Ezabenlimab (BI 754091), an anti-PD-1 antibody, in patients with advanced solid tumours

Ezabenlimab (BI 754091) is a humanised monoclonal antibody targeting programmed cell death protein-1. We report results from open-label, dose-escalation/expansion, Phase I trials that evaluated the safety, maximum tolerated dose (MTD), pharmacokinetics and antitumour activity of ezabenlimab at the recommended Phase II dose in patients with selected advanced solid tumours. Study 1381.1 (NCT02952248) was conducted in Canada, the United Kingdom and the United States. Study 1381.4 (NCT03433898) was conducted in Japan. Study 1381.3 (NCT03780725) was conducted in the Netherlands. The primary endpoints were: number of patients experiencing dose-limiting toxicities (DLTs) in the first cycle (dose escalation parts), number of patients with DLTs during the entire treatment period and objective response (dose expansion part of Study 1381.1). Overall, 117 patients received ezabenlimab intravenously every 3 weeks (80 mg, n = 3; 240 mg, n = 111; 400 mg, n = 3). No DLTs were observed and the MTD was not reached. Fifty-eight patients (52.3