1991P Safety and effectiveness of surgery or radiotherapy after PD-L1 Inhibitor (TQB-2450) and chemotherapy induction therapy in patients with limited-stage small cell lung cancer: A phase II trial

PD-1/PD-L1 inhibitor and chemotherapy improved the survival of patients with extensive-stage small-cell lung cancer. Thus, we conducted a non-randomized, single-center, phase II study (LungMate-005; NCT04539977) to explore the safety and effectiveness of surgery or radiotherapy after PD-L1 inhibitor (TQB2450) and chemotherapy induction therapy in treating limited-stage small-cell lung cancer (LS-SCLC). Eligible patients received four 21-day-cycles of neoadjuvant therapy: TQB2450 (1200 mg) and carboplatin (AUC5) on day1, etoposide (100 mg/m2) on day1-3. MDT to discuss surgery or radiotherapy was performed 3-4 weeks after last dose of therapy. Maintenance therapy was 2-cycles TQB2450, carboplatin, and etoposide followed by 1-year TQB2450. The primary outcome was objective response rate (ORR). Secondary outcomes included the incidence of adverse events (AEs), events-free survival (EFS), and major pathological response (MPR). Between December 2020 to January 2023, a total of 40 patients received induction therapy. Among them, 21 and 14 patients received surgery or radiotherapy, respectively. Other 5 patients quitted during induction therapy. Most (95%) patients were at stage III. The incidence of any grade and grade 3-5 AE were 100% and 47.5%, respectively. The highest incidence of TQB2450-specific AEs was rush (12.5%, grade 1-2). Three (7.5%) patients had TRAEs leading to discontinuation. ORR was 92.5% (95%CI: 79.6%-98.4%). In surgery group, 13 (61.9%) patients achieved MPR, including 9 (42.9%) patients with PCR. Seventeen (81.0%) patients achieved pathological downstage. The median followed-up was 14.8 months by April 21, 2023. The median EFS and median OS were not reached in surgery group. The median EFS and OS were 11.6 (95% CI: 8.9-14.3) and 18.6 (95% CI: 13.4-23.8) months in radiotherapy group. 1-year EFS and OS were 82.0% and 100% in surgery group, and 49.2% and 88.9% in radiotherapy group, respectively. Surgery or radiotherapy after PD-L1 inhibitor (TQB-2450) and chemotherapy induction therapy followed by TQB-2450 maintenance therapy in treating LS-SCLC were safe and effective, especially surgery.