Phase 1 trial of concurrent olaparib and radiotherapy for triple-negative breast cancer

Triple-negative breast cancer (TNBC) cells are sensitive to PARP inhibitors used as radiosensitizers. The phase 1 RadioPARP trial at the Institut Curie (Paris, France) evaluated concurrent olaparib and radiotherapy for TNBC with residual disease after neoadjuvant chemotherapy. There were no olaparib dose-limiting effects and no late treatment-related grade 3 or greater toxic effects. Three-year EFS and OS were 65% (95% CI 48-88) and 83% (95% CI 70-100),respectively. Homologous recombination status was not associated with EFS or OS. The authors conclude that concurrent olaparib and radiotherapy for early-stage, high-risk TNBC should continue to be evaluated in further clinical trials.