DESTINY-PANTUMOUR04

This study (DESTINY-PANTUMOUR04) is testing trastuzumab deruxtecan (T-DXd), an antibody-drug combination, for a variety of HER2-positive solid tumors (cancers that overexpress a protein called HER2) that have progressed after prior treatment and have no good remaining options. **You may be eligible if...** - You are 18 years or older - You have an advanced, unresectable, or metastatic solid tumor that tests HER2-positive (IHC 3+) on a biopsy - You have already received at least one prior systemic treatment for your cancer - There are no satisfactory standard treatment options remaining **You may NOT be eligible if...** - Your tumor does not test as HER2-positive (IHC 3+) - You have not received prior treatment for your advanced cancer - You have brain metastases that are not stable - You have serious lung, heart, or other organ problems - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.