GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE344nnn/GSE344584/primaryOK200OtherHomo sapiensOtherhttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE344584GEOGSEfalseOlaparib plus tremelimumab in women with recurrent ovarian cancer and a germline BRCA1 or BRCA2 mutation: a phase I/II studyResponse rates to immune checkpoint blockade (ICB) in ovarian cancer are low. In preclinical studies, poly(ADP-ribose) polymerase (PARP) inhibition synergized with CTLA4 ICB to achieve long-term survival in Brca1-deficient ovarian cancer models. Here, we evaluated the safety and efficacy of combined treatment with the PARP inhibitor olaparib and the CTLA4 ICB tremelimumab for recurrent epithelial ovarian cancer in a multi-site single-arm phase I/II study enrolling 50 women with a germline BRCA1 or BRCA2 mutation (NCT0257125). Grade 3 or 4 non-hematologic toxicity was reported in 57% of subjects, with tremelimumab discontinuation in 34.7%. The overall response rate was 32.7% (95% CI 19.5-45.8%), with a disease control rate of 47.7% (95% CI 33.0-62.5%). In exploratory biomarker analyses, low VSTM5 or IFIT1B expression was associated with treatment benefit and progression-free survival (p<0.001). Although this trial did not meet its prespecified efficacy endpoint, durable responses in some subjects in this heavily pre-treated cohort highlight the need for predictive biomarkers to select combinatorial regimens for patients with recurrent ovarian cancer.2026/08/27GSE344584GSM9981854GSM9981855GSM9981856GSM9981860GSM9981861GSM9981857GSM9981858GSM998185933762344584Homo sapiens