Menatetrenone, a vitamin K2 analog, ameliorates cytopenia in patients with refractory anemia of myelodysplastic syndrome.

Vitamin K2 induces differentiation of leukemic cell lines and apoptosis of immature blasts in myelodysplastic syndrome (MDS). We recently reported a case of MDS-refractory anemia (MDS-RA) with trilineage hematologic response to oral administration of menatetrenone, a vitamin K2 analog. To determine a possible role of this agent in treatment of MDS-RA, we conducted a prospective randomized trial assessing the safety and efficacy of menatetrenone. A total of 18 consecutive patients newly diagnosed with MDS-RA were randomized to receive either 45 mg of oral menatetrenone (group 1) or no menatetrenone (group 2). Administration of menatetrenone was well tolerated. Of the nine patients in group 1 (56%), five improved with menatetrenone treatment while only one (11%) of the group 2 patients improved. Three patients (33%) showed a major response in absolute neutrophil count (ANC), two (22%) showed a major response in hemoglobin concentration, and two of the nine (22%) showed a major response in platelet count. The ANC of group 1 patients rose after treatment, while that of group 2 patients decreased slightly at follow-up after 16 weeks ( p=0.03). Significant improvement was also seen in final platelet count ( p=0.01), but not in hemoglobin concentration. Given the absence of toxicity, menatetrenone can be recommended for all patients with MDS-RA.