1. ¹Department of Medicine, Baylor College of Medicine, Houston, TX, USA
2. ²Center for Gene and Cell Therapy, Baylor College of Medicine, Houston, TX, USA
3. ³The Methodist Hospital, Houston, TX, USA
4. ⁴Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA

Correspondence: Dr U Popat, Center for Cell and Gene Therapy, Baylor College of Medicine, 6565 Fannin, M964, Houston, TX 77030, USA. E-mail: upopat@bcm.tmc.edu

Received 30 September 2004; Accepted 6 January 2005; Published online 18 April 2005.

Abstract

Allogeneic hemopoietic stem cell transplantation (HSCT) is the only curative option for many patients with hematological malignancies. Since many of these patients lack HLA-identical sibling donors and are older or have comorbidity, a fully ablative HSCT is not feasible and an alternative approach is required. We studied 22 consecutive patients who could not have myeloablative conditioning because of comorbidity or age – 21/22 being over the age of 50 years (median 58 years range 20–70 years). A conditioning regimen consisting of fludarabine, total body radiation 450 cGy and alemtuzumab (CD52 mAb) was used for 15 patients. A second group of seven patients received CD45 monoclonal antibodies in addition. Unrelated donor stem cells were HLA matched (15 patients – 68%) or one locus mismatched (seven patients – 32%). In all, 16 patients had high-risk disease, including 12 with active malignancy at the time of transplant. With a median follow-up of 715 (216–1470) days, nonrelapse mortality, actuarial event-free and overall survival is 27, 45 and 45%, respectively. Hence the outcome of reduced intensity HSCT with lymphodepleting antibodies in older patients with intermediate/high-risk hematological malignancies appears comparable to that obtained with fully ablative transplantation in younger patients, even when these older recipients lack HLA-identical sibling donors.