Long-term follow-up of patients with CLL treated with allogeneic hematopoietic transplantation

Background: We investigated the long-term outcome of allogeneic stem-cell transplantation after myeloablative conditioning regimen as treatment for patients with chronic lymphocytic leukemia. Methods: Patients were eligible for our study if they were refractory or failed a prior response to fludarabine. The conditioning regimen consisted of high-dose CY 60 mg/kg daily for 2 days and fractionated TBI. One patient received BEAM because of prior radiation. GvHD prophylaxis consisted of CYA or tacrolimus and MTX in the majority of patients. Results: Twenty eight patients were treated, nineteen had disease that was refractory to fludarabine. The median number of prior chemotherapy regimens per patient was 3. Twenty had HLA-identical donors and one had a one-Ag mismatched sibling donor. Seven patients had a matched unrelated transplant. The median follow-up time for the surviving patients was 66 months. By univariate analysis, chemosensitivity was the only factor that predicted a better outcome. For the chemosensitive patients, the overall survival was 78%, compared with 31% for those with refractory disease (P = 0.05). Progression-free survival at 5 years was 78% for the chemosensitive and 26% for those who were refractory to conventional chemotherapy at the time of transplantation (P = 0.03). Three patients (11%) died within 100 days of transplant. The actuarial risk of acute Grade II-IV GvHD was 49%. Only one patient developed acute Grade III GvHD. Conclusion: Allogeneic transplantation is probably curative for a subset of patients with chronic lymphocytic leukemia. Patients should be considered for clinical trials involving allogeneic transplantation at an earlier stage prior acquiring chemorefractoriness.