An Efficacy and Safety Study of Carisbamate in the Treatment of Nerve Pain in Diabetics
Condition: Diabetic Neuropathies
MeSH terms: Diabetic Neuropathies
Study type: Interventional
Phase: Phase 2

Summary: 
      The purpose of this study is to evaluate the safety, tolerability, and efficacy of
      carisbamate (800 and 1200 mg/day) in patients with diabetic neuropathic pain.
    

Detailed description: 
      This is a randomized (study medication assigned by chance), double-blind (neither the
      investigator or the patient knows the name of the study assigned drug), placebo- and
      active-controlled, parallel-group, multicenter study, with an optional extension phase, in
      patients with diabetic peripheral neuropathy (DPN), or nerve pain in their lower extremities
      resulting from diabetes. The study population includes men and women between 18 and 75 years
      of age who have chronic neuropathic pain associated with diabetic neuropathy. Up to 440
      subjects will be enrolled and randomly assigned (like flipping a coin) in a 1:1:1:1 ratio to
      treatment with carisbamate 800 milligrams per day (mg/d), carisbamate 1,200 mg/d, pregabalin
      300 mg/d, or placebo. The double-blind treatment will be administered orally, in a
      twice-daily regimen, with or without food, over a period of 15 weeks. The study will consist
      of a pretreatment phase, including a screening, washout, and baseline period; a double-blind
      treatment phase, with a titration and a fixed-dosage period; an optional blinded extension
      phase (with carisbamate 400 to 1,200 mg/d or pregabalin 150 to 300 mg/d); and a posttreatment
      phase (including a follow-up visit and telephone contact). The duration of the study
      (excluding the pretreatment phase) is approximately 58 weeks for patients who decide to enter
      the extension phase and approximately 19 weeks for the other patients. The pretreatment phase
      will last up to 28 days, including a screening visit up to 28 days before the planned first
      dose of study drug, a washout of up to 7 days for subjects who need to discontinue
      medications, and a baseline period of at least 7 days to determine daily average DPN scores
      for entry into the study. The double-blind treatment phase will include a titration period of
      3 weeks to determine the dosage, and a fixed-dosage period for the next 12 weeks. All
      patients who complete the double-blind treatment phase will be offered the option to enter
      the blinded extension phase for an additional 37 weeks, in which patients previously treated
      with carisbamate or placebo will receive carisbamate at their individual dosage at the end of
      the double-blind treatment period, and patients previously treated with pregabalin will
      receive pregabalin at their individual dosage at the end of the double-blind treatment
      period. During the double-blind and extension phases, patients will have daily assessments of
      their pain, using the 11-point DPN pain rating scale; and how much their pain interferes with
      their sleep, using an 11-point Sleep Interference rating scale. In addition, specific scales
      will be used at visits (every week for the first 4 weeks, every 4 weeks through the end of
      the double-blind treatment phase, every 11 to 12 weeks in the extension phase) to assess
      pain, overall health quality, the effects of pain on daytime sleepiness, and the effects of
      pain on work, activities, and health care utilization. Patients will remain blinded to the
      drug assignment during the extension phase. The posttreatment phase will include a follow-up
      visit with 7 to 14 days after the final visit of the double-blind treatment phase (for
      patients who do not participate in the extension phase) or the extension phase. In addition,
      the investigator staff will call patients 30 to 33 days after the last dose of study drug, to
      ask about any adverse events. Patients will take two oral capsules each day, either
      carisbamate (200 or 400 mg), matching pregabalin (75 or 150 mg), or matching placebo.
    

Intervention name(s): Pregabalin 300 mg/d; Carisbamate 800 mg/d; Carisbamate 1,200 mg/d; Placebo
Intervention type(s): Drug; Drug; Drug; Drug
Intervention description(s): 75 mg/d twice daily for Week 1, followed by 150 mg twice daily for the remainder; 200 mg/d twice daily, titrated up to 400 mg twice daily, as tolerated, by Week 3; 200 mg/d twice daily, titrated up to 600 mg twice daily, as tolerated, by Week 3; Placebo capsules twice daily
Intervention MeSH terms: Pregabalin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Diabetic neuropathies; Diabetic neuropathy, painful; Carisbamate; Neurotherapeutic agents