Pfizer nerve drug may see setbacks

Lyrica (pregabalin capsules) have received FDA approval for the management of neuropathic pain associated with diabetic peripheral neuropathy (DPN) and postherpetic neuralgia (PHN). Lyrica is the first FDA-approved treatment for both of these neuropathic pain states, which are distinctly different from arthritis or musculoskeletal pain.

The pain of DPN is often described as burning, tingling, sharp, stabbing, or pins and needles in the feet, legs, hands or arms, while PHN is a complication of shingles, a painful outbreak of rash or blisters on the skin caused by a reactivation of the same virus that causes chicken pox.

The efficacy of Lyrica was established in six double-blind, placebo-controlled trials, three involving patients with DPN and three involving patients with PHN. Lyrica provided rapid and clinically meaningful pain reduction in a significant portion of patients, with pain relief beginning as early as the first week of treatment in some patients.

The safety of Lyrica was also established in over 9,000 patients. In all clinical trials, adverse events were mild to moderate and the discontinuation rate due to side effects was low.

Pfizer expects Lyrica to be classified as a controlled substance in a category with lower potential for misuse or abuse relative to controlled substances in other categories. As a controlled substance, Lyrica will be more difficult to market and distribute, and thus the classification could prove a setback for Pfizer according to reports.

Lyrica is currently under review by the FDA for the adjunctive treatment of partial seizures in adults. In July 2004, Pfizer received European Commission approval to market Lyrica in EU member states for the treatment of peripheral neuropathic pain and as adjunctive therapy for partial seizures.