Low toxicity and favorable overall survival in relapsed/refractory B-ALL following CAR T cells and CD34-selected T-cell depleted allogeneic hematopoietic cell transplant

Bone Marrow Transplant. 2020 Nov;55(11):2160-2169. doi: 10.1038/s41409-020-0926-1. Epub 2020 May 10.


To define the tolerability and outcome of allogeneic hematopoietic stem cell transplant (allo-HSCT) following CAR T-cell therapy, we retrospectively reviewed pediatric/young adult patients with relapsed/refractory B-ALL who underwent this treatment. Fifteen patients (median age 13 years; range 1-20 years) with a median potential follow-up of 39 months demonstrated 24-month cumulative incidence of relapse, cumulative incidence of TRM, and OS of 16% (95% CI: 0-37%), 20% (95% CI: 0-40%), and 80% (95% CI: 60-100%), respectively. Severe toxicity following CAR T cells did not impact OS (p = 0.27), while greater time from CAR T cells to allo-HSCT (>80 days) was associated with a decrease in OS. In comparing CD34-selected T-cell depleted (TCD; n = 9) vs unmodified (n = 6) allo-HSCT, the cumulative incidence of relapse, TRM, and OS at 24 months was 22% (95% CI: 0-49%) vs 0% (p = 0.14), 0% vs 50% [95% CI: 10-90%] (p = 0.02) and 100% vs 50% [95% CI: 10-90%] (p = 0.02). In this small cohort of patients, CAR T cells followed by a CD34-selected TCD allo-HSCT appears to result in less TRM and favorable OS when compared with unmodified allo-HSCT. There was no evidence that disease control was impacted by the type of consolidative allo-HSCT, which demonstrates the feasibility of this approach.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Graft vs Host Disease*
  • Hematopoietic Stem Cell Transplantation*
  • Humans
  • Immunotherapy, Adoptive
  • Infant
  • Neoplasm Recurrence, Local
  • Retrospective Studies
  • T-Lymphocytes
  • Young Adult