Cytosine arabinoside and mitoxantrone followed by second allogeneic transplant for the treatment of children with refractory juvenile myelomonocytic leukemia.

Hematopoietic stem cell transplantation (HSCT) remains the only curative option for most patients with juvenile myelomonocytic leukemia (JMML). However, persistent disease and relapse rates after transplant range from 26% to 58%. We report the successful use of second HSCT after preparation with mitoxantrone and cytosine arabinoside (Ara-C) for patients with refractory or recurrent disease. Between 1993 and 2006, 5 children who underwent HSCT at our institution as initial therapy for JMML had persistent disease or relapsed. Pre-HSCT conditioning varied and donors were either HLA-matched siblings (n=2) or matched unrelated donors (n=3). After initial HSCT, they subsequently received high-dose Ara-C (3 g/m IV) every 12 hours on days -8 through -3 and mitoxantrone (10 mg/m/d IV) on days -8, -7, -6 followed by second HSCT from their original donors. All 5 patients are alive at 88, 179, 199, 234, and 246 months with no evidence of JMML, no significant toxicity, and 100% donor chimera as determined by PCR short-tandem repeat analysis. Our experience supports second transplant utilizing high-dose Ara-C and mitoxantrone in children with JMML who do not respond or relapse after first transplant.