Second Hematopoietic Stem Cell Transplantation for Leukemia Relapsing after Myeloablative T Cell Depleted Transplants Does Not Prolong Survival

Patients with leukemia relapsing after allogeneic hematopoietic stem cell transplantation (SCT) have a dismal prognosis. A second SCT offers a further opportunity for cure, but has a high rate of treatment failure. To determine the utility of this option, we analyzed 59 consecutive patients relapsing after a myeloablative HLA-matched sibling T cell depleted SCT. Twenty five patients (13 relapsing within 6 months and 12 relapsing between 6 – 170 months after the first SCT) received a T-replete second SCT. Thirty-eight patients relapsing early had a shorter survival than the 21 patients relapsing later (median 96 vs 298 days, p = 0.0002). In patients relapsing early, the second SCT did not improve overall survival compared to patients receiving non-SCT treatments (median survival 109 vs 80 days, p = 0.41). In patients relapsing late, despite an early trend in favor of second SCT, overall survival was comparable for patients receiving a second SCT compared with patients not retransplanted (median survival 363.5 vs 162 days, p = 0.49). Disappointingly our results do not demonstrate an important survival benefit for a second T-replete allogeneic SCT to treat relapse following a T cell depleted SCT.