News Feature | December 22, 2014

Pfizer Posts Positive Phase 3 Data For Pregabalin In PHN

By Estel Grace Masangkay

Pfizer reported top-line results from the Phase 3 study assessing its drug pregabalin controlled-release (CR) formulation as treatment for adult patients with postherpetic neuralgia (PHN).

Postherpetic neuralgia is a form of peripheral neuropathic pain resulting from nerve damage. Symptoms of the condition include electric shock-like pain or a continued burning sensation.

The double blind, placebo controlled, randomized Phase 3 study investigated the safety and efficacy of Lyrica CR versus placebo in treating PHN-associated pain in patients who demonstrated an initial response to single-blind pregabalin. The study was structured in four stages: baseline, single-blind treatment, double-blind treatment, and a 1-week double blind taper.

The late stage trial's primary endpoint was defined as the time to loss of therapeutic response (LTR) in pain reduction. Results show that Lyrica demonstrated statistically significant positive effect compared to placebo. Roughly 14 percent of patients who took Lyrica versus 30.7 percent of those in placebo experienced pain response relative to the baseline mean pain or withdrawal due to lack of efficacy or adverse events. Pfizer said the difference between the two treatment arms were significant.

Pfizer said it will submit full results of the study for publication when analyses are completed.

Pregabalin, marketed as Lyrica, is authorized for a range of indications in 120 countries and territories worldwide. Indications for the drug include: neuropathic pain linked with diabetic peripheral neuropathy; post-herpetic neuralgia (which is more commonly known as pain that occurs after shingles); neuropathic pain related to spinal cord injury; fibromyalgia; and partial onset seizures in adults with epilepsy undergoing treatment. Pfizer is currently developing Lyrica for certain pain conditions.

Earlier this year, Pfizer reported top-line results from its China study for Lyrica in patients with PHN and painful diabetic peripheral neuropathy (pDPN). However, Bloomberg reported that Pfizer's best selling drug failed to help people with common back pain compared to placebo in a recent study.