The relative importance of various human leukocyte antigen (HLA) loci and the resolution level at which they are matched has not been fully defined for unrelated donor transplantation. To address this question, National Marrow Donor Program data from 3857 transplantations performed from 1988 to 2003 in the United States were analyzed. Patient-donor pairs were fully typed for HLA-A, -B, -C, -DRB1, -DQB1, -DQA1, -DPB1, and -DPA1 alleles. High-resolution DNA matching for HLA-A, -B, -C, and -DRB1 (8/8 match) was the minimum level of matching associated with the highest survival. A single mismatch detected by low- or high-resolution DNA testing at HLA-A, -B, -C or -DRB1 (7/8 match) was associated with higher mortality (relative risk, 1.25; 95% CI, 1.13-1.38; P < .001) and 1-year survival of 43% compared with 52% for 8/8 matched pairs. Single mismatches at HLA-B or HLA-C appear better tolerated than mismatches at HLA-A or HLA-DRB1. Mismatching at 2 or more loci compounded the risk. Mismatching at HLA-DP or -DQ loci and donor factors other than HLA type were not associated with survival. In multivariate modeling, patient age, race, disease stage, and cytomegalovirus status were as predictive of survival as donor HLA matching. High-resolution DNA matching for HLA-A, -B, -C, and -DRB1 alleles is associated with higher rates of survival.

Belumosudil, an investigational oral selective inhibitor of Rho-associated coiled-coil–containing protein kinase 2 (ROCK2), reduces type 17 and follicular T helper cells via downregulation of STAT3 and enhances regulatory T cells via upregulation of STAT5. Belumosudil may effectively treat patients with chronic graft-versus-host disease (cGVHD), a major cause of morbidity and late nonrelapse mortality after an allogeneic hematopoietic cell transplant. This phase 2 randomized multicenter registration study evaluated belumosudil 200 mg daily (n = 66) and 200 mg twice daily (n = 66) in subjects with cGVHD who had received 2 to 5 prior lines of therapy. The primary end point was best overall response rate (ORR). Duration of response (DOR), changes in Lee Symptom Scale score, failure-free survival, corticosteroid dose reductions, and overall survival were also evaluated. Overall median follow-up was 14 months. The best ORR for belumosudil 200 mg daily and 200 mg twice daily was 74% (95% confidence interval [CI], 62-84) and 77% (95% CI, 65-87), respectively, with high response rates observed in all subgroups. All affected organs demonstrated complete responses. The median DOR was 54 weeks; 44% of subjects have remained on therapy for ≥1 year. Symptom reduction with belumosudil 200 mg daily and 200 mg twice daily was reported in 59% and 62% of subjects, respectively. Adverse events (AEs) were consistent with those expected in patients with cGVHD receiving corticosteroids and other immunosuppressants. Sixteen subjects (12%) discontinued belumosudil because of possible drug-related AEs. Belumosudil, a promising therapy for cGVHD, was well tolerated with clinically meaningful responses. This trial was registered at www.clinicaltrials.gov as #NCT03640481.

Chronic graft versus host disease (GVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. Clinically, chronic GVHD is a pleiotropic, multiorgan syndrome involving tissue inflammation and fibrosis that often results in permanent organ dysfunction. Chronic GVHD is fundamentally caused by replacement of the host’s immune system with donor cells, although the heterogeneity of clinical manifestations suggests that patient, donor, and transplant factors modulate the phenotype. The diagnosis of chronic GVHD and determination of treatment response largely rely on clinical examination and patient interview. The 2005 and 2014 National Institutes of Health Consensus Development Projects on Criteria for Clinical Trials in Chronic GVHD standardized the terminology around chronic GVHD classification systems to ensure that a common language and procedures are being used in clinical research. This review provides a summary of these recommendations and illustrates how they are being used in clinical research and the potential for their use in clinical care.

Chronic graft-versus-host disease (GVHD) is an immune-mediated disorder that occurs frequently after allogeneic hematopoietic cell transplantation (HCT). Most cases are diagnosed within the first year at a median of 4 to 6 months after HCT, but 5–10% of cases are initially diagnosed beyond the first post-transplant year. Chronic GVHD most often involves the skin and mouth, but almost any other organ system can be involved. Correct diagnosis is critical so that appropriate therapy can be started promptly to minimize symptoms and prevent irreversible organ damage. Initial treatment should be with cortico-steroid-based therapy. Optimal secondary treatment as not been established, although a large number of agents may provide benefits. A 2004 NIH conference focused on development of consensus criteria for chronic GVHD. Six papers published in 2005 and 2006 propose consensus definitions for chronic GVHD diagnosis and scoring, pathology, biomarkers, response criteria, supportive care and design of clinical trials. This review will focus on common clinical presentations and principles for managing chronic GVHD. The most frequently used secondary therapies and ongoing trials are summarized. New concepts from the NIH consensus conference are discussed.

In 2005, the National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic GVHD proposed a new scoring system for individual organs and an algorithm for calculating global severity (mild, moderate, severe). The Chronic GVHD Consortium was established to test these new criteria. This report includes the first 298 adult patients enrolled at 5 centers of the Consortium. Patients were assessed every 3-6 months using standardized forms recommended by the Consensus Conference. At the time of study enrollment, global chronic GVHD severity was mild in 10% (n = 32), moderate in 59% (n = 175), and severe in 31% (n = 91). Skin, lung, or eye scores determined the global severity score in the majority of cases, with the other 5 organs determining 16% of the global severity scores. Conventional risk factors predictive for onset of chronic GVHD and nonrelapse mortality in people with chronic GVHD were not associated with NIH global severity scores. Global severity scores at enrollment were associated with nonrelapse mortality (P < .0001) and survival (P < .0001); 2-year overall survival was 62% (severe), 86% (moderate), and 97% (mild). Patients with mild chronic GVHD have a good prognosis, while patients with severe chronic GVHD have a poor prognosis. This study was registered at www.clinicaltrials.gov as no. NCT00637689.