Paclitaxel Polymeric Micelles Plus Ivonescimab in Recurrent or Refractory SCLC

This multicenter, open-label, single-arm phase II investigator-initiated study evaluates the efficacy and safety of ivonescimab combined with paclitaxel polymeric micelles in adults with recurrent or refractory small cell lung cancer after failure of platinum-based chemotherapy and anti-PD-1/PD-L1 therapy. Participants will receive ivonescimab 20 mg/kg intravenously on Day 1 every 3 weeks, followed at least 30 minutes later by paclitaxel polymeric micelles 230 mg/m² intravenously over at least 3 hours on Day 1 every 3 weeks. Paclitaxel polymeric micelles will be administered for up to 4 cycles. Ivonescimab may continue for up to 2 years or until disease progression, initiation of new antitumor therapy, unacceptable toxicity, withdrawal of consent, death, or another protocol-defined reason for discontinuation. Tumor response will be assessed by investigators using RECIST v1.1 every 6 weeks during the first 12 months and every 9 weeks thereafter. The primary endpoint is objective response rate. Secondary endpoints include disease control rate, clinical benefit rate, duration of response, progression-free survival, overall survival, and safety assessed using NCI CTCAE version 5.0.