Study of Sacituzumab Govitecan Versus Standard of Care in Participants With Previously Treated Extensive Stage Small Cell Lung Cancer

Key Inclusion Criteria:

• Histologically confirmed diagnosis of SCLC.

• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.

• Measurable disease by computed tomography (CT) or magnetic resonance imaging (MRI)as assessed by investigator per RECIST v1.1 criteria.

• Documentation of radiological disease progression after 1 prior line ofplatinum-containing chemotherapy (defined as at least 2 cycles of treatment) with orwithout therapy directed against programmed cell death protein 1 (PD-1) orprogrammed cell death ligand 1 (PD-L1; PD-1 and PD-L1 are hereafter referred to asPD-(L)1) for ES-SCLC.

• Individuals treated with a platinum-based therapy for prior limited stage small celllung cancer will be counted as 1 prior line of platinum-containing chemotherapy ifthe disease has progressed within 30 to 180 days from last dose of platinumtreatment.

• If the investigator believes a participant may benefit from platinum rechallenge itcan be considered per investigator discretion and local SOC; however, participantswith platinum rechallenge may not participate in the study.

• If the investigator believes a participant may benefit from tarlatamab treatment, itcan be considered per investigator discretion and local SOC and such participantsmay participate in the study following tarlatamab treatment.

Note: at least 85% of participants included in the study must be pretreated with anti-PD-[L]1 therapy.

Refer to protocol for country-specific requirements for participants in China.

Key Exclusion Criteria:

• Chemotherapy-free interval (CTFI) time from the last dose of first-lineplatinum-containing chemotherapy to the occurrence of progressive disease) < 30 days (independent of the immunotherapy maintenance).

• Received any prior treatment with irinotecan, topotecan, SG, SN-38, exatecanderivatives, and similar agents targeting topoisomerase I. Received lurbinectedinafter progression on or after platinum-based chemotherapy.

• Have carcinomatous meningitis and/or non-carcinomatous meningitis central nervoussystem (CNS) metastasis apart from the following noted exceptions. Participants withpreviously treated brain metastases may participate provided they have stable CNSdisease (ie, without evidence of progression) for at least 4 weeks (independent fromcompletion of definitive treatment) prior to randomization and all neurologicsymptoms have returned to baseline, have no evidence of new or enlarging brainmetastases, and are taking ≤ 10 mg/day of prednisone or its equivalent. Participantswith untreated, clinically stable brain metastases will be allowed if they areasymptomatic and the investigator determines there is no immediate CNS-specifictreatment required, there is no surrounding edema, and the brain metastases are of 5mm or less in size and 3 or fewer lesions.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.