Early Results for Novel Combination in Metastatic Breast Cancer
Posted: Friday, July 23, 2021
AMEERA-1 is a phase I/II study including evaluation of amcenestrant plus palbociclib in postmenopausal women with estrogen receptor–positive/HER2-negative metastatic breast cancer. Preliminary data on the combination’s antitumor activity at the recommended phase II dose were reported during the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 1058). Amcenestrant is an oral selective estrogen receptor degrader, and the overall response to the combination after at least six cycles was 31.4%, with a clinical benefit rate of 74.3%, according to Sarat Chandarlapaty, MD, PhD, of Memorial Sloan Kettering Cancer Center, New York, and colleagues.
In this population, at the recommended phase II dose of 200 mg of amcenestrant daily, the safety profile was considered to be favorable by the study investigators, with no bradycardia or eye disorders. The targeted therapy palbociclib was given at 125 mg daily for 21 days on/7 days off. All patients had disease that was resistant to prior endocrine therapy. The pooled safety population at the recommended phase II dose included 39 women, with a median age of 59 years (range, 33–86 years).
The most common nonhematologic treatment-emergent adverse events related to amcenestrant were grade 1 or 2 nausea and fatigue (17.9% each) and asthenia and hot flush (10.3% each). Those related to palbociclib were fatigue (30.8%), nausea (25.6%), asthenia, and dysgeusia (10.3% each). Almost all patients (94.9%) had neutrophil count decrease, with 53.8% grade ≥ 3. However, no amcenestrant dose reductions occurred. About one-quarter of patients had one or more palbociclib dose reductions, and two patients discontinued treatment due to adverse events.
Disclosure: The study authors’ disclosure information can be found at coi.asco.org.
