ORIGINAL ARTICLE Efficacy and Safety of Carisbamate in Patients with Diabetic Neuropathy or Postherpetic Neuralgia: Results from 3 Randomized, Double- Blind Placebo-Controlled Trials Timothy Smith, MD*; Allitia DiBernardo, MD † ; Yingqi Shi, PhD † ; Mike J. Todd, MS † ; H. Robert Brashear, MD ‡ ; Lisa M. Ford, MD † *Mercy Health Research, Center for Innovative Care, Mercy Health, St. Louis, Missouri ; † Janssen Research & Development, LLC, Raritan, New Jersey; ‡ Janssen Alzheimer Immunotherapy, South San Francisco, California, U.S.A. & Abstract: The results of 3 proof-of-concept studies to evaluate carisbamate’s efficacy and safety in treating neuro- pathic pain are presented. In studies 1 (postherpetic neural- gia, n = 91) and 2 (diabetic neuropathy, n = 137), patients received carisbamate 400 mg/day or placebo for 4 weeks and then crossed over to the other treatment for 4 weeks. In study 3 (diabetic neuropathy, higher carisbamate doses), patients (n = 386) were randomized (1:1:1:1) to receive either carisbamate 800 mg/day, 1200 mg/day, pregabalin 300 mg/ day or placebo for 15 weeks. Primary efficacy end point was the mean of the last 7 average daily pain scores obtained on days the study drug was taken, for all 3 studies. Least square mean (95% CI) differences between carisbamate and placebo groups on the primary end point were as follows: study 1: 0.512 (1.32, 0.29) carisbamate 400 mg/day; study 2: 0.307 (0.94, 0.33) carisbamate 400 mg/day; and study 3: 0.51 (1.10, 0.08), carisbamate 800 mg/day; 0.55 (1.13, 0.04), carisbamate 1200 mg/day; and 0.43 (1.01, 0.15), pregab- alin 300 mg/day. Neither carisbamate (all 3 studies) nor pregabalin (study 3) significantly differed from placebo, although multiple secondary end points showed significant improvement in efficacy with carisbamate in studies 1 and 2. Dizziness was the only treatment-emergent adverse event occurring at  10% difference in carisbamate groups versus placebo (study 1: 12% vs. 1%; study 3: 14% vs. 4%; study 2: 1% vs. 2%). Carisbamate, although well tolerated, did not demonstrate efficacy in neuropathic pain across these stud- ies, nor did the active comparator pregabalin (study 3). & Key Words: carisbamate, diabetic peripheral neuropathy, postherpetic neuralgia, pregabalin Address correspondence and reprint requests to: Timothy Smith, MD, Vice President of Research, Mercy Health Research, Center for Innovative Care, Mercy Health System, St. Louis, MO 63017, U.S.A. E-mail: Timothy. Smith@mercy.net. Disclosures: This study was funded by Janssen Research & Develop- ment, LLC, Raritan, N.J., U.S.A. The sponsor also provided a formal review of this article. Dr. Smith was the principal investigator of the trial NCT00870454, and the Dr. Smith’s employer received compensation from Janssen Research & Development for study conduction. Drs Ford and Shi are employees of Janssen Research & Development, LLC. Dr DiBernardo was an employee of Janssen Research & Development, LLC, at the time these studies were conducted and completed. Dr. Brashear is an employee of Janssen Alzheimer Immunotherapy, L.L.C, San Francisco, California, and was employed by Janssen Research & Development, LLC, during the time of these studies. Mr. Todd is a consultant to Janssen Research & Development, LLC, and has also received fees from other companies. Specifically, Drs Smith, DiBernardo, Shi, Brashear, and Ford contributed to study design, data interpretation, and analysis. Dr. Shi and Mr. Todd performed the statistical analyses and also provided interpretation of the data. All authors met ICMJE criteria, and all those who fulfilled those criteria are listed as authors. All authors had access to the study data, provided direction and comments on the article, made the final decision about where to publish these data, and approved submission to the journal. Submitted: March 04, 2013; Revision accepted: April 12, 2013 DOI. 10.1111/papr.12080 © 2013 World Institute of Pain, 1530-7085/13/$15.00 Pain Practice, Volume , Issue , 2013 –