This study is a prospective, single-arm, exploratory clinical trial designed to evaluate the efficacy and safety of IBI363 in patients with extensive-stage small cell lung cancer (ES-SCLC) who have progressed after at least two prior lines of standard therapy, including PD-1/PD-L1 inhibitor-based immunotherapy. A total of 35 patients were enrolled. The primary endpoint is the objective response rate (ORR), as assessed by investigators according to RECIST 1.1 criteria. Following a screening period of up to 28 days, patients will receive IBI363 treatment until disease progression, onset of intolerable toxicity, withdrawal of informed consent, completion of 24 months of therapy, discontinuation due to other protocol-specified reasons, or early termination of the study.
Age 18 to 75 years (inclusive), male or female.
Histologically confirmed small cell lung cancer (SCLC).
Extensive-stage SCLC refractory to 2 to 3 prior lines of systemic anti-tumor therapy, which must have included PD-1/PD-L1 immunotherapy.
At least one measurable target lesion as per RECIST 1.1 criteria. The target lesion must be measurable (longest diameter ≥10 mm at baseline, or for lymph nodes, short-axis diameter ≥15 mm) and not have been previously irradiated, or have demonstrated clear progression after local therapy. Lesions solely within the brain are not acceptable as target lesions.
Histological diagnosis of combined small cell lung cancer (e.g., mixed SCLC and NSCLC), transformed non-small cell lung cancer (e.g., SCLC transformed from NSCLC), or transformed SCLC (e.g., NSCLC transformed to SCLC).
Known history of hypersensitivity (≥ Grade 3 per CTCAE v5.0) to any antibody-based therapeutic agent, or known hypersensitivity to the active substance or inactive excipients of the investigational product.
Major surgical procedure (excluding needle biopsy) or significant trauma within 4 weeks prior to the first dose of study treatment, or anticipation of the need for elective surgery during the study period.
Systemic corticosteroid therapy (>10 mg/day prednisone or equivalent) within 14 days prior to the first dose of study treatment, with the following exceptions: topical, ocular, intra-articular, intranasal, or inhaled corticosteroids; short-term prophylactic use (e.g., for contrast media allergy); or treatment with other immunosuppressive agents within 4 weeks.