Clinical effectiveness of olaparib monotherapy in germline BRCA-mutated, HER2-negative metastatic breast cancer in a real-world setting: phase IIIb LUCY interim analysis

•LUCY was a phase IIIb trial of the PARP inhibitor olaparib.•LUCY followed the phase III OlympiAD trial and aimed to reflect clinical practice.•Investigator-assessed progression-free survival was 8.11 months (65.9% maturity).•Grade ≥3 TEAEs occurred in 64 patients (25.4%), including anaemia in 33 patients.•These interim results support previous findings from the OlympiAD trial.