For a study, researchers sought to understand that TRAMUNE was a phase Ib study that combines trabectedin with durvalumab and includes a dose-escalation phase and 2 expansion cohorts, soft tissue sarcoma (STS) and ovarian carcinoma. Trabectedin was administered in 3 dose levels (1 mg/m2, 1.2 mg/m2, and 1.5 mg/m2) on day 1 in combination with durvalumab, followed by 1,120 mg on day 2 every 3 weeks. The primary endpoints were the recommended phase II dose (RP2D) of trabectedin combined with durvalumab and the RECIST 1.1 objective response rate (ORR). The secondary endpoints were safety, 6-month progression-free rate (PFR), progression-free survival (PFS), overall survival, and biomarker analyses. A total of 40 patients were included in the study (n=9 for dose escalation, 16 for STS, and n=15 for ovarian carcinoma, with an 80% platinum resistance/refractory rate). The most common toxicities were grade 1-2 fatigue, nausea, neutropenia, and an increase in alanine/aspartate aminotransferase. At dose level 2, 1 patient experienced dose-limiting toxicity. Trabectedin was chosen as the RP2D at 1.2 mg/m2. In the STS cohort, 43% of patients had tumor shrinkage, the ORR was 7% [95% CI, 0.2–33.9], and the 6-month PFR was 28.6% (95% CI, 8.4–58.1). In the ovarian carcinoma cohort, 43% of patients had tumor shrinkage, 21.4% had ORR (95% CI, 4.7–50.8), and 42.9% had 6-month PFR (95% CI, 17.7–71.1). In patients with ovarian carcinoma, baseline levels of programmed death-ligand 1 expression and CD8-positive T-cell infiltrates were associated with PFS. The combination of trabectedin and durvalumab was tolerable. Patients with platinum-refractory ovarian cancer have shown promising activity.