Polatuzumab Vedotin (Pola) Plus Rituximab (R) in Patients With Post-transplant Lymphoproliferative Disorder (PTLD)

This study is testing a combination of two drugs — polatuzumab vedotin and rituximab — to treat a rare type of lymphoma called post-transplant lymphoproliferative disorder (PTLD), which can develop in people who have had an organ or bone marrow transplant and are on immune-suppressing medications. **You may be eligible if...** - You are 18 or older - You developed a type of lymphoma (PTLD) after receiving a solid organ transplant or bone marrow/stem cell transplant - Your lymphoma is confirmed to be CD20-positive (a protein marker on the cancer cells) and has not been treated before - Your blood counts and organ function are within acceptable ranges **You may NOT be eligible if...** - You have already received treatment for this lymphoma - Your liver or kidney function is significantly impaired - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.