Researchers have shown greatly improved outcomes in using stem cell transplantation to treat patients with juvenile myelomonocytic leukemia (JMML), a very rare form of chronic blood cancer. Their findings were published in a letter to Blood (2015; doi:10.1182/blood-2015-05-644161).
Allogeneic hematopoietic stem cell transplantation (HSCT) involves the transplantation of stem cells from a donor, which may be derived from bone marrow, peripheral blood, or umbilical cord blood. The recipient’s immune system is usually destroyed with radiation or chemotherapy before the transplantation.
Allogeneic HSCT is the only reported cure for JMML; however, best outcomes of the therapy have shown that cure is achieved in only half of patients with the disease. According to the researchers, there is currently no standard conditioning regimen for children with JMML undergoing HSCT.
This study, conducted by researchers in the Division of Hematology, Oncology and Blood & Marrow Transplantation at Children’s Hospital Los Angeles (CHLA) in California and led by Hisham Abdel-Azim, MD, looked at children with JMML who underwent HSCT at Children’s Hospital Los Angeles. All of the seven patients were alive and in clinical remission at a median follow-up of 25.3 months. Their average age was 2.6 years.
“The lack of transplant-related mortality in the group of children we studied at the Children’s Center for Cancer and Blood Diseases at CHLA suggests that BUMEL [intravenous busulfan and melphalan] may represent a successful HSCT high-dose chemotherapy regimen,” said Abdel-Azim. “It is also possible that administering conventional dose chemotherapy, before HSCT, to patients with more progressive disease may have contributed to the improved outcomes.”
He added that a follow up clinical trial is warranted to confirm these promising findings.