Azacitidine as a bridge to transplantation in juvenile myelomonocytic leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for most patients, but no appropriate pre-HSCT bridging therapy has been established. Since Furlan et al 1 reported the effectiveness of azacitidine in pre-HSCT JMML, several reports have been published. Molecular analysis identified a KRAS p.G13D mutation in peripheral blood mononuclear cells. Table 1 Clinical course At diagnosis Before AZA 1st cycle 2nd cycle 3rd cycle 4th cycle 5th cycle 6th cycle 7th cycle 8th cycle Before HSCT WBCs (/μL) 18 500 5,700 4,500 5,200 4,400 4,200 3,000 3,300 2,700 3,400 3,300 Monocytes (/μL) 8,510 2,907 675 1,664 968 882 180 231 297 68 198 % Blasts (PB) 2 1 4 2 2 3 1 0 0 0 0 % Blasts(BM) 8.2 – 3 – – – – – – – 1.4 % Monosomy7 (PB; FISH) 77 – 23 46 35 28 47 13 14 – 9 % Monosomy7 (BM; FISH) 93 – 92 – – – – – – – 28 Platelet (×104/μL) 1.7 1.8 1.6 3.5 8.3 4.7 5.1 6.7 14.9 12.1 18.1 Liver*1 (cm) 4 10 8 7 6 6 6 3 0 0 0 Spleen*2 (cm) 0.5 10 8 7 6 6 6 3 1 0 0 Platelet infusion Once a day Once a day Every 2 days Every 2 days Every 3 days Every 3 days Every 3 days No No No No *1below right costal margin *2below left costal margin Abbreviations: AZA, azacitidine; BM, bone marrow; FISH, fluorescent in situ hybridization; HSCT, hematopoietic stem cell transplantation; PB, peripheral blood; WBC, white blood cell.