Patients were treated with 3-6 cycles of chemotherapy +/- rituximab, with type and duration at the discretion of the individual clinician. Evaluation for response was performed 1 month after completing chemotherapy, and included computed tomography (CT) scan, bone marrow biopsy, endoscopy, and colonoscopy. Minimal residual disease (MRD) was assessed qualitatively on bone marrow specimens using polymerase chain reaction (PCR) with standardized primers for evaluation for B-cell receptor gene rearrangement. Responses were defined according to revised Cheson criteria. Patients with successful lymph node harvest who had obtained complete or partial response could proceed to bystander vaccination.
The GM.CD40L bystander vaccine administered intradermally into the bilateral axillary and inguinal nodal basins via eight separate injections (0.125 ml / injection). Low dose IL-2 (0.5 x 10\^6 units) was given subcutaneously twice daily for 14 days following vaccination. Patients were restaged with CT and/or CT/PET and bone marrow biopsy every 6 months, beginning from the last date of chemotherapy. Follow-up bone marrow biopsy evaluation included an assessment for MRD as described above. Patients without disease progression or toxicity attributable to the vaccine were eligible for 4 monthly booster vaccines at 12 months and 24 months.
