Abstract
BACKGROUND: Esophageal cancer is one of the most common types of cancer in Japan. Herein, we report the efficacy and safety of E7389-LF plus the immune checkpoint inhibitor, nivolumab, from the esophageal cancer cohort of the phase 2 part of Study 120. METHODS: Eligible patients received E7389-LF 2.1 mg/m(2) plus nivolumab 360 mg intravenously Q3W. The primary objective was to evaluate the objective response rate (ORR); other objectives included safety, progression-free survival (PFS), and overall survival (OS). RESULTS: Of the 35 Japanese patients enrolled, 7 (20.0%) had a partial response as their best overall response, and 14 (40.0%) had stable disease. The ORR was 20.0% (95% CI 8.4-36.9). The duration of response was 5.6 months (95% CI 1.7-not estimable [NE]). The median PFS was 2.81 months (95% CI 1.31-4.17). The median OS was not reached (95% CI 6.54 months-NE). The most common treatment-emergent adverse events were neutropenia (65.7%), pyrexia (60.0%), and leukopenia (57.1%). Select plasma endothelial cell markers levels increased from day 1 of cycle 1 and changes were pronounced between days 8-15 of each cycle. CONCLUSIONS: E7389-LF plus nivolumab showed antitumor activity in patients with unresectable and pretreated esophageal cancer and should be evaluated further in a broader population. CLINICAL TRIAL REGISTRATION: NCT04078295.