Hematopoietic stem cell transplantation is a treatment method in which blood containing the cells that produce blood (hematopoietic stem cells) is transplanted into a patient for the treatment of leukemia and the like.However, white blood cells transplanted from a healthy person (donor) attack the patient's normal somatic cells, causing a serious immune abnormality called "graft-versus-host disease (GVHD)" and causing diarrhea, skin, and liver damage. May cause. Administration of a potent immunosuppressant to prevent GVHD also suppresses the "graft-versus-tumor (GVT) effect" (attacking of donor white blood cells against cancer cells), resulting in recurrence of blood cancer after transplantation. There is.Therefore, there has long been a need for a method of preserving the GVT effect while suppressing GVHD.

　The research group has focused on trametinib, a treatment for skin cancer (melanoma) found in Japan, and has been conducting research.As a result of animal experiments, it was discovered for the first time in the world that trametinib suppresses troublesome GVHD at the time of transplantation, but does not suppress the GVT effect that is important for curing cancer, and prevents the recurrence of cancer.

　Trametinib has already been approved in both Japan and the United States as a treatment for skin cancer, and its safety has been proven.Therefore, we plan to start clinical trials in hematopoietic stem cell transplant patients suffering from GVHD as soon as possible.It has the potential to be applied to organ transplants (kidney transplants, liver transplants, etc.).