AT the 2024 San Antonio Breast Cancer Symposium (SABCS), new Phase III trial data presented the promising results of imlunestrant, an oral next-generation selective estrogen receptor degrader (SERD), in patients with advanced breast cancer. The study demonstrated significant improvements in progression-free survival for patients with ESR1-mutated, ER-positive, HER2-negative breast cancer—both as a monotherapy and in combination with abemaciclib.
The EMBER-3 trial, involving 874 patients with advanced breast cancer who had progressed on prior endocrine therapy, showed that imlunestrant reduced the risk of progression or death by 38% in patients with ESR1 mutations. In the overall patient population, however, the improvement was not statistically significant compared to standard endocrine therapy.
Additionally, when combined with abemaciclib, imlunestrant reduced the risk of progression or death by 43%, with a median progression-free survival of 9.4 months for the combination therapy, versus 5.5 months for monotherapy. Notably, this benefit was observed across all patient subgroups, including those with and without ESR1 mutations.
Imlunestrant also demonstrated a favorable safety profile, with manageable side effects and no major safety signals typically associated with oral SERDs. The all-oral regimen offers significant convenience compared to current therapies like fulvestrant, which requires intramuscular injections.
These findings suggest that imlunestrant could offer an effective and well-tolerated treatment option for patients with advanced breast cancer who have developed resistance to standard hormone therapies.
Reference: San Antonio Breast Cancer Symposium. (2024, December 11). Next-generation SERD Protects Against Progression in Some Patients With Advanced Breast Cancer Resistant to Standard Hormone Therapy. Presented at SABCS 2024.
Anaya Malik | AMJ
