Long-term effect of epoetin alfa on clinical and biochemical markers in Friedreich ataxia

Background: Friedreich ataxia is an autosomal recessive disease with no available therapy. Clinical trials with erythropoietin in Friedreich ataxia patients have yielded conflicting results, and the long-term effect of the drug remains unknown. Methods: We designed a double-blind, placebo-controlled, multicenter trial to test the efficacy of epoetin alfa on 56 patients with Friedreich ataxia. The primary endpoint of the study was the effect of epoetin alfa on peak oxygen uptake (VO2 max) at the cardiopulmonary exercise test. Secondary endpoints were frataxin levels in peripheral blood mononuclear cells, improvement in echocardiography findings, vascular reactivity, neurological progression, upper limb dexterity, safety, and quality of life. Epoetin alfa or placebo (1:1 ratio) was administered subcutaneously at a dose of 1200 IU/Kg of body weight every 12 weeks for 48 weeks. Results: A total of 56 patients were randomized; 27 completed the study in the active treatment group, and 26 completed the study in the placebo group[KG1]. VO2 max was not modified after treatment (0.01 [-0.04 to 0.05]; P=.749), as well as most of the secondary endpoint measures, including frataxin. The 9-hole peg test showed a significant amelioration in the treatment group (-17.24 sec. [-31.5 to -3.0]; P=.018). The treatment was safe and well tolerated. Conclusions: Although results are not in favor of an effect of epoetin alfa in Friedreich ataxia, this is the largest trial testing its effect. It is still possible that epoetin alfa may show some symptomatic effect on upper-limb performance. This study provides class I evidence that erythropoietin does not ameliorate VO2 max in patients with Friedreich ataxia.