All-trans retinoic acid: tolerance and biologic effects in myelodysplastic syndrome.

PURPOSE: We conducted a study to evaluate the tolerance to and biologic effects of all-trans retinoic acid in patients with myelodysplastic syndrome. PATIENTS AND METHODS: Thirty-nine patients with myelodysplastic syndrome were treated with oral all-trans retinoic acid for 6 weeks. Dose levels were 10, 25, 50, 100, 150, 200, and 250 mg/m2/d. At least three patients were treated on each dose level. RESULTS: The most common side effects were mucocutaneous dryness and erythema, and hypertriglyceridemia. Dose-limiting side effects were diverse and included dermatitic problems, sensorineural hearing loss, headaches, nausea and vomiting, myalgias, and dyspnea. The maximum-tolerated dose was 150 mg/m2/d. Only one response was seen among 29 patients considered assessable for response. CONCLUSION: All-trans retinoic acid can be safely administered to patients at doses up to 150 mg/m2/d for 6 weeks. However, as administered in this study, this compound does not appear to have significant activity in myelodysplastic syndromes.