Primary results and characterization of patients with exceptional outcomes in a phase 1b study combining PARP and MEK inhibition, with or without anti–PD‐L1, for BRCA wild‐type, platinum‐sensitive, recurrent ovarian cancer

Background This phase 1b study (ClinicalTrials.gov identifier NCT03695380) evaluated regimens combining PARP and MEK inhibition, with or without PD‐L1 inhibition, for BRCA wild‐type, platinum‐sensitive, recurrent ovarian cancer (PSROC). Methods Patients with PSROC who had received one or two prior treatment lines were treated with 28‐day cycles of cobimetinib 60 mg daily (days 1–21) plus niraparib 200 mg daily (days 1–28) with or without atezolizumab 840 mg (days 1 and 15). Stage 1 assessed safety before expansion to stage 2, which randomized patients who had BRCA wild‐type PSROC to receive either doublet or triplet therapy, stratified by genome‐wide loss of heterozygosity status (