Second allogeneic stem cell transplantation can rescue a significant proportion of patients with JMML relapsing after first allograft
Abstract
Juvenile myelomonocytic leukemia (JMML) is a rare myeloproliferative disease of early childhood. More than 90% of patients harbor mutations in PTPN11, KRAS, NRAS, CBL, or NF1.
For most patients, allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy, while relapse is the major cause of treatment failure recorded in about 35% of patients. Age >=2 years, high hemoglobin F (HbF), secondary clonal aberrations, and DNA hypermethylation are associated with an increased risk of relapse.
Treatment options for recurrent JMML are limited; for patients still on immunosuppressive therapy, discontinuation of all immunosuppressing agents is generally the first intervention. Donor leukocyte infusions (DLI) can induce a response in some relapsed patients, but the overall outcome of DLI as single strategy has been unfavorable.
Few data are available on the efficacy and safety of second HSCT in JMML. We analyzed the outcome of 68 children with JMML who relapsed after first HSCT and received a second allograft.