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

Background: 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). Methods: 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 60 mg/m2, 80 mg/m2, and 100 mg/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. Findings: From September 3, 2020 to March 3, 2022, a total of 66 patients were enrolled, with 6, 30, and 30 allocated to the 60 mg/m2, 80 mg/m2, and 100 mg/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 60 mg/m2, 80 mg/m2, and 100 mg/m2 dose group were 33% (2/6), 33% (10/30), and 30% (9/30), respectively. The median DoR of 60 mg/m2, 80 mg/m2, and 100 mg/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 60 mg/m2, 80 mg/m2, and 100 mg/m2 dose group were 33% (2/6), 47% (14/30), and 50% (15/30), respectively. The most common ≥ grade 3 TRAEs of all 66 patients were neutropenia (27%), leukopenia (24%) and anemia (15%). Interpretation: LY01610 exhibited promising clinical efficacy and manageable safety profiles in patients with relapsed SCLC, the 80 mg/m2 dose group had the best benefit-risk ratio. Funding: This study was supported by Luye Pharma Group Ltd.