Allografting after nonmyeloablative conditioning as a treatment after a failed conventional hematopoietic cell transplant.

Outcomes with conventional allogeneic hematopoietic cell transplantation (HCT) after failed HCT are typically poor. To reduce transplantation-related mortality (TRM), 55 patients (median age, 43 years; range, 18-69 years) who had failed conventional autologous (n = 49), allogeneic (n = 4), or syngeneic (n = 2) HCT received human leukocyte antigen-matched related (n = 31) or unrelated (n = 24) donor allografts after nonmyeloablative conditioning with 2 Gy of total body irradiation or 2 Gy of total body irradiation and 90 mg/m(2) of fludarabine. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. One rejection occurred. Thirty-three patients died a median of 127 days (range, 7-834 days) after HCT: 21 of relapse, 11 of TRM, and 1 of suicide. The TRM rate on day 100 was 11% with an estimated 1-year TRM rate of 20% (95% confidence interval [CI], 9% to 31%). The median follow-up among the 22 survivors is 368 days (range, 173-796 days). Seventeen of 22 survivors are progression-free. One-year estimates of overall and progression-free survival rates are 49% (95% CI, 35% to 62%) and 28% (95% CI, 16% to 41%), respectively. Untreated disease at the time of allografting after nonmyeloablative conditioning increased the risk of death (hazard ratio = 2.4; P =.04). Although the length of follow-up is still short, it appears that encouraging outcomes can be achieved with nonmyeloablative conditioning in patients expected to have poor outcomes with conventional allografting.