A Randomized Study Comparing the Immune Modulation Effect of Ribociclib, Palbociclib, and Abemaciclib in ER+/HER2- EBC
Status:
Recruiting
Trial end date:
2026-09-30
Target enrollment:
Participant gender:
Summary
The 3 FDA-approved CDK4, 6 inhibitors, palbociclib, ribociclib, and abemciclib, all provided
progression-free survival benefits when combined with endocrine therapy in advanced ER+/HER2-
breast cancer. But, not all of them provided overall survival benefit in the same setting.
One of the proposed mechanisms that influence the overall survival difference is from the
different influence of the 3 CDK4, 6 inhibitors on tumor microenvironment and/ or immune
system. However, there was no head-to-head comparison of the 3 CDK4, 6 inhibitors in the same
study. Neoadjuvant therapy provides a window to obtain tissue samples before treatment,
during treatment, and after treatment. We aim to compare the immune modulation effects of
palbociclib, ribociclib, and abemaciclib with letrozole in neoadjuvant treatment for
ER+/HER2- early breast cancer.