Clinical Summary:

• Design/Population: A phase 2 multicenter, single-arm trial evaluated ivonescimab plus liposomal irinotecan in patients with small cell lung cancer who progressed after platinum-based chemoimmunotherapy.
• Key Outcomes: The regimen demonstrated encouraging antitumor activity, with a high 6-month progression-free survival rate, objective response rate, and disease control rate. Benefit appeared greater in patients with a longer chemotherapy-free interval. 
• Clinical Relevance: Ivonescimab plus liposomal irinotecan may provide a promising second-line treatment option, supporting further evaluation in randomized trials.

According to results from a phase 2 study, ivonescimab plus liposomal irinotecan showed promising efficacy and safety among patients with small cell lung cancer (SCLC) who experienced disease progression after treatment with platinum-based chemoimmunotherapy. 

These results were presented by Yun Fan, MD, Zhejiang Cancer Hospital, Hangzhou, China, at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois. 

In this multicenter, single-arm trial, 60 patients received 20 mg/kg ivonescimab intravenously once every 3 weeks plus 56.5 mg/m² liposomal irinotecan intravenously once every 2 weeks until disease progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). Key secondary end points included overall survival (OS), objective response rate (ORR), disease control rate, and safety. 

At a median follow-up of 7.3 months, 63.3% of patients had a chemotherapy-free interval >90 days. Median PFS was 9.8 months, with a 6-month PFS rate of 72%. Median PFS was 11.9 months in patients with a CFI ≥90 days and 7 months in patients with a CFI <90 days. Median OS had not yet been reached. Confirmed ORR was 61.7%, with all responses classified as partial. The disease control rate was 91.7%. 

Grade ≥3 treatment-related adverse events were reported in 26.7% of patients, and most frequently included neutrophil count decrease (8.3%), white blood cell count decrease (8.3%), fatigue (6.7%), and diarrhea (3.3%). Treatment-related adverse events led to interruptions in 31.7% of patients and chemotherapy dose reductions in 25% of patients. Adverse events did not lead to treatment discontinuations. Immune-related adverse events were reported in 33.3% of patients, 8.3% of which were grade 3. No grade ≥ 4 immune-related adverse were reported and there were no treatment-related deaths. 

“Ivonescimab combined with liposomal irinotecan demonstrated encouraging antitumor activity with a manageable safety profile as a second-line treatment for SCLC pts after platinum-based chemoimmunotherapy,” concluded Dr Fan. “These results support further investigation in randomized controlled trials.”

Source:

Fan Y, Chen K, Li H, et al. Efficacy and safety of ivonescimab combined with liposomal irinotecan in patients with small-cell lung cancer (SCLC) progressing after first-line chemoimmunotherapy: A multicenter, phase 2 study. Presented at the ASCO Annual Meeting. May 29 - June 2, 2026. Chicago, Illinois. Abstract 8007.