Novel immunosuppression compounds and experimental therapies for chronic graft-versus-host disease

Chronic graft-versus-host disease (GVHD) is a severe complication of allogeneic stem cell transplantation, with a substantial impact on the quality of life and survival, still lacking with regard to an optimal therapeutic strategy. Corticosteroids are considered the standard of care for first-line treatment of chronic GVHD, but only a minority of the patients responds to them durably. Management of steroid-refractory chronic GVHD is not well defined. This review surveys novel treatment strategies, such as therapies that expand regulatory T cells, target B cells or target the processes implicated in fibrosis that may allow more effective control of chronic GVHD in the future. Most therapies are based solely on phase II trials or on retrospective analyses with a wide range of overall responses. Large, well-designed prospective studies are eagerly needed to establish better treatments, as well as valid biomarkers to identify the likelihood of the response to a drug in advance.