First-in-Human Trial of DS-2243a in Participants With Advanced Solid Tumors

This is a first-in-human study testing DS-2243a, a new experimental treatment, in patients with certain advanced solid tumors that have not responded to standard therapies. The drug targets cancer cells that carry a specific protein identified through a genetic marker. **You may be eligible if...** - You are 18 years or older - You have advanced (metastatic or unresectable) synovial sarcoma, myxoid/round cell liposarcoma, non-small cell lung cancer, or urothelial (bladder/urinary tract) cancer - Your cancer has not responded to or is no longer benefiting from standard treatment - You carry the HLA-A*02 genetic marker (a common immune system marker detectable by a blood test) - You have measurable disease on a scan - You are in good physical health (ECOG score 0 or 1) **You may NOT be eligible if...** - You do not carry the required HLA-A*02 genetic marker - You have poor organ function (low blood counts, kidney or liver problems) - You are unable to provide a tumor tissue sample - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.