The purpose of this study is to evaluate the efficacy and safety of Belotecan administered 5 days every 3 weeks in comparison to Topotecan in Patients with relapsed small cell lung cancer.

A Phase Ⅱb, Randomized, Open, Parallel-Group, Multi-Center Trial to Assess the Efficacy and Safety of Belotecan(CamtoBell inj.) or Topotecan in Patients with Relapsed Small Cell Lung Cancer

Inclusion Criteria:

• At least 18 years of age
• Histological or cytological diagnosis of SCLC
• Limited disease (LD) or Extensive disease (ED) at time of study entry
• Recurrent or progressive SCLC ≥ 90 days of duration of response for firstline therapy
• Measurable disease defined by RECIST criteria
• ECOG Performance Status of 0, 1, or 2
• Life expectancy ≥ 3 months
• Adequate bone marrow, Renal, Hepatic reserve:

absolute neutrophil (segmented and bands) count (ANC) ≥ 1500 cells/mm3 platelet count ≥ 100,000 cells/ mm3 hemoglobin ≥ 9 g/dL Total bilirubin ≤ 1.5 mm3 Alanine aminotransferase (ALT) and aspartate aminotransferase(AST) ≤ 2.0 X ULN Alkaline Phosphatase (ALP) ≤ 2.0 X ULN Serum creatinine ≤ 1.5mg/dL or calculated creatinine clearance > 60mL/min

- Signed a written informed consent

Exclusion Criteria:

• Active infection
• Symptomatic brain lesion
• Any other type of cancer during the previous 5 years
• Severe concurrent diseases
• Prior anticancer therapy within 4 weeks before enroll
• Active pregnancy test and Pregnant or nursing women
• Participation in any investigational drug study within 28 days prior to study entry