On March 11, 2022, the FDA accelerated the approval of the oral PARP inhibitor olaparib (Lynparza; AstraZeneca) for the adjuvant treatment of adults with HER2-negative, high-risk early breast cancer and deleterious or suspected deleterious germline BRCA mutation after neoadjuvant or adjuvant chemotherapy. Patients must be selected for olaparib therapy for this indication based on an FDA-approved test.
This approval was based on the OlympiA study, a randomized (1:1), double-blind, placebo-controlled, international clinical trial of 1836 patients with HER2-negative, high-risk early breast cancer and germline BRCA mutation who completed definitive local treatment and neoadjuvant or adjuvant chemotherapy. Patients were randomized to 1 year of olaparib 300 mg orally twice daily or to placebo. Patients had to have completed ≥6 cycles of neoadjuvant or adjuvant chemotherapy containing anthracyclines, taxanes, or both. Patients with hormone receptor–positive breast cancer were allowed to continue concurrent treatment with endocrine therapy.
The primary efficacy end point was invasive disease-free survival (IDFS), defined as the time from randomization to the date of first recurrence (ie, invasive locoregional or distant recurrence), contralateral invasive breast cancer, new cancer, or death from any cause.
At a prespecified interim analysis at a median follow-up of 2.5 years, the 3 years IDFS rate was 85.9% in the olaparib arm versus 77.1% in the placebo arm, amounting to 8.8% difference (95% confidence interval [CI], 4.5-13.0) and a hazard ratio (HR) of 0.58 for invasive disease or death (99.5% CI, 0.41-0.82; P <.0001). A total of 56 deaths were reported in the olaparib arm and 86 in the placebo arm, but the difference was not statistically significant (HR, 0.68; 99% CI, 0.44-1.05; P = .02).
The most common (≥10%) adverse reactions in this study were nausea, fatigue (including asthenia), anemia, vomiting, headache, diarrhea, leukopenia, neutropenia, decreased appetite, dysgeusia, dizziness, and stomatitis.
