Phase I study of liposomal irinotecan (LY01610) in patients with advanced esophageal squamous cell carcinoma.

Abstract

e16097 Background: This phase I trial was performed to determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), preliminary efficacy, and pharmacokinetics (PK) of LY01610, a novel liposome-encapsulated irinotecan, in patients with advanced esophageal squamous cell carcinoma (ESCC). Methods: This trial was conducted in two stages. In the dose-escalation stage, patients with advanced ESCC refractory or intolerant to previous chemotherapy received escalating doses of LY01610. A recommended dose based on patient tolerance was then expanded in the second stage. LY01610 was administered intravenously every 2 weeks, except that the first cycle in dose-escalation was three weeks to allow observation of DLTs. Results: Twenty-four patients were enrolled across four dose levels (30, 60, 90 and 120 mg/m2). The DLTs included vomiting and febrile neutropenia, and the MTD was 90 mg/m2. The most common grade 3/4 adverse events were leukopenia in six patients (25.0 %), anemia in six patients (25.0 %) and neutropenia in five patients (20.8 %). One patient achieved complete response, and four had partial response, including one patient receiving LY01610 at the starting dose of 30 mg/m2. Compared with conventional irinotecan, the PK profile of LY01610 was characterized by increased and prolonged exposure of total irinotecan and the active metabolite SN-38 in plasma. Conclusions: LY01610 demonstrated manageable toxicity and promising antitumor activity in patients with advanced ESCC. Future clinical development of LY01610 as single agent or in combination with other anti-cancer agents in treating ESCC patients is warranted. Clinical trial information: NCT04088604.