Novel regimen for the treatment of juvenile myelomonocytic leukemia (JMML).

The effective treatment for juvenile myelomonocytic leukemia (JMML) patients lacking access to stem cell transplantation remains unavailable. Here, we describe a promising result obtained with novel regimen comprised of a combination of chemotherapy and differentiation therapy. Five patients diagnosed as JMML were treated with a standard regimen (cytosine arabinoside (Ara-C) 100mg/m(2) per day continuous infusion (days 0-6), etoposide 100mg/m(2) per day (days 0-4), vincristine 1.5mg/m(2) per d (day 9) and isotretinoin 75-100mg/m(2) per day (days 10-20)). All patients responded to the standard regimen. Three of the five were later treated with salvage a regimen (Ara-C 100mg/m(2) per day continuous infusion (days 0-4), etoposide 100mg/m(2) per day (days 0-4) and Ara-C 15mg/m(2) per day SC (days 6-15)) when immature myeloid cells reappeared in the peripheral blood, the spleen increased or blast crisis occurred. Immature myeloid cells disappeared again after one cycle of salvage regimen in all patients. All patients are alive now with a median follow up duration of 27 months (8-69 months). Although the number of patients enrolled was limited, the standard and salvage regimens were found to be safe and effective alternatives for JMML patients without a matched donor. These regimens also could be used safely before stem cell transplantation.