Phase II Study of Pirtobrutinib, Rituximab (PR) in Previously Untreated Low and Intermediate Risk MCL (Mantle Cell Lymphoma) Patients

This study is testing a combination of two drugs — pirtobrutinib and rituximab — in people who have been newly diagnosed with mantle cell lymphoma (a type of blood cancer) and have not yet received any treatment. **You may be eligible if...** - You are 18 or older - You have been newly diagnosed with mantle cell lymphoma (confirmed by a biopsy) - Your cancer is considered low or medium risk (based on how fast the cells are dividing and the size of the tumors) - You have not received any prior treatment for mantle cell lymphoma **You may NOT be eligible if...** - Your lymphoma is classified as high-risk (for example, aggressive or fast-growing disease) - You have had a prior stem cell transplant - You are on blood thinners (anticoagulants) in certain situations Talk to your doctor to see if this trial is right for you.