The iPRIME study, a randomized non-comparative phase 2 trial in advanced high-grade serous ovarian cancer, reported that adding durvalumab plus tremelimumab to standard neoadjuvant chemotherapy did not meet the study’s primary chemotherapy response endpoint. Radiologic response rates were similar between arms. The regimen—Du-T-NACT—was evaluated in newly diagnosed FIGO stage IIIC/IV patients, with the primary measure defined as CRS 3 after three cycles. The experimental arm’s CRS 3 rate did not reach the pre-specified threshold. The data weigh on expectations for dual checkpoint blockade in this setting and reinforce the need for more discriminating biomarkers or alternative immunotherapy combinations.