Study Evaluating the Safety and Efficacy of iR2 in Untreated and Unfit Elderly Patients With DLBCL

This open-label, single arm study will evaluate the efficacy and safety of ibrutinib， lenalidomide, rituximab (iR2) in previously untreated and unfit elderly subjects with diffuse large B-cell lymphoma. Subjects will receive 6 cycles of ibrutinib 560mg, day 1-21, orally (PO) , lenalidomide 25mg, day 1-10, rituximab 375mg/m2, intravenously, every 21 days.