Universal posttransplant cyclophosphamide after allogeneic transplant, a retrospective single institution study.

BACKGROUND: The excellent results of posttransplant cyclophosphamide in decreasing graft-versus-host disease (GVHD) after haploidentical (HI) allogeneic transplant have challenged current donor selection algorithms. PATIENTS AND METHODS: We compared outcomes after matched sibling (MSD) versus alternative donor transplant using identical graft-versus-host disease (GVHD) prophylaxis including posttransplant cyclophosphamide (PTCy. Endpoints included engraftment, time outside of the hospital in the first 100 days after transplant, overall survival (OS), non-relapse mortality (NRM) and percentage of patients disease-free and off immunosuppression (DFOI) at one year and at the last follow-up. RESULTS: There were significant differences at baseline between matched donor versus HI donor transplants with higher disease-risk index (DRI), more female-to-male donor recipient pairs and a higher percentage of Black patients in the HI group. Engraftment and time out of the hospital favored MSD and matched unrelated donor transplants. Multivariate analysis showed that high DRI and Black race were associated with decreased survival and Black race was associated with a higher NRM. CONCLUSIONS: With the use of PTCy, our results support current donor selection algorithms. The finding of decreased survival and increased NRM in Black patients requires confirmation in a larger number of patients as well as the development of mitigation strategies.

Incorporation of posttransplant cyclophosphamide as part of standard immunoprophylaxis for all allogeneic transplants: a retrospective, single institution study.

The addition of posttransplant cyclophosphamide (PTCy) to standard graft-versus-host disease (GVHD) prophylaxis following haploidentical blood stem transplants has resulted in relatively low rates of GVHD. As GVHD remains a major cause of morbidity and mortality in patients receiving transplants from matched donors, we began to use PTCy in all blood stem cell transplants in 2016 and compared our recent experience with PTCy after matched sibling and unrelated donor transplants (N = 49) to the earlier 2-year period (N = 41) when PTCy was not used. Endpoints included graft-versus-host, relapse-free-survival (GRFS), overall survival, non-relapse mortality, and percentage of patients disease-free and off immunosuppression (DFOI) at 1 year and at the last follow-up. The difference in GRFS between the standard and the PTCy cohort was not statistically significant. There was a statistically improved relapse-free and overall survival in the PTCY cohort that was due to a significant decrease in non-relapse mortality secondary to GVHD. There was also a borderline statistically improved DFOI at 1 year and at last follow-up in the PTCY group. These results suggest that PTCy after HLA-matched transplants provides at least comparable efficacy to other GVHD strategies and may allow more frequent discontinuation of immunosuppression.

Lactobacillus rhamnosus GG probiotic enteric regimen does not appreciably alter the gut microbiome or provide protection against GVHD after allogeneic hematopoietic stem cell transplantation.

Graft-versus-host disease (GVHD) is a major adverse effect associated with allogeneic stem cell transplant. Previous studies in mice indicated that administration of the probiotic Lactobacillus rhamnosus GG can reduce the incidence of GVHD after hematopoietic stem cell transplant. Here we report results from the first randomized probiotic enteric regimen trial in which allogenic hematopoietic stem cell patients were supplemented with Lactobacillus rhamnosus GG. Gut microbiome analysis confirmed a previously reported gut microbiome association with GVHD. However, the clinical trial was terminated when interim analysis did not detect an appreciable probiotic-related change in the gut microbiome or incidence of GVHD. Additional studies are necessary to determine whether probiotics can alter the incidence of GVHD after allogeneic stem cell transplant.