Salvage Cord Blood Transplantation Using a Short-term Reduced-intensity Conditioning Regimen for Graft Failure

Abstract

Objective Graft failure (GF) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT). A standardized conditioning regimen and an appropriate graft source of salvage HSCT for GF have not yet been established. Some case series have shown good hematopoietic recoveries after salvage HSCT using a short-term reduced-intensity preparative regimen consisting of fludarabine (30-90 mg/m 2 ), cyclophosphamide (2 g/m 2 ), and total-body irradiation (2 Gy). However, the dose of fludarabine has varied in these reports based on the clinical condition of the patients, resulting in very limited experiences with each dose of fludarabine. Methods We retrospectively analyzed 10 patients who developed GF after allogeneic HSCT and underwent salvage cord blood transplantation (CBT) using the above-mentioned conditioning regimen with a fixed dose (90 mg/m 2 ) of fludarabine. Results Eight patients (80.0%) achieved neutrophil engraftment within 30 days from salvage HSCT with a median of 21 (range, 17-23) days. The 1-year overall survival (OS) rate after the salvage HSCT was 50.0%, and the median OS was 281 (range, 23-1,638) days. Cumulative incidences of non-relapse mortality and relapse at 1 year were 50.0% and 10.0%, respectively. Conclusion CBT using this short-term reduced-intensity conditioning regimen may be a promising salvage therapy for GF.

Graft failure after allogeneic hematopoietic stem cell transplantation in pediatric patients with acute leukemia: autologous reconstitution or second transplant?

“…Regarding the optimal conditioning regimen for salvage transplant, several reports have shown favorable outcomes following fludarabine-based reduced-intensity conditioning regimens [ 64 ]. A short-term reduced-intensity conditioning regimen, known as a 'one-day regimen’ including alemtuzumab developed to enhance immunosuppression by T-cell depletion.…”