Study of Orally Administered MOMA-341 in Participants With Advanced or Metastatic Solid Tumors

This study is testing a new oral drug called MOMA-341 in people with advanced or metastatic solid tumors that have a specific DNA repair defect (called MSI-H or dMMR), which affects how cancer cells fix their DNA and makes them respond differently to treatment. **You may be eligible if...** - You are 18 or older with advanced or metastatic solid tumors confirmed by biopsy - Your tumor has been tested and found to have MSI-H (microsatellite instability-high) or dMMR (mismatch repair deficient) status - Your cancer has progressed after receiving an anti-PD-(L)1 immunotherapy (checkpoint inhibitor), unless that treatment was not available or not appropriate for you - You have acceptable organ function and are physically well (ECOG score 0–2) **You may NOT be eligible if...** - Your cancer has not been tested for MSI/MMR status, or results are negative - You have active brain metastases - You are pregnant or breastfeeding - You have uncontrolled infections or serious medical conditions Talk to your doctor to see if this trial is right for you.