Costimulated tumor-infiltrating lymphocytes are a feasible and safe alternative donor cell therapy for relapse after allogeneic stem cell transplantation

Donor lymphocyte infusion (DLI), a standard relapse treatment after allogeneic stem cell transplantation (AlloSCT), has limited efficacy and often triggers GVHD. We hypothesized that after AlloSCT tumor-infiltrating donor lymphocytes could be costimulated ex vivo to preferentially activate/expand antitumor effectors. We tested the feasibility and safety of costimulated, tumor-derived donor lymphocyte (TDL) infusion in a phase 1 trial. Tumor was resected from 8 patients with B-cell malignancy progression post-AlloSCT; tumor cell suspensions were costimulated with anti-CD3/anti-CD28 Ab-coated magnetic beads and cultured to generate TDL products for each patient. Costimulation yielded increased proportions of T-bet+FoxP3− type 1 effector donor T cells. A median of 2.04 × 107 TDL/kg was infused; TDLs were well tolerated, notably without GVHD. Two transient positron emission tomography (PET) responses and 2 mixed responses were observed in these refractory tumors. TDL are a feasible, tolerable, and novel donor cell therapy alternative for relapse after AlloSCT. This trial is registered at clinicaltrials.gov as no. NCT00445666.