A PHASE 1B/2, MULTICENTER, OPEN-LABEL STUDY OF IFINATAMAB DERUXTECAN (I-DXd), A B7-H3 ANTIBODY-DRUG CONJUGATE (ADC), IN COMBINATION WITH ATEZOLIZUMAB WITH OR WITHOUT CARBOPLATIN AS FIRST-LINE INDUCTION OR MAINTENANCE, IN SUBJECTS WITH EXTENSIVE-STAGE

The purpose of this study is to learn more about an investigational drug, which is not approved by the United States Food and Drug Administration, called ifinatamab deruxtecan (I-DXd). It is being studied to see if it is safe and if your disease, extensive- stage small cell lung cancer (ES-SCLC), or other medical condition improves while taking it alongside other drugs, Atezolizumab, Carboplatin, and Etoposide. I-DXd is a type of drug called an antibody-drug conjugate, which is made up of 2 parts: an antibody and an anticancer drug. The antibody part binds to a protein commonly found on tumor cells called humanized anti B7 homologue 3 (B7-H3), while the drug is released to attack cancer cells. By using an antibody, the drug may be able to reach the tumor directly while sparing healthy cells. We hope this will decrease the side effects caused by chemotherapy and make sure that tumor cells are effectively killed.

Are you Eligible? (Inclusion Criteria)

• 18 years or older at the time the ICF is signed 2. Has histologically or cytologically documented ES-SCLC 3. IS willing and able to comply with scheduled visits, drug administration plan, laboratory tests, other study procedures, and study restrictions