Durvalumab with or without tremelimumab plus chemotherapy in HRR non-mutated, platinum-resistant ovarian cancer (KGOG 3045): A phase II umbrella trial

•Efficacy and safety of chemotherapy plus durvalumab with or without tremelimumab were studied in PROC without HRR mutation.•Addition of tremelimumab improved progression-free survival on multivariable Cox HR analysis.•Biomarkers were explored with immunohistochemistry and whole-exome and transcriptome sequencing.•Mutation in MUC16 and high EPCAM were associated with favorable response in the overall cohort.•Arm-specific biomarker in tremelimumab group were EPCAM expression and matrix remodeling score.