Phase I study of the VEGF/Ang-2 inhibitor BI 836880 alone or combined with the anti-programmed cell death protein-1 antibody ezabenlimab in Japanese patients with advanced solid tumors

Purpose This two-part, open-label, non-randomized dose-escalation study aimed to define the maximum tolerated dose (MTD) of BI 836880 (humanized bispecific nanobody® targeting vascular endothelial growth factor and angiopoietin-2) as monotherapy and in combination with ezabenlimab (programmed death protein-1 inhibitor) in Japanese patients with advanced and/or metastatic solid tumors. Methods In part 1, patients received an intravenous infusion of BI 836880 at 360 or 720 mg every 3 weeks (Q3W). In part 2, patients received BI 836880 at doses of 120, 360, or 720 mg in combination with ezabenlimab 240 mg Q3W. The primary endpoints were the MTD and the recommended phase II dose (RP2D) of BI 836880 as monotherapy and in combination with ezabenlimab, based on dose-limiting toxicities (DLTs) during the first cycle. Results Twenty-one patients were treated; nine in part 1 and 12 in part 2. No DLTs were reported in either part and the MTD was not reached. The RP2Ds were BI 836880 720 mg Q3W as monotherapy and BI 836880 720 mg plus ezabenlimab 240 mg Q3W. The most common adverse events were hypertension and proteinuria (33.3%) with BI 836880 monotherapy and diarrhea (41.7%) with the combination. Four patients (44.4%) in part 1 had stable disease as best overall tumor response. In part 2, two patients (16.7%) had confirmed partial responses and five had stable disease (41.7%). Conclusion MTD was not reached. BI 836880 alone and in combination with ezabenlimab had a manageable safety profile with preliminary clinical activity in Japanese patients with advanced solid tumors. Trial registration and date NCT03972150, registered on June 3, 2019.