Acute graft-versus-host disease (aGVHD) is one of the most frequent complications after allogeneic hematopoietic stem cell transplantation (HSCT). First-line therapy for aGVHD usually consists of corticosteroids, but almost half of patients fail to respond, and more than 60% eventually die. Although several treatment options have been developed as second-line therapy, currently, no established strategy for steroid-refractory (SR) aGVHD is available. Mesenchymal stem cells (MSCs) have unique immunoregulatory properties that make them attractive for use in salvage therapy for SR-aGVHD. Following the striking clinical course reported by Le Blanc’s group, many clinical trials have shown favorable results of MSC infusions for SR-aGVHD. In Japan, two clinical trials were performed. Following the favorable results of clinical studies, MSCs have become the first approved stem cell drug for SR-aGVHD. This therapy is called TEMCELL. In this review, we briefly summarize the current status and problems with MSCs in Japan. Now that this cell drug is available to all eligible patients, a post-marketing study is needed to answer crucial clinical questions.
2017 The Japan Society for Hematopoietic Stem Cell Transplantation