Lidia Trombello, Marie curie PhD fellow at the Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), shared on LinkedIn:
“ESMO 2026 Update: Phase III postMONARCH Overall Survival Results
Live from Madrid at ESMO26! Today during the Rapid Oral session (Breast Advanced), Dr. Kevin Kalinsky presented the final Overall Survival (OS) data from the Phase III postMONARCH trial evaluating abemaciclib plus fulvestrant versus placebo plus fulvestrant in patients with HR+, HER2- advanced breast cancer following progression on a prior CDK4/6 inhibitor plus endocrine therapy.
Here are the key takeaways:
Overall Survival Results:
Median OS numerically favored abemaciclib + fulvestrant: 32.1 months vs. 24.6 months (Δ7.5 months; HR 0.80, 95% CI 0.60–1.06). Although the difference did not reach statistical significance, it showed a numerical 20% reduction in the risk of death.
OS results were consistent across prespecified subgroups, including prior CDK4/6i duration.
Efficacy Trends and Subsequent Therapies:
Both PFS2 and Time to Chemotherapy (TTC) favored the abemaciclib + fulvestrant combination.
Subsequent anti-cancer therapies were well-balanced across study arms.
Safety Profile:
The updated safety profile remains consistent with the known safety profile of abemaciclib, with no new safety signals identified.
Conclusion:
Together, these data continue to support the consideration of abemaciclib-based treatments after progression on a prior CDK4/6 inhibitor.
Proud to share these key advances in breast cancer care for OncoDaily !
Session: Rapid Oral – Breast Advanced
Speaker: Dr. Kevin Kalinsky (Winship Cancer Institute, Emory University).”
You can also read: 20 Posts Not to Miss from ESMO Congress 2026: Day 2
