SKB500 Combinations in Patients With Small Cell Lung Cancer

Inclusion criteria

• Male or female participants between 18 and 75 years old.
• Histologically or cytologically confirmed Extensive-stage small cell lung cancer (ES-SCLC):
• Cohort 1: participant has received or not received prior systemic treatment, with no more than 1 prior systemic therapy in the extensive stage.
• Cohort 2\~3: participant has received no prior systemic treatment.
• Agree to provide fresh or archival tumor tissue for biomarker analysis.
• Has at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Life expectancy \>= 12 weeks.
• Has adequate organ and bone marrow functions.
• Has recovered to grade ≤ 1 of prior anti-cancer treatment toxicities.
• Effective contraceptive methods should be used during the study and for 6 months after the end of treatment.
• Voluntarily join this study, sign the informed consent form, and can comply with the protocol-specified visits and procedures.

Exclusion criteria

• The pathology suggests the presence of both non-small cell carcinoma and small cell carcinoma components.
• Has previously received medications with the same target or the same toxins.
• Presence of spinal cord compression or clinically active central nervous system metastases.
• Presence of clinical symptoms caused by tumor invasion or compression of important organs and blood vessels.
• Severe infection within 4 weeks or active infection requiring systemic anti-infective treatment within 2 weeks prior to the first dose.
• With peripheral neuropathy of grade ≥ 2.
• History of any serious, life threatening, or permanently discontinuing adverse events mediated by immunotherapy, including infusion reactions.
• Presence of uncontrolled concurrent diseases, including but not limited to decompensated liver cirrhosis, nephrotic syndrome, uncontrolled metabolic disorders, Severe active peptic ulcer, gastrointestinal bleeding, gastrointestinal perforation, intestinal obstruction, etc.
• Serious or uncontrolled heart disease or clinical symptoms requiring treatment.
• History of interstitial lung disease (ILD) /noninfectious pneumonitis that require steroid treatment, or currently has ILD/noninfectious pneumonitis.
• Clinical severe lung damage caused by concurrent lung disease.
• Uncontrolled hypertension, diabetes, or repeated drainage of pleural effusion/pericardial effusion/ abdominal effusion.
• Pregnant or lactating women.
• Rapid disease deterioration in the screening process.