Sacituzumab Tirumotecan Combined With Immunotherapy in Advanced Thyroid Cancer

This study is testing a combination of a targeted antibody-drug conjugate (sacituzumab tirumotecan, which delivers chemotherapy directly to cancer cells) and immunotherapy in people with advanced or metastatic thyroid cancer that has not responded to standard treatments. **You may be eligible if...** - You are 18 or older with confirmed advanced anaplastic, poorly differentiated, or radioactive iodine-resistant differentiated thyroid cancer - Your cancer has progressed on or after standard targeted therapy (if a relevant mutation is present) - You have measurable disease and are in reasonably good physical condition - Your blood counts and organ function meet acceptable thresholds **You may NOT be eligible if...** - You have previously received a drug targeting TROP2 or a topoisomerase I inhibitor antibody-drug conjugate - You have active brain metastases causing symptoms - You have an active autoimmune disease requiring systemic treatment - You have interstitial lung disease - You are pregnant or breastfeeding - You have HIV or active syphilis Talk to your doctor to see if this trial is right for you.