The purpose of this study is to evaluate the safety and efficacy of Zepzelca™ inj. in real-world practice and to investigate important identified risks and gaps in information related to risk management plans.

Inclusion Criteria:

• Patients who voluntarily provide written consent for personal information collection and utilization after receiving an explanation about the objective and methods of the study
• Patients who have received or are scheduled to receive Zepzelca™ inj., according to domestic approval indications
• Patients with metastatic SCLC who have failed first-line platinum-based chemotherapy

Exclusion Criteria:

• Patients with no prior history of platinum-based anticancer chemotherapy for cancer treatment
• Patients with a history of hypersensitivity reactions to this drug or its components
• Pregnant, potentially pregnant, or lactating women
• Patients currently participating in another clinical trial (drug or medical device) or planning to participate in another clinical trial during the study period (except for non-interventional clinical studies or cases where the clinical trial drug administration has ended and only follow-up is remaining)
• Patients who are judged by the principle Investigator or sub-Investigator to be ineligible to participate in the study.

Patients With Metastatic SCLC who have failed first-line platinum-based chemotherapy