Safety and Efficacy of Radiotherapy Combined With Sintilimab in Advanced NSCLC Patients Who Progressed on First or Second Line Therapy: A Prospective, Multiple Center, and Single‐Arm Study

BACKGROUND: This study explored the safety and efficacy of combining radiotherapy with sintilimab in non-small cell lung cancer (NSCLC) patients who have progressed after first or second-line therapy. METHODS: In this multicenter, single-arm trial, patients with NSCLC who had progressed after first or second-line therapy were enrolled. Participants received hypofractionated stereotactic body radiotherapy (SBRT) (requiring a single-site biological dose of more than 30 Gy or planned to reach 30 Gy) followed by sintilimab every 3 weeks until disease progression or unacceptable toxicity occurred. RESULTS: From March 1, 2019, to July 27, 2023, 14 patients were enrolled across two centers. The cohort included 64.3% males and 35.7% females, with a median age of 67 years (range 57-73 years). All participants completed radiation therapy and received at least one cycle of sintilimab. The overall response rate (ORR) was 21.4% (3/14) and the disease control rate (DCR) was 71.4% (10/14). The absent radiation response (ARR) was 14.3% (2/14). The median PFS was 4.17 months (95% CI: 1.15-8.69 months), with a 6-month PFS rate of 42.9%. The median OS was 16.17 months (95% CI: 11.69-20.64 months). Overall, 10 patients (71.4%) experienced at least one treatment-emergent adverse event (TEAE). Grade 3 adverse events included one case each of immune-related myocarditis, thrombocytopenia, and checkpoint inhibitor pneumonitis (CIP). Four patients (28.6%) had immune-related adverse events (irAEs) including skin rash and pruritus (2/14, grade 1), immune-related myocarditis (1/14, grade 3), and CIP (1/14, grade 3). CONCLUSIONS: Radiotherapy combined with sintilimab for NSCLC patients who progressed after first-or second-line therapy showed promising efficacy outcomes.