Thiotepa-Based Intensified Reduced-Intensity Conditioning Adult Double-Unit Cord Blood Hematopoietic Stem Cell Transplantation Results in Decreased Relapse Rate and Improved Survival Compared with Transplantation Following Standard Reduced-Intensity Conditioning: A Retrospective Cohort Comparison

Biol Blood Marrow Transplant. 2018 Aug;24(8):1671-1677. doi: 10.1016/j.bbmt.2018.04.019. Epub 2018 Apr 21.

Abstract

The "Minnesota" reduced-intensity conditioning (RIC) cord blood transplantation (CBT) regimen (standard RIC) of fludarabine (Flu) (200 mg/m2), cyclophosphamide (Cy) (50 mg/kg), and 200- or 300-cGy total body irradiation (TBI) is the most published RIC CBT regimen. Though well tolerated, high relapse rates remain a concern with this regimen. Intensification of conditioning may reduce relapse without increasing transplant-related mortality (TRM). We performed a retrospective cohort comparison of outcomes in adult patients who underwent first double-unit CBT with standard RIC as compared with the intensified regimen of Flu 150 mg/m2, Cy 50 mg/kg, thiotepa 10 mg/kg, and 400-cGy TBI (intensified RIC). Of the 99 patients studied, 47 received intensified RIC. Acute myelogenous leukemia was the major indication for transplant. The median age at transplant was 67 years (range, 24 to 74 years) and 54 years (range, 25 to 67 years) in standard RIC and intensified RIC, respectively. Median hematopoietic stem cell transplantation comorbidity index was 3 (range, 0 to 5) and 1 (range, 0 to 6) in the standard RIC and intensified RIC groups, respectively. Median follow-up among survivors was 22 months (range, 3.7 to 79 months) following standard RIC and 15 months (range, 2.8 to 36 months) following intensified RIC. The cumulative incidence (CI) of relapse was significantly lower following intensified RIC compared with standard RIC (P = .0013); this finding maintained significance in multivariate analysis (P = .045). TRM was comparable between the 2 groups (P = .99). Overall survival (OS) was significantly improved following intensified RIC as compared with standard RIC (P = .03). Median OS was 17 months following standard RIC versus not reached followed intensified RIC. The CI of grade II to IV acute graft-versus-host disease (GVHD) was significantly higher in the intensified RIC cohort than the standard RIC-cohort (P = .007), while CI of grade III to IV acute GVHD, any chronic GVHD, and moderate-to-severe chronic GVHD was comparable in each cohort (P = .20, P = .21, and P = .61, respectively). This retrospective analysis shows an improvement in OS and decreased relapse without increase in TRM in patients receiving intensified RIC as compared with standard RIC. Our data suggest that consideration of thiotepa-based intensified RIC may improve outcomes in fit, older patients undergoing double-unit CBT.

Keywords: Cord blood transplantation; Intensified RIC; Reduced intensity conditioning; Thiotepa.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Cord Blood Stem Cell Transplantation / adverse effects
  • Cord Blood Stem Cell Transplantation / methods*
  • Cord Blood Stem Cell Transplantation / mortality
  • Female
  • Graft vs Host Disease / etiology
  • Graft vs Host Disease / mortality
  • Humans
  • Leukemia, Myeloid, Acute / mortality
  • Leukemia, Myeloid, Acute / pathology
  • Leukemia, Myeloid, Acute / therapy
  • Male
  • Middle Aged
  • Myeloablative Agonists / therapeutic use
  • Recurrence
  • Retrospective Studies
  • Survival Analysis
  • Thiotepa / therapeutic use*
  • Transplantation Conditioning / adverse effects
  • Transplantation Conditioning / methods*
  • Transplantation Conditioning / mortality
  • Vidarabine / analogs & derivatives
  • Vidarabine / therapeutic use
  • Whole-Body Irradiation
  • Young Adult

Substances

  • Myeloablative Agonists
  • Thiotepa
  • Vidarabine
  • fludarabine