DefinedHealth

Ginger S. Johnson, PhD.

Pharma is turning its sights to the market for neuropathic pain. Driven by the success of Neurontin, originally indicated as an antiepileptic, companies are venturing into what is potentially an enormous and largely untapped market (estimates of over 12 million people affected in the US). The journey will not be for the timid; neuropathic pain is complex, encompassing a wide range of pain syndromes of diverse etiologies that are poorly understood. Recently launched agents have been specifically developed for distinct types of neuropathic pain Pfizer’s Lyrica (pregabalin), for postherpetic neuralgia and diabetic peripheral neuropathy, and Lilly’s Cymbalta (duloxetine), for diabetic peripheral neuropathy. Whether or not these agents address a mechanism common across the gamut of neuropathic pain types is yet to be determined. Given the unmet need, however, physicians will likely try these agents in their neuropathic pain patients, regardless of the underlying condition, thereby contributing to their blockbuster revenue projections.

Biotech, specialty companies and additional big pharma are quickly following in the path of these trail blazers. The pipeline, while active, is largely void of novelty. Instead it is loaded with established mechanisms / classes seeking new indications, mostly antiepileptics (e.g.,Tegretol, Novartis; Lamictal, GSK; Keppra, UCB); reformulations of existing products (e.g., Gabapentin XR, Depomed) and topical anesthetics (e.g., transdermal lidocaine, Endo; topical capsaicins, NeurogesX and Winston Labs; topical amitriptyline / ketamine combination, Epicept). Pfizer and Lilly are seeking an additional fibromyalgia indication for their neuropathic pain agents, while Forest struggles through a third pivotal Phase III fibromyalgia study with milnacipran, a dual acting norepinephrine / serotonin reuptake inhibitor.