Simultaneous Control of Third-Degree Graft-Versus-Host Disease and Prevention of Recurrence of Juvenile Myelomonocytic Leukemia (JMML) With 6-Mercaptopurine Following Fulminant JMML Relapse Early After KIR Mismatched Bone Marrow Transplantation

Abstract

The authors describe a young boy with juvenile myelomonocytic leukemia (JMML) who relapsed 45 days after HLA and killer immunoglobulin-like receptor (KIR) mismatched unrelated donor bone marrow transplant (MMUD-BMT) and subsequently developed life-threatening graft-versus-host disease (GvHD). Treatment with 6-mercaptopurine (6-MP) appeared to control severe GvHD and possibly prevented recurrence of leukemic relapse.

6-Mercaptopurine to Induce Remission Despite Graft Failure Post Hematopoietic Cell Transplantation for Juvenile Myelomonocytic Leukemia

“…5 The second patient attained remission and control of GvHD with the use of 6-MP, suggesting the GvL effect. 6 In conclusion, this is the first description of JMML patient attains remission with 6-MP post-HCT despite GF and no GvL effect. This report highlights the importance of 6-MP as an agent targeting JMML clones.…”

“…The first patient’s remission was thought to be due to the possibility that myeloablative chemotherapy eradicated the JMML clone 5. The second patient attained remission and control of GvHD with the use of 6-MP, suggesting the GvL effect 6…”

Juvenile Myelomonocytic Leukemia: Molecular Pathogenesis Informs Current Approaches to Therapy and Hematopoietic Cell Transplantation

“…Examples include the mTOR inhibitor sirolimus (74) for acute or chronic GVHD, or dasatinib (75) for chronic GVHD, both which has been shown in vitro to directly inhibit growth of some cases of JMML. Another interesting approach described in one case report is to utilize 6-mercaptopurine for control of both acute GVHD and JMML (76). …”