Depomed, Inc announced top-line results from a phase-3 clinical trial demonstrating DM-1796 (also referred to as gabapentin ER) achieved a statistically significant reduction in pain associated with postherpetic neuralgia (PHN) versus placebo using the baseline observation carried forward (BOCF) method required by FDA. The primary endpoint measured pain scores from baseline to the end of a ten-week treatment period using the numerical Likert pain scale.

DM-1796 is an investigational extended release, once-daily tablet formulation of gabapentin for the treatment of PHN. Depomed has licensed DM-1796 to Solvay Pharmaceuticals, Inc in the United States, Canada and Mexico for the treatment of pain.

"This study demonstrates the effectiveness of our proprietary drug delivery technology in producing meaningful clinical benefits for PHN patients. We look forward to working with our strong and committed partner, Solvay Pharmaceuticals, through the regulatory process and making DM-1796 a commercial success," said Carl A Pelzel, president and chief executive officer of Depomed.

"The study results represent another step forward in the potential for DM-1796 to be an important new option for patients with postherpetic neuralgia who often struggle to find effective pain relief treatments," noted Dr Michael Sweeney, Depomed's vice president, Research and Development. "Gabapentin has proven efficacy, and the study data suggest that the new extended-release formulation may offer a favourable side effect profile and added convenience," Dr Sweeney added.

Conducted by Depomed, the randomized, double-blind, placebo-controlled study involved 452 PHN patients. Patients in the study were randomized into two treatment arms: placebo or 1800 mg of DM-1796 dosed once-daily. Secondary objectives included an assessment of changes from baseline in sleep interference, and additional patient and clinician assessments of pain and quality of life. In the study, DM-1796 was well tolerated. The most common side effects observed in patients receiving DM-1796 were dizziness (11.3% compared to 1.7% for placebo) and somnolence (5.4% compared to 3.0% for placebo).

Full study results are being analyzed at this time and will be submitted for presentation at a future medical meeting. A New Drug Application (NDA) for DM-1796 for the treatment of PHN is expected to be submitted to the US Food and Drug Administration (FDA) by the end of first quarter 2010.

Postherpetic neuralgia (PHN), or pain after shingles, is a persistent neuropathic pain condition.

DM-1796 is currently being studied as a once-daily treatment for postherpetic neuralgia in 300 and 600 mg strengths.

Depomed is a specialty pharmaceutical company with two product candidates in Phase 3 clinical development, two approved products on the market and other product candidates in its early stage pipeline.