Shares of Sanofi took a hit in premarket trading after it announced its Phase II breast cancer study assessing an experimental oral SERD failed to hit the mark.
Pat Greenhouse/The Boston Globe via Getty
Shares of Sanofi took a hit in premarket trading this morning after the company announced its Phase II breast cancer study assessing an experimental oral selective estrogen receptor degrader (SERD) failed to hit the mark. The investigational drug has been seen as a cornerstone for Sanofi’s future oncology pipeline. Shares were down as much as 5% in premarket trading and remained down more than 1% after the opening bell.
Sanofi reported that amcenestrant did not meet its primary endpoint of improving progression-free survival in the Phase II AMEERA-3 trial in patients with locally advanced or metastatic estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer. In the study, amcenestrant was being assessed as a monotherapy compared to endocrine treatment of physician’s choice.
The primary endpoint of AMEERA-3 was progression-free survival compared to endocrine monotherapy. The key secondary endpoint was overall survival. Other secondary endpoints included objective response rate, disease control rate, clinical benefit rate and duration of response.
Full results from the study were not immediately available. Sanofi will continue to assess the study data and share those results at a later date. The safety profile of amcenestrant remained consistent with data from other studies.
Although AMEERA-3 failed to hit the mark, Sanofi will continue to investigate amcenestrant in breast cancer with other ongoing studies, including AMEERA-5 and AMEERA-6.
John Reed, Sanofi’s head of research and development, said the Phase II study of amcenestrant was in a breast cancer patient population with limited treatment options. The study was comprised of patients whose cancer had progressed during or following hormonal therapy treatments.
“While we are disappointed with the AMEERA-3 results, we continue to investigate amcenestrant in patients with earlier stages of breast cancer with different tumor profiles and where different standard of care treatments are used,” Reed said in a statement.
Amcenestrant is an optimized oral SERD designed to bind to the estrogen receptors (ER) in breast cancer cells in order to constrain their normal function and trigger degradation so they can no longer be used by tumor cells to grow. Sanofi has had high hopes for amcenestrant.
Last year, ahead of the annual meeting of the American Society of Clinical Oncology Peter Adamson, Sanofi’s global development head of oncology at Sanofi, predicted that amcenestrant could be a backbone therapy for ER+ breast cancer based on early data seen in other studies, including one that was combined with Pfizer‘s Ibrance.
The Phase III AMEERA-6 study is being conducted in partnership with the Breast International Group (BIG), the European Organization for Research and Treatment of Cancer (EORTC) and Alliance Foundation Trials (AFT). That study is focused on ER+ breast cancer patients who have prematurely discontinued standard adjuvant aromatase inhibitor (AI) therapy and have a high risk of disease recurrence. Sanofi is expected to be the first pivotal trial of an oral SERD in the adjuvant setting. The study is now enrolling patients.
In its coverage of the AMEERA-3 failure, Reuters cited analysts from J.P. Morgan who suggested that the disappointing results from this study may raise concern from investors over the company’s oncology pipeline. Regarding the other ongoing AMEERA trials, the analysts said the AMEERA-3 failure is likely to “increase the risk in investors’ minds.”
