50 (15%) pts received maintenance rituximab (MR) with fewer cases of high grade B-cell lymphoma with MYC, BCL2 and/or BCL6 rearrangements (HGBL-DH) compared to the non-MR cohort (0% v 10%)…In patients who achieved PR or greater following FLT, MR was associated with improved PFS on MVA (HR 0.6, 95% CI 0.3-0.9, P=0.04) without an OS benefit (P=0.2).