Randomised efficacy and safety results for atezolizumab (Atezo) + bevacizumab (Bev) in patients (pts) with previously untreated, unresectable hepatocellular carcinoma (HCC)

Abstract

Background: Pts with unresectable HCC have few treatment (tx) options. Checkpoint inhibitors and combination approaches with anti-VEGFs are emerging as potential new tx options. Here we report the first randomised dataset evaluating atezo (anti-PDL1) as monotherapy vs the combination of atezo + bev (anti-VEGF; Arm F) as well as updated single-arm atezo + bev data (Arm A) from a Ph 1b study. Methods: Arms F and A of the Ph 1b study GO30140 enrolled systemic tx-naïve pts with unresectable HCC. Arm F pts were randomised 1:1 to atezo + bev or atezo monotherapy and received atezo 1200 mg IV q3w, bev 15 mg/kg IV q3w until unacceptable toxicity or loss of clinical benefit. Arm A pts received atezo + bev. Primary endpoints were progression free survival (PFS; Arm F) and objective response rate (ORR, Arm A) by independent review facility (IRF)-assessed RECIST 1.1, and safety (Arms F and A). Results: In Arm F, 60 pts were randomised to atezo +bev (Group F1) and 59 pts to atezo (Group F2). Arm F showed a statistically significant improvement in the primary endpoint median PFS for atezo + bev vs atezo (5.6 vs 3.4mo, HR 0.55, 80% CI, 0.40 -0.74, P=0.0108). Any-Gr TRAEs occurred in 41 (68%) F1 pts and 24 (41%) F2 pts; Gr 3-4 TRAEs occurred in 12 (20%) F1 pts and 3 (5%) F2 pts. There were no Gr 5 TRAEs in Arm F. For the 104 pts in Arm A, primary endpoint ORR was 36% (37 pts) with 76% ongoing. Any-Grade (Gr) tx-related adverse events (TRAEs) occurred in 91 (88%) pts; Gr 3-4 TRAEs occurred in 41 (39%) pts. Gr 5 TRAEs were seen in 3 (3%) pts. Conclusions: By meeting its primary endpoint of improved PFS for atezo + bev vs atezo alone, Arm F showed the single-agent contribution of atezo and bev to the overall tx effect. With longer follow up, Arm A highlights the clinically meaningful and durable responses of atezo + bev. Coupled with a tolerable safety profile, these data suggest that atezo + bev is a promising first-line tx option for unresectable HCC. (Table Presented) .