DM-1796 (Gabapentin GR - PHN)

DM-1796 is an investigational formulation of gabapentin, an FDA-approved immediate release pharmaceutical for the treatment of partial epilepsy and management of postherpetic neuralgia (PHN). Depomed is currently developing DM-1796, an AcuForm™-enhanced formulation administered once- or twice-daily for the treatment PHN.

PHN is a persistent neuropathic pain condition. It is caused by nerve damage after a shingles, or herpes zoster, viral infection and afflicts approximately one in five patients diagnosed with shingles (~ 150,000 individuals) in the United States. The incidence of PHN increases in elderly patients, with 75 percent of those over 70 years old who have shingles, developing PHN. The pain associated with PHN reportedly can be so severe that patients are unable to resume normal activities for months.

Leveraging AcuForm Technology

Gabapentin available on the market today is formulated for immediate release (IR). Upon ingestion, the entire administered dose is ‘dumped’ into the stomach allowing for it to be rapidly absorbed into the blood. This rapid absorption leads to peak concentrations of the active ingredient, which gives rise to commonly experienced side effects including dizziness and daytime sleepiness. Patients taking immediate release formulations of gabapentin frequently need to take it four to five times a day to effectively manage their pain.

Formulated with AcuForm delivery technology, DM-1796 is designed for targeted, controlled release to the upper GI tract over a six to eight hour period. This extended release allows for the drug to be gradually absorbed into the blood, reducing the likelihood of peak concentrations and potentially resulting in fewer side effects than seen with immediate release formulations. Greater treatment tolerability and a more convenient dosing regimen made possible with AcuForm could potentially translate into greater patient compliance and ultimately better pain management.

Clinical Results

On October 5, 2009, we announced top-line results from a Phase 3 clinical trial demonstrating DM-1796 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.

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).

Please visit other pages on this section of the website to learn about DM-1796 in clinical development for the treatment of diabetic peripheral neuropathy and menopausal hot flashes. 

The data referenced in the preceding paragraphs represent the most recently announced data pertaining to this program. For data from earlier trials, please refer to the press release section of this website.