Phase 2 dose-ranging study to evaluate the efficacy and safety of liposomal irinotecan (LY01610) as a second-line treatment for patients with relapsed small cell lung cancer

Abstract

This was a multicenter, single-arm dose-ranging phase 2 study aimed to assess the efficacy and safety of LY01610, a liposomal irinotecan, at various doses for patients with relapsed small cell lung cancer (SCLC). This study (NCT04381910) enrolled patients with relapsed SCLC at 10 hospitals across China, who have failed with previous platinum-based treatments. LY01610 was administered at doses of 60mg/m2, 80mg/m2, and 100mg/m2. Primary endpoints were investigator-assessed objective response rate (ORR) and investigator-assessed duration of response (DoR). Secondary endpoints included investigator-assessed disease control rate (DCR), investigator-assessed progression-free survival (PFS), overall survival (OS), and safety. From September 3, 2020 to March 3, 2022, a total of 66 patients were enrolled, with 6, 30, and 30 allocated to the 60mg/m2, 80mg/m2, and 100mg/m2 dose groups, respectively, with 68% (45/66) having a chemotherapy-free interval <90 days. In all 66 patients, the ORR was 32% (21/66, 95% confidence interval [CI], 21-44), with a median DoR of 5.2 months (95% CI, 3.0-8.3). Median PFS and OS were 4.0 (95% CI, 2.9-5.5) and 9.7 (95% CI, 7.2-12.3) months, respectively. The ORR of 60mg/m2, 80mg/m2, and 100mg/m2 dose group were 33% (2/6), 33% (10/30), and 30% (9/30), respectively. The median DoR of 60mg/m2, 80mg/m2, and 100mg/m2 dose group were 4.2 (95% CI, 2.8-not reached), 6.9 (95% CI, 2.5-9.9), and 4.0 (95% CI, 2.7-6.8) months, respectively. The incidence of ≥ grade 3 treatment-related adverse events (TRAEs) in the 60mg/m2, 80mg/m2, and 100mg/m2 dose group were 33% (2/6), 47% (14/30), and 50% (15/30), respectively. Themost common≥grade 3 TRAEs of all 66 patients were neutropenia (27%), leukopenia (24%) and anemia (15%). LY01610 exhibited promising clinical efficacy and manageable safety profiles in patients with relapsed SCLC, the 80mg/m2 dose group had the best benefit-risk ratio. This study was supported by Luye Pharma Group Ltd.