Amcenestrant was an oral drug developed to treat certain types of breast cancer. It belonged to a class of medications known as selective estrogen receptor degraders (SERDs). Its clinical development program has since been discontinued.
Understanding Amcenestrant
Amcenestrant was an oral selective estrogen receptor degrader (SERD) developed for estrogen receptor-positive (ER+) breast cancer. This specific type of cancer is characterized by estrogen receptors on cell surfaces. These receptors allow estrogen to bind and stimulate cell growth.
The drug was primarily developed to treat hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer.
How Amcenestrant Targets Cancer
Estrogen receptors are proteins inside breast cancer cells that, when activated by estrogen, promote tumor growth. Amcenestrant was designed to bind to these estrogen receptors. By binding, it would block estrogen attachment and trigger receptor degradation.
This dual action aimed to significantly reduce the number of active estrogen receptors within cancer cells. With fewer functional receptors, estrogen’s ability to stimulate cell division and tumor progression would be diminished. The intent was to halt or slow the growth of estrogen-driven breast cancers.
Current Research and Patient Outlook
Amcenestrant was an investigational drug that progressed through various phases of clinical trials, including Phase 2 and Phase 3 studies. These trials aimed to assess its effectiveness and safety, both as a standalone treatment and in combination with other therapies like palbociclib. For instance, the AMEERA-5 trial investigated amcenestrant combined with palbociclib as a first-line treatment for ER+/HER2- advanced breast cancer.
The global clinical development program for amcenestrant has been discontinued. This decision was made following an interim analysis of the Phase 3 AMEERA-5 trial, which indicated that the combination of amcenestrant and palbociclib did not meet its primary objective of improving progression-free survival compared to the control arm. While the discontinuance of amcenestrant means it will not be available as a new oral SERD option, other oral SERDs continue to be developed, offering continued hope for patients.
Side Effects and Safety Profile
During its clinical trials, amcenestrant’s safety profile was continuously monitored. Common treatment-emergent adverse events of any grade were observed in a significant percentage of patients, with some experiencing more severe, Grade 3 or higher, events. While specific details of every side effect are extensive, these observations are typical for drugs in development, and the overall safety profile was part of the ongoing evaluation. The discontinuation of the development program means a complete long-term safety profile is not fully established for patient use.