ASCO 2021: OlympiA Trial of Adjuvant Olaparib After Chemotherapy for Early-Stage Breast Cancer
Posted: Friday, June 4, 2021
Adjuvant treatment with the PARP inhibitor olaparib seemed to significantly improve invasive disease– and distant disease–free survival outcomes with acceptable toxicity in patients with germline BRCA1/2-mutated and high-risk HER2-negative early-stage breast cancer who underwent chemotherapy. These interim results from the multicenter phase III OlympiA trial were presented by Andrew Tutt, PhD, MB, ChB, of The Institute of Cancer Research, London, and colleagues during a presscast in advance of the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract LBA1, Plenary).
“OlympiA’s findings highlight the need for genetic testing for BRCA mutations in patients diagnosed with high-risk early-stage breast cancer, said ASCO President Lori J. Pierce, MD, FASTRO, FASCO, in an ASCO press release. “These results could have an important impact on treatment decisions for this patient population, possibly including the use of a PARP inhibitor in the adjuvant setting.”
A total of 1,836 patients who underwent primary local treatment and adjuvant or neoadjuvant chemotherapy were randomly assigned in a 1:1 ratio to receive oral olaparib or a placebo. Interim follow-up data were provided for a median of 2.5 years.
Olaparib seemed to significantly improve invasive disease–free survival, compared with the placebo (hazard ratio = 0.58; P < .0001). The 3-year invasive disease–free survival rate was 85.9% with olaparib and 77.1% with the placebo. Distant disease–free survival also seemed to significantly improve with olaparib, compared with the placebo (hazard ratio = 0.57; P < .0001). The rates of distant disease–free survival were 87.5% and 80.4% with olaparib and the placebo, respectively, at 3 years. The duration of overall survival was longer with olaparib than with the placebo (hazard ratio = 0.68); however, this difference was not statistically significant (P = .024). At 3 years, the overall survival rate was 92.0% with olaparib and 88.3% with the placebo.
Anemia (8.7%), neutropenia (4.8%), leukopenia (3.0%), fatigue (1.8%), and lymphocytopenia (1.2%) were among the most commonly reported grade 3 or higher adverse events with olaparib. Treatment with olaparib were not found to increase the rates of serious adverse events (8.7% vs. 8.4%) and adverse events of special interest (2.6% vs. 4.6%), compared with the placebo.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.