A Study of ZL-1310 Versus Investigator's Choice of Therapy in Participants With Relapsed Small Cell Lung Cancer (DLLEVATE)

Inclusion Criteria:

• Age >/= 18 years, or considered an adult by local regulations, at the time ofconsent

• Signed informed consent

• Histologically or cytologically confirmed SCLC. Received 1L platinum-based systemictherapy and had documented disease progression during or after the most recentsystemic therapy. Or received 2L tarlatamab is allowed.

• Measurable disease according to RECIST v1.1 as assessed by the investigator.

• Participants with a history of treated and stable or untreated and asymptomatic CNSmetastases based on criteria per protocol.

• Adequate organ and marrow function

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

• Life expectancy of at least 3 months

• Participants must be willing to undergo a tumor biopsy or provide archived tumortissue sample at Screening

• Participants must be willing and able to comply with protocol for the duration ofthe study

Exclusion Criteria:

• Received more than one line of systemic therapy for Extensive-Stage SCLC.

• Received any prior ADC with topoisomerase 1 inhibitor payload

• Participants with another known malignancy with exceptions defined in the protocol.

• History or suspected ILD/pneumonitis based on criteria per protocol

• Clinically severe pulmonary compromise resulting from intercurrent pulmonaryillnesses.

• Receipt of anti-cancer treatment known to treat cancers within 3 weeks before thefirst dose of study treatment.

• Prior radiotherapy before study treatment based on criteria per protocol

• Unresolved toxicity of Grade >/= 2 from previous anti-cancer treatment, except foralopecia and skin pigmentation.

• Known infection or active infection defined in the protocol.

• Clinically significant active cardiovascular disease or history of arterialthromboembolic event within 6 months prior to the first dose of study treatmentbased on criteria per protocol.