A randomized study of alfacalcidol in the refractory myelodysplastic anaemias. A Japanese cooperative study.

A multi-institutional randomized trial of alfacalcidol (1 alpha hydroxyvitamin D3) was performed to determine the therapeutic effect of alfacalcidol in patients with refractory myelodysplastic anaemias. Twenty-three evaluable patients were randomized to receive either a single daily oral dose of 6 micrograms of alfacalcidol or only supportive care as a control. Treatment was continued, whenever possible, for a period of 6 months. Response was assessed by weekly blood counts, clinical course and repeated marrow examinations. No significant difference was noted between the alfacalcidol and control groups. Three of the 13 patients in the alfacalcidol group, and two of the 10 patients in the control group, suffered a progression of their disease. One patient with refractory anaemia showed a good response to alfacalcidol in all three haematopoietic cell lineages; the response, however, could not be maintained, because discontinuation of the drug resulted in a worsening of pancytopenia which was refractory to a second course of alfacalcidol therapy. Hypercalcaemia was the major toxic side-effect of alfacalcidol therapy. The results indicate that alfacalcidol therapy, when used alone, does not induce a beneficial effect in patients with refractory myelodysplastic anaemias.