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

• Sacituzumab Govitecan (SG) (Drug), also known as Trodelvy®, GS-0132, IMMU 132: Administered intravenously
• Topotecan (Drug): Administered intravenously
• Amrubicin (Japan only) (Drug): Administered intravenously
• Lurbinectedin (regions/countries where approved and available) (Drug): Administered intravenously

Primary outcomes

• Overall Survival (OS) [Up to 4.5 years]: OS is defined as length of time from randomization until the date of death from any cause.

Secondary outcomes

• Progression-free Survival (PFS) [Up to 4.5 years]: PFS is defined as the time from date of randomization until disease progression as assessed by investigator according to RECIST v1.1 or death from any cause, whichever comes first.
• Objective Response Rate (ORR) [Up to 4.5 years]: ORR is defined as the percentage of participants who have achieved a CR or PR as assessed by investigator according to RECIST v1.1.
• Duration of Response (DOR) [Up to 4.5 years]: DOR is defined as is measured from the time of first response (CR or PR) as assessed by investigator according to RECIST v1.1, until the date of first documented disease progression or death, whichever comes first
• Time to First Deterioration in Shortness of Breath Domain [Up to 4.5 years]: Time to first deterioration is defined as the time from the date of randomization to the first time a participant experienced change from baseline equal to or greater than the prespecified threshold value for deterioration or death.
• Time to First Deterioration in Physical Functioning Domain [Up to 4.5 years]: Time to first deterioration is defined as the time from the date of randomization to the first time a participant experienced change from baseline equal to or greater than the prespecified threshold value for deterioration or death.
• Percentage of Participants Experiencing Treatment-emergent Adverse Events (TEAEs) [First dose date up to 4.5 years]: TEAE is defined as any AEs occurred during the treatment-emergent period. The treatment-emergent period is defined as the time period from the first dose of study treatment to the earlier of 30 days following the last dose of study treatment or the initiation of subsequent anticancer therapy.
• Percentage of Participants Experiencing Clinical Laboratory abnormalities [First dose date up to 4.5 years]: Laboratory abnormality is defined as any value that increases at least 1 toxicity grade from baseline.

Sex: All, ages: 18 Years to any

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 of platinum-containing chemotherapy (defined as at least 2 cycles of treatment) with or without therapy directed against programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1; PD-1 and PD-L1 are hereafter referred to as PD-(L)1) for ES-SCLC.
* Individuals treated with a platinum-based therapy for prior limited stage small cell lung cancer will be counted as 1 prior line of platinum-containing chemotherapy if the disease has progressed within 30 to 180 days from last dose of platinum treatment.
* If the investigator believes a participant may benefit from platinum rechallenge it can be considered per investigator discretion and local SOC; however, participants with platinum rechallenge may not participate in the study.
* If the investigator believes a participant may benefit from tarlatamab treatment, it can be considered per investigator discretion and local SOC and such participants may 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-line platinum-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, exatecan derivatives, and similar agents targeting topoisomerase I. Received lurbinectedin after progression on or after platinum-based chemotherapy.
* Have carcinomatous meningitis and/or non-carcinomatous meningitis central nervous system (CNS) metastasis apart from the following noted exceptions. Participants with previously treated brain metastases may participate provided they have stable CNS disease (ie, without evidence of progression) for at least 4 weeks (independent from completion of definitive treatment) prior to randomization and all neurologic symptoms have returned to baseline, have no evidence of new or enlarging brain metastases, and are taking ≤ 10 mg/day of prednisone or its equivalent. Participants with untreated, clinically stable brain metastases will be allowed if they are asymptomatic and the investigator determines there is no immediate CNS-specific treatment required, there is no surrounding edema, and the brain metastases are of 5 mm or less in size and 3 or fewer lesions.

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

119 more sites not listed.

• Gilead Study Director, Study director, Gilead Sciences