1. ¹Hematology Branch, NHLBI, National Institutes of Health, Bethesda, MD, USA
2. ²Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD, USA

Correspondence: Dr AJ Barrett, Stem Cell Allogeneic Transplantation Section, Hematology Branch, NHLBI, NIH, Building 10, Hatfield CRC, Room 3-5320, 10 Center Drive MSC 1202, Bethesda, MD 20892-1202, USA. E-mail: barrettj@nhlbi.nih.gov

Received 3 June 2005; Accepted 16 August 2005; Published online 3 October 2005.

Abstract

Donor lymphocyte infusions (DLI) have been the mainstay of treatment for chronic myeloid leukemia (CML) relapsing after allogeneic stem cell transplantation (allo-SCT). Imatinib mesylate (IM) is also effective in these patients. However, advanced phase relapse (APRel) responds poorly with either treatment. To test the possibility that combinations of DLI and IM might be more effective, 37 patients with CML relapsing after allo-SCT between August 1994 and May 2004 were studied. Ten had molecular relapse (MRel), 14 hematological relapse (HRel) and 13 APRel. Thirteen received DLI, 9 IM and 11 DLI+IM. Four patients received DLI+IM but not concurrently. Thirty (81%) patients responded (actuarial survival and current leukemia-free survival of 80.66.7% and 69.17.7%). Of 30 patients, 26 are in molecular remission (MR), median follow-up of 1226 days (range 249–3257) since relapse. Ten of 11 patients (including four with APRel) treated with DLI+IM achieved MR in 3 months and all are alive in MR. In contrast, only two of 22 treated with either modality (1/13 DLI and 1/9 IM) achieved MR at 3 months, 15 are alive, 11 in MR. Four patients receiving nonconcurrent DLI+IM are also alive in MR. In conclusion, DLI appears to synergize with IM to induce rapid and durable MR.