Allogeneic Haploidentical Blood or Marrow Transplantation with Post-Transplant Cyclophosphamide in Chronic Lymphocytic Leukemia.

Abstract Allogeneic blood or marrow transplantation (alloBMT) remains the only treatment for chronic lymphocytic leukemia (CLL) with curative potential. While post-transplant cyclophosphamide (PTCy) reduces alloBMT toxicity by decreasing graft-versus-host disease (GVHD), its effect on CLL alloBMT outcomes is unknown. We studied 64 consecutive CLL patients undergoing non-myeloablative (NMA) haploidentical alloBMT at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center. The 4-year overall survival (OS) was 52% (95% confidence interval [CI]: 40-68%) and progression free survival (PFS) was 37% (95% CI: 26-54%) for all 64 patients undergoing alloBMT. In total, 6 patients suffered from engraftment failure. PTCy prophylaxis was associated with a modest cumulative GVHD incidence: 27% (95% CI: 15-38%) 1-year grade II-IV acute GVHD, and 17% (95% CI: 7-26%) 2-year chronic GVHD. We demonstrate NMA haploidentical alloBMT with PTCy is a safe and effective treatment option.