13-cis-Retinoic acid treatment in patients with myelodysplastic syndrome.

Twenty patients with primary myelodysplastic syndromes (16 refractory anemia without or with ringed sideroblasts, 2 refractory anemia with excess blasts, 2 refractory anemia with excess blasts in transformation) received 13-cis-retinoic acid at a dosage of 50-100 mg/m2/day for a minimum of 4 weeks. Twelve patients obtained an increase of hemoglobin levels greater than 1 g/dl and 7 showed an associated increase of granulocyte count greater than 50% of baseline values. No significant biochemical signs of dyslipidemia or liver damage were noted. A sustained response was noted only in refractory anemia without or with ringed sideroblasts and normal or hypercellular bone marrow. Five patients are still on therapy from 23 to 82 weeks without transfusion requirement and all have shown an improvement in performance status. We conclude that 13-retinoic acid may only be clinically useful in selected patients since in myelodysplastic syndromes with blast excess the drug does not seem to improve the course of the disease.