In the second interim analysis of the OlympiA trial the PARP inhibitor olaparib as adjuvant therapy confirms significant improvement in invasive-disease-free survival and distant-disease-free survival for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, HER2-negative, early breast cancer; the results, recently published in Annals of Oncology, also show an improvement in overall survival with no new safety signals.
For the randomized, double-blind OlympiA trial, 1836 patients with gBRCA1/2pv early breast cancer were randomly assigned to one year olaparib or placebo following neoadjuvant chemotherapy, surgery, and radiation therapy if indicated. The first interim analysis previously demonstrated statistically significant improvement in invasive-disease-free survival and distant-disease-free survival; now, after a median follow-up of 3.5 years, this second interim analysis demonstrated significant an improvement in the olaparib-group relative to the placebo-group. Four-year overall survival was 89.8% in the olaparib-group and 86.4% in the placebo-group; four-year invasive-disease-free survival for olaparib-group versus placebo-group was 82.7% versus 75.4% and 4-year distant-disease-free survival was 86.5% versus 79.1%, with benefits demonstrated across major subgroups of patients and no new safety signals. «The results highlight the importance of testing for gBRCA1/2pv in patients with newly diagnosed high-risk early breast cancer. Blinded follow-up of patients continues to assess long-term effects on risks for recurrent breast cancer and other second malignancies, as well as to fully inform future translational studies to understand mechanisms of resistance to adjuvant olaparib», authors conclude.