Adjuvant Therapy in BRCA-Positive Breast Cancer: Olaparib vs CDK4/6 Inhibitors

Olaparib in Metastatic and Adjuvant Settings

In BRCA-positive breast cancer, we have two approved treatments: olaparib and talazoparib. Olaparib has been used for over a decade in the metastatic setting, with talazoparib added based on the BRCA and OLYMPIA trials. Recently at the San Antonio 2024 meeting, an eight-year follow-up of the adjuvant olaparib trial provided encouraging results.

The study demonstrated that the survival benefit observed early on continued even after seven to eight years of follow-up. This advantage applies to both ER-negative and ER-positive patients, although with different entry criteria. In triple-negative breast cancer, any lymph node positivity qualifies for the trial, while in ER-positive breast cancer, four or more positive nodes are required, or residual disease after neoadjuvant therapy.

Adjuvant Olaparib vs CDK4/6 Inhibitors

The emergence of effective CDK4/6 inhibitors like abemaciclib and ribociclib adds another layer to treatment decisions. These agents have demonstrated efficacy in both adjuvant and metastatic settings, raising the question of whether to choose olaparib or CDK4/6 inhibitors in BRCA-positive patients.

The current recommendation is to sequence these therapies rather than combine them. The choice depends on factors like duration of treatment (olaparib: 1 year vs. abemaciclib and ribociclib: 2-3 years) and individual patient characteristics. When considering survival advantage, olaparib remains a strong option for patients eligible for adjuvant therapy.