Phase 3 randomized, open-label, multicenter study of tremelimumab (T) and durvalumab (D) as first-line therapy in patients (pts) with unresectable hepatocellular carcinoma (uHCC): HIMALAYA.

HIMALAYA is an open-label, multicenter, phase 3 study, in which pts with uHCC and no prior systemic therapy were initially randomized to STRIDE (T 300 mg plus D 1500 mg [one dose] plus D 1500 mg every 4 weeks [Q4W]), D (1500 mg Q4W), S (400 mg twice daily), or T 75 mg Q4W (4 doses) plus D 1500 mg Q4W (T75+D). Recruitment to T75+D ceased after a planned analysis of Study 22 showed T75+D did not meaningfully differ from D. The primary objective was overall survival (OS) for STRIDE vs S. The secondary objective was OS noninferiority (NI) of D to S (NI margin: 1.08). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR; RECIST v.1.1), duration of response (DoR), and safety.

In total, 1171 pts were randomized to STRIDE (N=393), D (N=389), or S (N=389). At data cutoff (DCO), the primary objective was met: OS was significantly improved for STRIDE vs S (hazard ratio [HR], 0.78; 96% confidence interval [CI], 0.65–0.92; p=0.0035; Table). D met the objective of OS NI to S (HR, 0.86; 96% CI, 0.73–1.03). ORRs were higher for STRIDE (20.1%) and D (17.0%) than for S (5.1%). No new safety signals were identified. Grade 3/4 treatment-related adverse events (TRAEs) occurred in 25.8% (STRIDE), 12.9% (D), and 36.9% (S) of pts. Grade 3/4 hepatic TRAEs occurred in 5.9% (STRIDE), 5.2% (D), and 4.5% (S) of pts. No TRAE of esophageal varices hemorrhage occurred. Rates of TRAEs leading to discontinuation were 8.2% (STRIDE), 4.1% (D), and 11.0% (S).