Bintrafusp alfa and chemotherapy as first-line treatment in biliary tract cancer: A randomized phase 2/3 trial.

Abstract

We compared the safety and efficacy of bintrafusp alfa (BA) in combination with gemcitabine+cisplatin (GemCis), to those of GemCis alone, in patients with biliary tract cancer (BTC). This randomized, double-blind, placebo-controlled, adaptive design phase 2/3 trial (NCT04066491) included treatment-naïve adults with locally advanced/metastatic BTC. Patients (N=297) were randomized to receive an intravenous infusion of BA (2400mg once/3wk) plus GemCis (gemcitabine 1000mg/m2+cisplatin 25mg/m2 on days 1 and 8/3wk; 8 cycles) (BA group, n=148) or placebo+GemCis (placebo group, n=149). The primary endpoint was overall survival (OS). For adaptation analysis (phase 2-phase 3; data cut-off: May 20, 2021), efficacy was assessed in the first 150 patients who were antibiotic-naïve, when 80 progression-free survival events had occurred and ≥19 weeks of follow-up had been completed (BA, n=73; placebo, n=77). Median OS (95% CI) for the BA (11.5mo [9.3-not estimable, NE]) and placebo (11.5mo [10.0-NE]) groups was comparable (hazard ratio 1.23 [95% CI 0.66-2.28]; p=0.7394); OS data maturity was 27.2% (41 events/151 patients). The most common grade ≥3 treatment-related adverse event was anemia (BA, 26.0%; placebo, 22.8%). Bleeding adverse events were reported more frequently in the BA group (28.8%) versus the placebo group (7.4%). Deaths within 60 days of the first dose were reported in 7.5% and 1.3% of patients in the BA and placebo groups, respectively. BA+GemCis did not provide a clinically meaningful benefit compared to GemCis alone as first-line treatment for BTC and the study was discontinued early (terminated: August 20, 2021).