DAREON®-36: A Study to Test Obrixtamig in Combination With ZL-1310 in People With Advanced Small Cell Lung Cancer or Other Neuroendocrine Cancers

This study is open to adults with advanced small cell lung cancer and other neuroendocrine cancers. The study has 2 parts. The purpose of Part 1 is to find a suitable dose of a combination study treatment, obrixtamig and ZL-1310. The purpose of Part 2 is to see how obrixtamig and ZL-1310 is tolerated when given with another medicine called a checkpoint inhibitor. Another purpose is to check whether the study treatment can stop the cancer from growing and keep it stable. Obrixtamig and ZL-1310 are being developed to help the immune system fight cancer. In Part 1, participants get obrixtamig and ZL-1310. In Part 2, participants get obrixtamig and ZL-1310 with a checkpoint inhibitor. Part 2 is only open to people with advanced small cell lung cancer. All study treatments are given as infusions into a vein. The study does not have a fixed duration. Participants can receive study treatment for up to 2 years if they benefit from treatment and can tolerate it. Participants visit the study site regularly, with some overnight stays required. During this time, doctors regularly check for health problems that could be caused by the study treatment. They also monitor the size of the tumour(s) and take laboratory tests.