Phase III randomized trial of gabapentin in patients with amyotrophic lateral sclerosis

Background: Preclinical and clinical studies of gabapentin in patients with ALS led the authors to undertake a phase III randomized clinical trial. Me thods: Patients were randomly assigned, in a double-blinded fashion, to rec eive oral gabapentin 3,600 mg or placebo daily for 9 months. The primary ou tcome measure was the average rate of decline in isometric arm muscle stren gth for those with two or more evaluations. Results: Two hundred four patie nts enrolled, 196 had two or more evaluations, and 128 patients completed t he study. The mean rate of decline of the arm muscle strength was not signi ficantly different between the groups. Moreover, there was no beneficial ef fect upon the rate of decline of other secondary measures (vital capacity, survival, ALS functional rating scale, timed walking) nor was there any sym ptomatic benefit. In fact, analysis of the combined data from the phase II and III trials revealed a significantly more rapid decline of forced vital capacity in patients treated with gabapentin. Conclusion: These data provid e no evidence of a beneficial effect of gabapentin on disease progression o r symptoms in patients with ALS.