University of California San Francisco’s Helen Diller Family Comprehensive Cancer Center.

“Unfortunately, this study is underpowered for definitive conclusions,” acknowledged study investigator Suzette Delaloge, MD, associate professor of medical oncology at Institut Gustave Roussy in Villejuif, France.

However, “it shows that the nonchemotherapy, preoperative letrozole/palbociclib approach deserves further exploration and could be an option for a chemotherapy-free regimen in some specific cases.”
 

Primary data already reported

The NeoPAL study was an open-label, randomized study conducted in 27 centers throughout France that compared the preoperative use of letrozole plus palbociclib to neoadjuvant chemotherapy in 106 postmenopausal patients with either luminal A or B node-positive disease.

Patients were considered for inclusion in the trial if they had been newly diagnosed with estrogen receptor (ER)-positive, HER2-negative stage I-III breast cancer and were not candidates for breast conservation. Genetic testing was used to confirm that only those with luminal B, or luminal A and who were node positive were recruited.

Neoadjuvant treatment consisted of either letrozole (2.5 mg/day) and palbociclib (125 mg daily for 3 weeks out of 4 weeks) for 19 weeks or three 21-day cycles of 5-fluorouracil (500 mg/m²), epirubicin (100 mg/m²), and cyclophosphamide (500 mg/m²), followed by three 21-day cycles of docetaxel (100 mg/m²).

The primary endpoint was the pathological complete response (pCR), defined as a residual cancer burden (RCB) of 0 to 1. Results, which have already been reported, showed equivalent, but perhaps disappointingly low, pathological responses in both the letrozole/palbociclib and chemotherapy arms (3.8% and 5.9%, respectively).

There were, however, identical clinical responses (at around 75%) and “encouraging biomarker responses in the Prosigna-defined high risk luminal breast cancer population,” Dr. Delaloge said.

The NeoPAL findings were on par with those of the CORALLEEN study, Dr. Delaloge suggested. That trial, as Dr. Rugo has also pointed out, was conducted in 106 patients with luminal B early breast cancer and used a combination of letrozole and the CDK 4/6 inhibitor ribociclib (Kisquali).
 

Future studies needed

NeoPAL “is a small study with relatively short follow-up even for hormone receptor-positive, high-risk disease,” Dr. Rugo observed. However, she qualified “this short follow-up can be very meaningful in high-risk disease.” as shown by other CDK 4/6 inhibitor trials.

Dr. Rugo also noted: “Short-term biologic endpoints are clearly more informative following and during neoadjuvant endocrine therapy than pCR and this trial, as well as the data from previous studies, indicates that this is the case.”

Further, Dr. Rugo said: “Antiproliferative response is enhanced with CDK 4/6 inhibitors, but this doesn’t seem to translate into a difference in pCR. The lack of impact on longer term, outcome to date, provides support for ongoing trials.”

Two such trials are already underway. The 200-patient CARABELA trial started recruitment in March last year and is comparing endocrine therapy with letrozole plus the CDK 4/6 inhibitor abemaciclib (Verzenio) to standard chemotherapy in patients with hormone receptor–positive, high-risk Ki67 disease.

Then there is the ADAPTcycle trial, a large open-label, phase 3 trial that is randomizing patients based on Ki67 and recurrence score after a short preoperative induction with endocrine therapy to postoperative chemotherapy or to 2 years of endocrine therapy plus ribociclib, with both arms receiving a standard course of 5 years of endocrine therapy.

“These two studies have provided interesting information that will help us design studies in the future,” said Dr. Rugo.

Not only that, but they will also help “investigate the subgroups of patients that benefit the most from CDK 4/6 inhibitors and better study neoadjuvant endocrine therapy which is an important option for patients that can be evaluated in terms of its efficacy by short term measures of antiproliferative response.”

NeoPAL was sponsored by UNICANCER with funding from Pfizer and NanoString Technologies. Dr. Delaloge disclosed receiving research grants or funding via her institution from Pfizer, AstraZeneca, Roche, Merck, Sanofi, Lilly, Novartis, BMS, Orion, Daiichi, Puma, and Pierre Fabre. Dr. Rugo reported receipt of grants via her institution to perform clinical trials from Pfizer and multiple other companies. She disclosed receiving honoraria from PUMA, Samsung, and Mylan.

Three-year survival rates were similarly high among postmenopausal women with high-risk early luminal breast cancer who were treated with either the neoadjuvant combination of letrozole and palbociclib (Ibrance) or standard neoadjuvant chemotherapy in the phase 2 NeoPAL study.

Progression-free survival (PFS) was a respective 86.7% and 87.2%, with a hazard ratio (HR) of 1.01 (P = .98) comparing the endocrine therapy and cyclin-dependent kinase (CDK) 4/6 inhibitor combination versus FEC/taxane chemotherapy.

There were also no differences between the two treatment arms in terms of invasive disease-free survival (iDFS, HR = 0.83, P = .71) or breast cancer–specific survival (BCSS), although the latter was an exploratory endpoint alongside overall survival (OS).

“The lack of difference is impressive,” said Hope S. Rugo, MD, FASCO, who commented independently on the study’s findings after their presentation at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Overall survival in patients who received chemotherapy appears to be better, but the very small numbers here make interpretation of this difference impossible,” observed Dr. Rugo, professor of medicine at the University of California San Francisco’s Helen Diller Family Comprehensive Cancer Center.

“Unfortunately, this study is underpowered for definitive conclusions,” acknowledged study investigator Suzette Delaloge, MD, associate professor of medical oncology at Institut Gustave Roussy in Villejuif, France.

However, “it shows that the nonchemotherapy, preoperative letrozole/palbociclib approach deserves further exploration and could be an option for a chemotherapy-free regimen in some specific cases.”
 

Primary data already reported

The NeoPAL study was an open-label, randomized study conducted in 27 centers throughout France that compared the preoperative use of letrozole plus palbociclib to neoadjuvant chemotherapy in 106 postmenopausal patients with either luminal A or B node-positive disease.

Patients were considered for inclusion in the trial if they had been newly diagnosed with estrogen receptor (ER)-positive, HER2-negative stage I-III breast cancer and were not candidates for breast conservation. Genetic testing was used to confirm that only those with luminal B, or luminal A and who were node positive were recruited.

Neoadjuvant treatment consisted of either letrozole (2.5 mg/day) and palbociclib (125 mg daily for 3 weeks out of 4 weeks) for 19 weeks or three 21-day cycles of 5-fluorouracil (500 mg/m²), epirubicin (100 mg/m²), and cyclophosphamide (500 mg/m²), followed by three 21-day cycles of docetaxel (100 mg/m²).

The primary endpoint was the pathological complete response (pCR), defined as a residual cancer burden (RCB) of 0 to 1. Results, which have already been reported, showed equivalent, but perhaps disappointingly low, pathological responses in both the letrozole/palbociclib and chemotherapy arms (3.8% and 5.9%, respectively).

There were, however, identical clinical responses (at around 75%) and “encouraging biomarker responses in the Prosigna-defined high risk luminal breast cancer population,” Dr. Delaloge said.

The NeoPAL findings were on par with those of the CORALLEEN study, Dr. Delaloge suggested. That trial, as Dr. Rugo has also pointed out, was conducted in 106 patients with luminal B early breast cancer and used a combination of letrozole and the CDK 4/6 inhibitor ribociclib (Kisquali).
 

Future studies needed

NeoPAL “is a small study with relatively short follow-up even for hormone receptor-positive, high-risk disease,” Dr. Rugo observed. However, she qualified “this short follow-up can be very meaningful in high-risk disease.” as shown by other CDK 4/6 inhibitor trials.

Dr. Rugo also noted: “Short-term biologic endpoints are clearly more informative following and during neoadjuvant endocrine therapy than pCR and this trial, as well as the data from previous studies, indicates that this is the case.”

Further, Dr. Rugo said: “Antiproliferative response is enhanced with CDK 4/6 inhibitors, but this doesn’t seem to translate into a difference in pCR. The lack of impact on longer term, outcome to date, provides support for ongoing trials.”

Two such trials are already underway. The 200-patient CARABELA trial started recruitment in March last year and is comparing endocrine therapy with letrozole plus the CDK 4/6 inhibitor abemaciclib (Verzenio) to standard chemotherapy in patients with hormone receptor–positive, high-risk Ki67 disease.

Then there is the ADAPTcycle trial, a large open-label, phase 3 trial that is randomizing patients based on Ki67 and recurrence score after a short preoperative induction with endocrine therapy to postoperative chemotherapy or to 2 years of endocrine therapy plus ribociclib, with both arms receiving a standard course of 5 years of endocrine therapy.

“These two studies have provided interesting information that will help us design studies in the future,” said Dr. Rugo.

Not only that, but they will also help “investigate the subgroups of patients that benefit the most from CDK 4/6 inhibitors and better study neoadjuvant endocrine therapy which is an important option for patients that can be evaluated in terms of its efficacy by short term measures of antiproliferative response.”

NeoPAL was sponsored by UNICANCER with funding from Pfizer and NanoString Technologies. Dr. Delaloge disclosed receiving research grants or funding via her institution from Pfizer, AstraZeneca, Roche, Merck, Sanofi, Lilly, Novartis, BMS, Orion, Daiichi, Puma, and Pierre Fabre. Dr. Rugo reported receipt of grants via her institution to perform clinical trials from Pfizer and multiple other companies. She disclosed receiving honoraria from PUMA, Samsung, and Mylan.

Dual HER2 blockade with pertuzumab (Perjeta) and trastuzumab (Herceptin) on top of anthracycline-based neoadjuvant chemotherapy for early-stage breast cancer was associated with a low rate of clinically relevant cardiac events in the final follow-up of the BERENICE study.

After more than 5 years, 1.0%-1.5% of patients who had locally advanced, inflammatory, or early-stage breast cancer developed heart failure, and around 12%-13% showed any significant changes in left ventricular ejection fraction (LVEF).

Importantly, “there were no new safety concerns that arose during long-term follow-up,” study investigator Chau Dang, MD, said in presenting the findings at the European Society for Medical Oncology: Breast Cancer virtual meeting.

Dr. Dang, a medical oncologist at Memorial Sloan Kettering Cancer Centre in New York, reported that the most common cause of death was disease progression.

BERENICE was designed as a cardiac safety study and so not powered to look at long-term efficacy, which Dr. Dang was clear in reporting. Nevertheless event-free survival (EFS), invasive disease-free survival (IDFS), and overall survival (OS) rates at 5 years were all high, at least a respective 89.2%, 91%, and 93.8%, she said. “The medians have not been reached,” she observed.

“These data support the use of dual HER2 blockade with pertuzumab-trastuzumab–based regimens, including in combination with dose-dense, anthracycline-based chemotherapy, across the neoadjuvant and adjuvant treatment settings for the complete treatment of patients with HER2-positive early-stage breast cancer,” Dr. Dang said.

Evandro de Azambuja, MD, PhD, the invited discussant for the trial agreed that the regimens tested appeared “safe from a cardiac standpoint.” However, “you cannot forget that today we are using much less anthracyclines in our patient population.”

Patients in trials are also very different from those treated in clinical practice, often being younger and much fitter, he said. Therefore, it may be important to look at the baseline cardiac medications and comorbidities, Dr. de Azambuja, a medical oncologist at the Institut Jules Bordet in Brussels, Belgium, suggested.

That said, the BERENICE findings sit well with other trials that have been conducted, Dr. de Azambuja pointed out.

“If we look at other trials that have also tested dual HER2 blockade with anthracycline or nonanthracycline regimens, all of them reassure that dual blockade is not more cardiotoxic than single blockade,” he said. This includes trials such as TRYPHAENA, APHINITY, KRISTINE, NeoSphere and PEONY.

The 3-year IDFS rate of 91% in BERENICE also compares well to that seen in APHINITY (94%), Dr. de Azambuja said.
 

BERENICE study design

BERENICE was a multicenter, open-label, nonrandomized and noncomparative phase 2 trial that recruited 400 patients across 75 centers in 12 countries.

Eligibility criteria were that participants had to have been centrally confirmed HER2-positive locally advanced, inflammatory or early breast cancer, with the latter defined as tumors bigger than 2 cm or greater than 5 mm in size, and be node-positive. Patients also had to have a starting LVEF of 55% or higher.

Patients were allocated to one of two neoadjuvant chemotherapy regimens depending on the choice of their physician. One group received a regimen of dose-dense doxorubicin and cyclophosphamide (ddAC) given every 2 weeks for four cycles and then paclitaxel every week for 12 cycles. The other group received 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) every 3 weeks for four cycles and then docetaxel every 3 weeks for four cycles.

Pertuzumab and trastuzumab were started at the same time as the taxanes in both groups and given every 3 weeks for four cycles. Patients then underwent surgery and continued pertuzumab/trastuzumab treatment alone for a further 13 cycles.

The co-primary endpoints were the incidence of New York Heart Association class III or IV heart failure and incidence of symptomatic and asymptomatic LVEF decline of 10% or more.

The primary analysis of the trial was published in 2018 and, at that time, it was reported that three patients in the ddAC cohort and none in the FEC cohort experienced heart failure. LVEF decline was observed in a respective 6.5% and 2% of patients.
 

Discussion points

Dr. de Azambuja noted that the contribution of the chemotherapy to the efficacy cannot be assessed because of the nonrandomized trial design. That should not matter, pointed out Sybille Loibl, MD, PhD, during discussion.

“I think it compares nicely to other trials that looked at dose-dense chemotherapy,” said Dr. Loibl, who is an associate professor at the University of Frankfurt in Germany. “It seems that, in the light of what we consider today probably one of the best anti-HER2 treatments, the chemotherapy is less relevant, and that’s why a dose-dense regimen doesn’t add so much on a standard anthracycline taxane-containing regimen.”

Dr. de Azambuja also commented on the assessment of cardiotoxicity and the use of reduced LVEF as a measure: LVEF decline is a late effect of cardiotoxicity, he observed, and he suggested a different approach in future trials.

“If you use Global Longitudinal Strain, this could be an optimal parameter to detect early subclinical LVEF dysfunction and you should consider it for the next trials looking for cardiac safety. Also, cardiac biomarkers. This was not implemented in this trial, and I strongly recommend this should be for the next trial.”

The BERENICE trial was funded by F. Hoffmann-La Roche. Dr. Dang disclosed receiving consultancy fees from F. Hoffmann-La Roche, Genentech, Daiichi Sankyo, Lilly, and Puma Biotechnology. Dr. de Azambuja was not involved in the study but disclosed receiving honoraria, travel grants, research grants from Roche and Genentech as well as from other companies. Dr. Loibl was one of the cochairs of the session and, among disclosures regarding many other companies, has been an invited speaker for Roche and received reimbursement via her institution for a writing engagement.

Dual HER2 blockade with pertuzumab (Perjeta) and trastuzumab (Herceptin) on top of anthracycline-based neoadjuvant chemotherapy for early-stage breast cancer was associated with a low rate of clinically relevant cardiac events in the final follow-up of the BERENICE study.

After more than 5 years, 1.0%-1.5% of patients who had locally advanced, inflammatory, or early-stage breast cancer developed heart failure, and around 12%-13% showed any significant changes in left ventricular ejection fraction (LVEF).

Importantly, “there were no new safety concerns that arose during long-term follow-up,” study investigator Chau Dang, MD, said in presenting the findings at the European Society for Medical Oncology: Breast Cancer virtual meeting.

Dr. Dang, a medical oncologist at Memorial Sloan Kettering Cancer Centre in New York, reported that the most common cause of death was disease progression.

BERENICE was designed as a cardiac safety study and so not powered to look at long-term efficacy, which Dr. Dang was clear in reporting. Nevertheless event-free survival (EFS), invasive disease-free survival (IDFS), and overall survival (OS) rates at 5 years were all high, at least a respective 89.2%, 91%, and 93.8%, she said. “The medians have not been reached,” she observed.

“These data support the use of dual HER2 blockade with pertuzumab-trastuzumab–based regimens, including in combination with dose-dense, anthracycline-based chemotherapy, across the neoadjuvant and adjuvant treatment settings for the complete treatment of patients with HER2-positive early-stage breast cancer,” Dr. Dang said.

Evandro de Azambuja, MD, PhD, the invited discussant for the trial agreed that the regimens tested appeared “safe from a cardiac standpoint.” However, “you cannot forget that today we are using much less anthracyclines in our patient population.”

Patients in trials are also very different from those treated in clinical practice, often being younger and much fitter, he said. Therefore, it may be important to look at the baseline cardiac medications and comorbidities, Dr. de Azambuja, a medical oncologist at the Institut Jules Bordet in Brussels, Belgium, suggested.

That said, the BERENICE findings sit well with other trials that have been conducted, Dr. de Azambuja pointed out.

“If we look at other trials that have also tested dual HER2 blockade with anthracycline or nonanthracycline regimens, all of them reassure that dual blockade is not more cardiotoxic than single blockade,” he said. This includes trials such as TRYPHAENA, APHINITY, KRISTINE, NeoSphere and PEONY.

The 3-year IDFS rate of 91% in BERENICE also compares well to that seen in APHINITY (94%), Dr. de Azambuja said.
 

BERENICE study design

BERENICE was a multicenter, open-label, nonrandomized and noncomparative phase 2 trial that recruited 400 patients across 75 centers in 12 countries.

Eligibility criteria were that participants had to have been centrally confirmed HER2-positive locally advanced, inflammatory or early breast cancer, with the latter defined as tumors bigger than 2 cm or greater than 5 mm in size, and be node-positive. Patients also had to have a starting LVEF of 55% or higher.

Patients were allocated to one of two neoadjuvant chemotherapy regimens depending on the choice of their physician. One group received a regimen of dose-dense doxorubicin and cyclophosphamide (ddAC) given every 2 weeks for four cycles and then paclitaxel every week for 12 cycles. The other group received 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) every 3 weeks for four cycles and then docetaxel every 3 weeks for four cycles.

Pertuzumab and trastuzumab were started at the same time as the taxanes in both groups and given every 3 weeks for four cycles. Patients then underwent surgery and continued pertuzumab/trastuzumab treatment alone for a further 13 cycles.

The co-primary endpoints were the incidence of New York Heart Association class III or IV heart failure and incidence of symptomatic and asymptomatic LVEF decline of 10% or more.

The primary analysis of the trial was published in 2018 and, at that time, it was reported that three patients in the ddAC cohort and none in the FEC cohort experienced heart failure. LVEF decline was observed in a respective 6.5% and 2% of patients.
 

Discussion points

Dr. de Azambuja noted that the contribution of the chemotherapy to the efficacy cannot be assessed because of the nonrandomized trial design. That should not matter, pointed out Sybille Loibl, MD, PhD, during discussion.

“I think it compares nicely to other trials that looked at dose-dense chemotherapy,” said Dr. Loibl, who is an associate professor at the University of Frankfurt in Germany. “It seems that, in the light of what we consider today probably one of the best anti-HER2 treatments, the chemotherapy is less relevant, and that’s why a dose-dense regimen doesn’t add so much on a standard anthracycline taxane-containing regimen.”

Dr. de Azambuja also commented on the assessment of cardiotoxicity and the use of reduced LVEF as a measure: LVEF decline is a late effect of cardiotoxicity, he observed, and he suggested a different approach in future trials.

“If you use Global Longitudinal Strain, this could be an optimal parameter to detect early subclinical LVEF dysfunction and you should consider it for the next trials looking for cardiac safety. Also, cardiac biomarkers. This was not implemented in this trial, and I strongly recommend this should be for the next trial.”

The BERENICE trial was funded by F. Hoffmann-La Roche. Dr. Dang disclosed receiving consultancy fees from F. Hoffmann-La Roche, Genentech, Daiichi Sankyo, Lilly, and Puma Biotechnology. Dr. de Azambuja was not involved in the study but disclosed receiving honoraria, travel grants, research grants from Roche and Genentech as well as from other companies. Dr. Loibl was one of the cochairs of the session and, among disclosures regarding many other companies, has been an invited speaker for Roche and received reimbursement via her institution for a writing engagement.

Dual HER2 blockade with pertuzumab (Perjeta) and trastuzumab (Herceptin) on top of anthracycline-based neoadjuvant chemotherapy for early-stage breast cancer was associated with a low rate of clinically relevant cardiac events in the final follow-up of the BERENICE study.

After more than 5 years, 1.0%-1.5% of patients who had locally advanced, inflammatory, or early-stage breast cancer developed heart failure, and around 12%-13% showed any significant changes in left ventricular ejection fraction (LVEF).

Importantly, “there were no new safety concerns that arose during long-term follow-up,” study investigator Chau Dang, MD, said in presenting the findings at the European Society for Medical Oncology: Breast Cancer virtual meeting.

Dr. Dang, a medical oncologist at Memorial Sloan Kettering Cancer Centre in New York, reported that the most common cause of death was disease progression.

BERENICE was designed as a cardiac safety study and so not powered to look at long-term efficacy, which Dr. Dang was clear in reporting. Nevertheless event-free survival (EFS), invasive disease-free survival (IDFS), and overall survival (OS) rates at 5 years were all high, at least a respective 89.2%, 91%, and 93.8%, she said. “The medians have not been reached,” she observed.

“These data support the use of dual HER2 blockade with pertuzumab-trastuzumab–based regimens, including in combination with dose-dense, anthracycline-based chemotherapy, across the neoadjuvant and adjuvant treatment settings for the complete treatment of patients with HER2-positive early-stage breast cancer,” Dr. Dang said.

Evandro de Azambuja, MD, PhD, the invited discussant for the trial agreed that the regimens tested appeared “safe from a cardiac standpoint.” However, “you cannot forget that today we are using much less anthracyclines in our patient population.”

Patients in trials are also very different from those treated in clinical practice, often being younger and much fitter, he said. Therefore, it may be important to look at the baseline cardiac medications and comorbidities, Dr. de Azambuja, a medical oncologist at the Institut Jules Bordet in Brussels, Belgium, suggested.

That said, the BERENICE findings sit well with other trials that have been conducted, Dr. de Azambuja pointed out.

“If we look at other trials that have also tested dual HER2 blockade with anthracycline or nonanthracycline regimens, all of them reassure that dual blockade is not more cardiotoxic than single blockade,” he said. This includes trials such as TRYPHAENA, APHINITY, KRISTINE, NeoSphere and PEONY.

The 3-year IDFS rate of 91% in BERENICE also compares well to that seen in APHINITY (94%), Dr. de Azambuja said.
 

BERENICE study design

BERENICE was a multicenter, open-label, nonrandomized and noncomparative phase 2 trial that recruited 400 patients across 75 centers in 12 countries.

Eligibility criteria were that participants had to have been centrally confirmed HER2-positive locally advanced, inflammatory or early breast cancer, with the latter defined as tumors bigger than 2 cm or greater than 5 mm in size, and be node-positive. Patients also had to have a starting LVEF of 55% or higher.

Patients were allocated to one of two neoadjuvant chemotherapy regimens depending on the choice of their physician. One group received a regimen of dose-dense doxorubicin and cyclophosphamide (ddAC) given every 2 weeks for four cycles and then paclitaxel every week for 12 cycles. The other group received 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) every 3 weeks for four cycles and then docetaxel every 3 weeks for four cycles.

Pertuzumab and trastuzumab were started at the same time as the taxanes in both groups and given every 3 weeks for four cycles. Patients then underwent surgery and continued pertuzumab/trastuzumab treatment alone for a further 13 cycles.

The co-primary endpoints were the incidence of New York Heart Association class III or IV heart failure and incidence of symptomatic and asymptomatic LVEF decline of 10% or more.

The primary analysis of the trial was published in 2018 and, at that time, it was reported that three patients in the ddAC cohort and none in the FEC cohort experienced heart failure. LVEF decline was observed in a respective 6.5% and 2% of patients.
 

Discussion points

Dr. de Azambuja noted that the contribution of the chemotherapy to the efficacy cannot be assessed because of the nonrandomized trial design. That should not matter, pointed out Sybille Loibl, MD, PhD, during discussion.

“I think it compares nicely to other trials that looked at dose-dense chemotherapy,” said Dr. Loibl, who is an associate professor at the University of Frankfurt in Germany. “It seems that, in the light of what we consider today probably one of the best anti-HER2 treatments, the chemotherapy is less relevant, and that’s why a dose-dense regimen doesn’t add so much on a standard anthracycline taxane-containing regimen.”

Dr. de Azambuja also commented on the assessment of cardiotoxicity and the use of reduced LVEF as a measure: LVEF decline is a late effect of cardiotoxicity, he observed, and he suggested a different approach in future trials.

“If you use Global Longitudinal Strain, this could be an optimal parameter to detect early subclinical LVEF dysfunction and you should consider it for the next trials looking for cardiac safety. Also, cardiac biomarkers. This was not implemented in this trial, and I strongly recommend this should be for the next trial.”

The BERENICE trial was funded by F. Hoffmann-La Roche. Dr. Dang disclosed receiving consultancy fees from F. Hoffmann-La Roche, Genentech, Daiichi Sankyo, Lilly, and Puma Biotechnology. Dr. de Azambuja was not involved in the study but disclosed receiving honoraria, travel grants, research grants from Roche and Genentech as well as from other companies. Dr. Loibl was one of the cochairs of the session and, among disclosures regarding many other companies, has been an invited speaker for Roche and received reimbursement via her institution for a writing engagement.