A phase 2 iPRIME study reported that neoadjuvant durvalumab plus tremelimumab added to standard chemotherapy did not meet its primary efficacy endpoint in advanced high-grade serous ovarian cancer. In the Du-T-NACT arm, the rate of CRS 3 after three cycles was 32.5% (90% CI 20%–47%), with no statistically significant improvement versus chemotherapy alone on response measures such as RECIST 1.1.