A Study of BL-B01D1, SI-B003 and BL-B01D1+SI-B003 in Patients With Extensive Stage Small Cell Lung Cancer

Excluded: EGFR monoclonal antibody therapy

Previous treatment with EGFR and HER3 monoclonal antibodies

Excluded: ERBB3 monoclonal antibody therapy

Previous treatment with EGFR and HER3 monoclonal antibodies

Must have received: systemic antitumor therapy — Cohort_A: failed or intolerant to 3 or more lines

Cohort_A cohort of patients with extensive-stage small cell lung cancer who had failed or were intolerant to 3 or more lines of systemic antitumor therapy

Must have received: standard therapy — Cohort_B Stage I: previous failure or intolerance

Cohort_B Stage I subjects with previous failure or intolerance to standard therapy for extensive-stage small cell lung cancer

Cannot have received: EGFR monoclonal antibody

Previous treatment with EGFR and HER3 monoclonal antibodies

Cannot have received: HER3 monoclonal antibody

Previous treatment with EGFR and HER3 monoclonal antibodies

Cannot have received: antineoplastic therapy

Exception: within 4 weeks or 5 half-life cycles (whichever is shorter) before the first dose; oral fluorouracil drugs such as S-1, capecitabine, or palliative radiotherapy within 2 weeks before the first dose

Antineoplastic therapy, including chemotherapy, biologic therapy, immunotherapy, definitive radiotherapy, major surgery (investigator-defined), or targeted therapy (including small-molecule tyrosine kinase inhibitors), has been administered within 4 weeks or 5 half-life cycles (whichever is shorter) before the first dose; Oral fluorouracil drugs such as S-1, capecitabine, or palliative radiotherapy within 2 weeks before the first dose

Cannot have received: systemic therapy

Cohort_B Stage II patients who had received any previous systemic therapy for extensive-stage SCLC were not eligible for the study

Cannot have received: immunotherapy

Exception: Cohort_B only; history of immunotherapy and grade ≥3 irAE or grade ≥2 immune-related myocarditis

Cohort_B with a history of immunotherapy and grade ≥3 irAE or grade ≥2 immune-related myocarditis, excluded

Cannot have received: immunomodulatory drugs (thymosin, interleukin-2, interferon)

Exception: Cohort_B only; within 14 days before the first dose

Cohort_B with history of use of immunomodulatory drugs (including but not limited to thymosin, interleukin-2, interferon, etc.) within 14 days before the first dose of study drug was excluded