Nivolumab (NIVO) plus ipilimumab (IPI) combination therapy in patients (Pts) with advanced hepatocellular carcinoma (aHCC): Long-term results from CheckMate 040.

269 Background: NIVO 1 mg/kg + IPI 3 mg/kg Q3W (4 doses) followed by NIVO 240 mg Q2W is approved in the US for sorafenib-treated pts with aHCC based on initial results from CheckMate 040 (NCT01658878), which reported objective response rate (ORR) of 32% and median overall survival (mOS) of 22.8 months (mo). 1 We present 44-mo long-term follow-up results from the CheckMate 040 NIVO+IPI cohort. Methods: Pts were randomized to 3 arms: [A] NIVO 1 mg/kg + IPI 3 mg/kg Q3W (4 doses) or [B] NIVO 3 mg/kg + IPI 1 mg/kg Q3W (4 doses), each followed by NIVO 240 mg Q2W, or [C] NIVO 3 mg/kg Q2W + IPI 1 mg/kg Q6W. Treatment continued until intolerable toxicity or disease progression. Safety and tolerability, ORR (blinded independent central review per RECIST v1.1), duration of response (DOR), disease control rate (DCR), and OS were assessed. Data cutoff was May 26, 2020. Results: 148 pts were randomized. Minimum follow-up was 44 mo. mOS remained at 22.2 mo in arm A, 12.5 mo in arm B, and 12.7 mo in arm C; 36-mo OS rates were 42%, 26%, and 30%, respectively. Durable responses were achieved across treatment arms, with DOR approaching 4 years in some cases. DCR was higher in arm A than arms B and C. In all arms, responses were observed regardless of baseline programmed death ligand 1 expression ( < 1% or ≥ 1%) or baseline alpha-fetoprotein level ( < 400 µg/L or ≥ 400 µg/L). Pts with hepatitis B or C virus (HBV or HCV) etiology had higher ORR than uninfected pts in arms B (29% vs 43% vs 9%) and C (31% vs 42% vs 0%). ORR was independent of etiology in arm A (HBV, 32%; HCV, 29%; uninfected, 31%). Additional efficacy data are in the table. There were no additional discontinuations due to treatment-related adverse events or immune-mediated adverse events (IMAEs) since the primary analysis. IMAEs were reported more frequently in arm A than arms B and C; the most common were rash, hepatitis, and adrenal insufficiency. Most IMAEs were reversible and resolved when treated using established algorithms. Conclusions: At a minimum follow-up of 44 mo, second-line NIVO1+IPI3 continued to demonstrate clinically meaningful responses and long-term survival benefit in aHCC. The safety profile was manageable and no new safety signals were identified with longer follow-up. Clinical trial information: NCT01658878. [Table: see text]