Feasibility of Low-Dose Interleukin-2 Therapy Following T-Cell-Depleted Nonmyeloablative Allogeneic Hematopoietic Stem Cell Transplantation From HLA-Matched or -Mismatched Family Member Donors

Abstract

Introduction: High relapse rates and infections remain primary causes of failure in nonmyeloablative transplantation. Interleukin-2 (IL-2) may stimulate the immune system and improve outcomes. The primary objective of this pilot study was to evaluate the feasibility of administering IL-2 following a T-cell-depleted nonmyeloablative hematopoietic stem cell transplant. Methods: Patients received T-cell-depleted nonmyeloablative transplant from a matched or mismatched related donor. Those with allogeneic engraftment, <grade 2 acute GVHD at time of study entry, and no severe end organ damage were eligible and received IL-2 starting 6 weeks after the first day of stem cell infusion. Patients received 1 mu/m2 daily for 5 days each week for 4 weeks followed by a 2-week rest period for a 6-week cycle to continue for up to 1 year. Results: Eight patients aged 28–69 years were treated. Significant toxicities were limited to GVHD of the skin ≤grade 2 in 3 patients and severe fatigue in 4 patients, limiting the duration of therapy. Two of the 8 patients died of relapsed disease and 1 from CMV. With a median overall duration of follow-up of survivors of 48 months, 5 patients (63%) remain alive and in continuous complete remission.

Keywords: :

• Nonmyeloablative Allogeneic Transplantation
• Leukemia/Lymphoma
• IL-2
• NK cells

ACKNOWLEDGMENTS

We acknowledge and thank our residents, fellows, and nurses in the Bone Marrow Transplant Unit for the fine care of our patients, as well as the cooperation and support of our referring physicians. This research was supported in part by the NIH; grant nos. 5K23RR16063-01 (DAR), 2PO-1CA47741 (NJC), M01-RR30 (NCRR, Clinical Research), Schering Plough, Inc.; and the Leukemia and Lymphoma Society (DAR).