STAR0602 With Nivolumab in Non Small Cell Lung Cancer and in Metastatic Castrate-Resistant Prostate Cancer, and STAR0602 Alone in Thymic Carcinoma

Background: Immunotherapy is a type of treatment that works by making the body s own immune system stronger. These treatments are used for cancers such as non small cell lung cancer (NSCLC); thymic carcinoma (TC); or metastatic castrate-resistant prostate cancer (mCRPC). But these cancers may still come back after treatment. Objective: To test a new immunotherapy drug (STAR0602), alone or combined with an approved drug (nivolumab), in people with NSCLC, mCRPC, or TC. Eligibility: People aged 18 years or older with NSCLC, mCRPC, or TC that did not respond to treatment or returned after treatment. Design: Participants will be screened. They will have blood and urine tests. They will have imaging scans and a test of their heart function. STAR0602 and nivolumab are given through a needle inserted into a vein (infusion). Participants will be treated in 28-day cycles. They will receive infusions of 1 or both drugs on the first and 15th day of each cycle. They will remain in the hospital for up to 5 days after their first 2 infusions of STAR0602. Imaging scans, blood tests, and other tests may be repeated during study visits. Participants may opt to have tissue samples (biopsies) taken from their tumors. Some blood and tissue samples may be used for genetic tests. Participants may continue getting STAR0602 for up to 2 years and nivolumab for up to 6 months. Participants will have an end-of-study visit within 1 month, and follow-up phone calls 1 month and 3 months, after they stop the study drug. Long-term follow-up calls and visits will continue every 3 to 6 months for up to 5 years.