Adebrelimab plus apatinib for maintenance treatment of extensive-stage small cell lung cancer after first-line induction with adebrelimab plus chemotherapy (CLOG2402-ADAPT): A multi-center, single-arm, phase II trial.

271 Background: Immune checkpoint inhibitors (PD-1/PD-L1) combined with chemotherapy have become the standard first-line treatment for ES-SCLC, but long-term benefit remains limited. Anti-angiogenic therapy with immunotherapy has shown promising activity and may offer synergistic antitumor effects. This study reports the preliminary results of the CLOG2402-ADAPT trial evaluating adebrelimab (a PD-L1 inhibitor) plus apatinib (a VEGFR-2 tyrosine kinase inhibitor) as maintenance therapy. Methods: Patients with ES-SCLC who had not progressed after 4–6 cycles of 1L induction therapy with adebrelimab plus platinum–etoposide were eligible to enter the maintenance phase. These patients received maintenance adebrelimab（1200 mg, IV, q3w） plus apatinib (250 mg, po, qd) until progression, toxicity, or withdrawal. The primary endpoint was progression-free survival (PFS), defined as the time from initiation of maintenance therapy to the first documented disease progression. Secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), time to second progression (PFS2). Results: As of February, 2026, 19 patients entered maintenance phase with a median follow-up of 7.4 months (range 3.4–15.6). Median age was 65 years (49–77); Male and female patients accounted for 58% and 42%. 58% had a current or previous smoking history. Liver metastases were present in 16% and brain metastases in 20%. The median duration of induction therapy was 4.0 months (range, 2.3–6.2). Most patients (85%) achieved a partial response to induction therapy. During the maintenance phase, 17 patients underwent at least one tumor response assessment. The ORR was 12%, with a DCR of 71% (comprising 2 PR, 10 SD, and 2 PD). Median PFS was 4.37 months during the maintenance phase, while the the median PFS from the first dose was 8.43 months. OS remain immature. Treatment-related adverse events (TRAEs) occurred in 86.7% of patients, with grade 3 TRAEs in 13.3% (elevated lipase; interstitial pneumonitis). No treatment-related deaths occurred. Conclusions: Adebrelimab plus apatinib showed clinically meaningful antitumor activity and acceptable tolerability as 1L maintenance therapy in patients with ES-SCLC following induction with adebrelimab plus chemotherapy. Clinical trial information: NCT06480864 .