Elacestrant Plus Abemaciclib Shows Promise in Advanced Breast Cancer Treatment
A recent analysis of clinical trials presents encouraging results for the combination of elacestrant (Orserdu) and abemaciclib (Verzenio) in treating patients with advanced or metastatic estrogen receptor (ER)-positive/HER2-negative breast cancer.
Clinical Benefits and Safety Profile
The pooled data from the phase 1b portion of the ELECTRA (NCT05386108) and arm C of the phase 2 ELEVATE (NCT05563220) studies, presented at the 2024 San Antonio Breast Cancer Symposium, revealed significant clinical benefits with an acceptable safety profile.
The objective response rate (ORR) in patients who received elacestrant at a daily dose of 345 mg plus abemaciclib at 150 mg twice daily (n = 38) was 18%, including a complete response (CR) rate of 5% and a partial response (PR) rate of 13%. Notably, a stable disease (SD) rate of 66% was observed, with 16% of patients experiencing disease progression. The clinical benefit rate (CBR) was 84%.
The primary endpoint for this combination is progression-free survival (PFS), but investigators acknowledge that the median PFS was not yet reached in arm C of the ELEVATE study (n = 26) due to the average observation time not being achieved at 24 weeks.
Importantly, the most common treatment-emergent adverse effects (AEs) experienced by 20% or more of patients were diarrhea, nausea, vomiting, fatigue, neutropenia, anemia, constipation, and reduced appetite. Sed attractively detailed and comprehensive. Notably, no grade 4 AEs were observed during the treatment period.
Target Patient Population and Treatment Resistance
This combination therapy targets ER-positive/HER2-negative metastatic breast cancer patients who have progressed through previous endocrine therapy and CDK4/6 inhibitors. These patients often experience disease resistance due to alterations in cancer cell cycle pathways, the PI3K/AKT/mTOR pathway, or acquired ESR1 mutations.
Investigators hypothesized that elacestrant plus abemaciclib could address these resistance mechanisms, providing a novel and effective treatment option.
Ongoing Research and Future Directions
The phase 2 portion of the ELECTRA study examining elacestrant at a once-daily dose of 345 mg with abemaciclib at a twice-daily dose of 150 mg is ongoing. This research aims to further evaluate its efficacy and safety in a larger patient population.
Interested readers are encouraged to consult with their healthcare providers to learn more about potential treatment options and explore whether elacestrant plus abemaciclib could be a suitable therapy for their individual situation.