A Multicenter Phase II Clinical Trial of Low-Dose Subcutaneous Decitabine in Myelofibrosis.

Myelofibrosis (MF) in the chronic phase is a challenging disease entity to treat, and conventional treatment options are geared towards symptom palliation. In this prospective, multicenter, phase II trial, 21 patients with myelofibrosis (18 chronic-phase, 2 accelerated-phase, 1 blast-phase) were treated with a 10-day schedule of subcutaneous decitabine at 0.3 mg/kg/day. The overall response rate was 33% (95% CI, 15-57), primarily manifested as an improvement in cytopenias. The median duration of response was 7 months (range, 3-44). A high IPSS risk score, high baseline fetal hemoglobin level, and sustained decreases in circulating CD34+ cell counts were associated with response to decitabine. All patients experienced at least one grade 3 or 4 cytopenia. Non-hematologic toxicities were less frequent, with fatigue, anorexia, and hypocalcemia being the most common. Given the lack of effective therapies in myelofibrosis with severe cytopenias, this study supports further investigation into the use of hypomethylating agents as single agents or in combination therapies. NCT00095784.