Shernan G. Holtan

In patients undergoing allogeneic hematopoietic stem-cell transplantation (HSCT), a calcineurin inhibitor plus methotrexate has been a standard prophylaxis against graft-versus-host disease (GVHD). A phase 2 study indicated the potential superiority of a post-transplantation regimen of cyclophosphamide, tacrolimus, and mycophenolate mofetil. Download a PDF of the Research Summary. In a phase 3 trial, we randomly assigned adults with hematologic cancers in a 1:1 ratio to receive cyclophosphamide–tacrolimus–mycophenolate mofetil (experimental prophylaxis) or tacrolimus–methotrexate (standard prophylaxis). The patients underwent HSCT from an HLA-matched related donor or a matched or 7/8 mismatched (i.e., mismatched at only one of the HLA-A, HLA-B, HLA-C, and HLA-DRB1 loci) unrelated donor, after reduced-intensity conditioning. The primary end point was GVHD-free, relapse-free survival at 1 year, assessed in a time-to-event analysis, with events defined as grade III or IV acute GVHD, chronic GVHD warranting systemic immunosuppression, disease relapse or progression, and death from any cause. In a multivariate Cox regression analysis, GVHD-free, relapse-free survival was significantly more common among the 214 patients in the experimental-prophylaxis group than among the 217 patients in the standard-prophylaxis group (hazard ratio for grade III or IV acute GVHD, chronic GVHD, disease relapse or progression, or death, 0.64; 95% confidence interval [CI], 0.49 to 0.83; P=0.001). At 1 year, the adjusted GVHD-free, relapse-free survival was 52.7% (95% CI, 45.8 to 59.2) with experimental prophylaxis and 34.9% (95% CI, 28.6 to 41.3) with standard prophylaxis. Patients in the experimental-prophylaxis group appeared to have less severe acute or chronic GVHD and a higher incidence of immunosuppression-free survival at 1 year. Overall and disease-free survival, relapse, transplantation-related death, and engraftment did not differ substantially between the groups. Among patients undergoing allogeneic HLA-matched HSCT with reduced-intensity conditioning, GVHD-free, relapse-free survival at 1 year was significantly more common among those who received cyclophosphamide–tacrolimus–mycophenolate mofetil than among those who received tacrolimus–methotrexate. (Funded by the National Heart, Lung, and Blood Institute and others; BMT CTN 1703 ClinicalTrials.gov number, NCT03959241.) QUICK TAKE VIDEO SUMMARYGraft-versus-Host Disease Prophylaxis 02:16

The success of allogeneic hematopoietic cell transplantation (HCT) is typically assessed as individual complications, including graft-versus-host disease (GVHD), relapse, or death, yet no one factor can completely characterize cure without ongoing morbidity. We examined a novel composite end point of GVHD-free/relapse-free survival (GRFS) in which events include grade 3-4 acute GVHD, systemic therapy-requiring chronic GVHD, relapse, or death in the first post-HCT year. In 907 consecutive University of Minnesota allogeneic HCT recipients (2000-2012), 1-year GRFS was 31% (95% confidence interval [CI] 28-34). Regression analyses showed age, disease risk, and donor type significantly influencing GRFS. Adults age 21+ had 2-fold worse GRFS vs children; GRFS did not differ beyond age 21. Adjusted for conditioning intensity, stem cell source, disease risk, age, and transplant year, HLA-matched sibling donor marrow resulted in the best GRFS (51%, 95% CI 46-66), whereas HLA-matched sibling donor peripheral blood stem cells were significantly worse (25%, 95% CI 20-30, P = .01). GRFS after umbilical cord blood transplants and marrow from matched unrelated donors were similar (31%, 95% CI 27-35 and 32%, 95% CI 22-42, respectively). Because GRFS measures freedom from ongoing morbidity and represents ideal HCT recovery, GRFS has value as a novel end point for benchmarking new therapies.

To develop a novel acute graft-versus-host disease (GVHD) risk score, we examined the GVHD clinical stage and grade of 1723 patients at the onset of treatment with systemic steroids. Using clinical grouping, descriptive statistics and recursive partitioning, we identified poorly responsive, high-risk (HR) acute GVHD by the number of involved organs and severity of GVHD at onset. The overall response (complete response/partial response) rate 28 days after initiation of steroid therapy for acute GVHD was lower in the 269 patients with HR-GVHD than in the 1454 patients with standard risk (SR)-GVHD (44% [95% confidence interval (CI) 38% to 50%] versus 68% [95% CI, 66% to 70%], P < .001). Patients with HR-GVHD were less likely to respond at day 28 (odds ratio [OR], .3; 95% CI, .2 to .4; P < .001) and had higher risks of mortality (relative risk, 2.1; 95% CI, 1.7 to 2.6; P < .001) and transplant-related mortality (relative risk, 2.5; 95% CI, 2.0% to 3.2%, P < .001) than patients with SR-GVHD. This refined definition of acute GVHD risk is a better predictor of response, survival, and transplant-related mortality than other published acute GVHD risk scores. Patients with HR-GVHD are candidates for studies investigating new treatment approaches. Likewise, patients with SR-GVHD are candidates for studies investigating less toxic therapy.