RecruitingPhase 2Drug trialPhase II Study of Pirtobrutinib, Rituximab (PR) in Previously Untreated Low and Intermediate Risk MCL (Mantle Cell Lymphoma) PatientsTo learn if the chemotherapy-free combination of pirtobrutinib (also called LOXO-305) and rituximab can help provide long term remission in low and intermediate risk MCL.