A Study of PLM60 in Subjects With Relapsed Small-cell Lung Cancer After Platinum-based First-Line Chemotherapy

Inclusion Criteria: 1. Histologically confirmed diagnosis of SCLC; 2. Must have recurrence or progression after platinum-based first-line chemotherapy or chemoradiation therapy for the treatment of SCLC; 3. ECOG performance status 0\~2; 4. Measurable lesion according to RECIST v1.1; 5. Life expectancy ≥ 12 weeks; 6. Adequate organ function; 7. Signed informed consent from the patient. Exclusion Criteria: 1. Radical surgical treatment for primary small cell lung cancer; 2. Any anti-tumor treatment received within 4 weeks before the first use of the study drug; 3. Untreated or symptomatic central nervous system (CNS) metastases; 4. Uncontrolled pleural effusion, pericardial effusion, or ascites requiring repeated drainage; 5. History of serious systemic diseases; 6. History of serious autoimmune diseases; 7. Those receiving treatment of adriamycin or other anthracyclines previously, with the total cumulative adriamycin (or adriamycin-equivalent) dose of \>360 mg/m2.