Donor lymphocyte infusions for relapsed multiple myeloma after allogeneic stem-cell transplantation: Predictive factors for response and long-term outcome

Purpose: To determine the efficacy, toxicity, and long-term outcome and pro gnostic factors of donor lymphocyte infusions (DLI) in patients with relaps ed multiple myeloma (MM) after allogeneic stem-cell transplantation (AlloSC T). Materials and Methods: Twenty-seven patients received 52 DLI courses at a m edian of 30 months after the previous AlloSCT, Reinduction therapy was admi nistered to 13 patients before DLI, Results: Reinduction therapy wets successful in eight of 13 patients. Fourt een patients (52%) responded to DLI, including six patients (22%) who achie ved a complete remission (CR), Five patients responded after T-cell dose es calation in subsequent DLIs. Four patients experienced relapse or disease p rogression (three from partial response and one from CR). Five patients rem ain in remission more than 30 months after DLI, Major toxicity was acute an d chronic graft-versus-host disease (GVHD), which was present in 55% and 26 % of patients, respectively. Two patients died from bone marrow aplasia. Me dian overall survival of all patients was 18 months. Overall survival was 1 1 months for DLI-resistant patients and has not been reached for the respon ding patients. In two patients, sustained molecular remission wets observed , The factors that were correlated with response to DLI were a T-cell dose of more than 1.10(8) cells/kg, response to reinduction therapy, and chemoth erapy-sensitive disease before AlloSCT. Conclusion: These data confirm the potential and durable graft-versus-myelo ma effect of DLI in patients with relapsed MM after AlloSCT, future studies should be aimed at increasing response rates, especially in patients with chemoresistant disease, and reducing toxicity by limiting GVHD. Adjuvant DL I seems an attractive and promising approach for patients who do not achiev e a molecular remission after AlloSCT. (C) 2000 by American Society of Clin ical Oncology.