The primary objective of the study is to provide expanded access to and characterize the safety profile of tarlatamab in participants with advanced small cell lung cancer (SCLC) after two or more prior lines of treatment (including at least one platinum-based regimen).

EA may still be available in countries outside of the United States.

Inclusion Criteria:

• Age ≥ 18 years
• Histologically or cytologically confirmed SCLC
• Extensive-stage, unable to be encompassed in a tolerable radiation plan
• Progressed or recurred following 1 platinum-based regimen and at least 1 other prior line of therapy
• Eastern Cooperative Oncology Group (ECOG) PS of 0 to 1
• Minimum life expectancy of 12 weeks

Exclusion Criteria:

• Any previous diagnosis of transformed non-small cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) activating mutation positive NSCLC that has transformed to SCLC, or mixed SCLC NSCLC histology
• Symptomatic central nervous system (CNS) metastases
• Active hepatitis B or hepatitis C virus infection
• Eligible for participation in any Amgen-sponsored ongoing clinical study of the investigational product
• Currently or previously enrolled in a prior tarlatamab study
• Female participants and/or male participants with female partners who are pregnant, breastfeeding, planning to become pregnant or donate eggs while on study through 60 days after the last dose of tarlatamab
• Male and female participants unwilling to practice abstinence and/or use protocol specified method of contraception