TORREYPINES COMPLETES SAFETY STUDY OF PAIN DRUG

TorreyPines Therapeutics has reported findings from a Phase I clinical trial for NGX426, a novel oral therapy intended for the treatment of acute migraine and chronic pain conditions, such as neuropathic pain. The compound, an oral prodrug of the company's lead compound, tezampanel, was found to be well-tolerated and rapidly converted to tezampanel at all doses tested.

This Phase I study enrolled 30 healthy adult male volunteers at one center in the U.S. The double-blind, placebo-controlled, ascending-dose, sequential-cohort study was designed to evaluate the safety, tolerability and pharmacokinetics of NGX426, as well as to determine the rate and extent of conversion of the prodrug, NGX426, to the active drug, tezampanel. In this study, volunteers were randomized to receive single oral doses of 10, 20 and 30 mg of NGX426 or placebo. There were no dose-limiting or dose-related increases in adverse events. Reported adverse events were generally mild in intensity and similar to those previously reported for tezampanel. In addition, there were no drug-related laboratory abnormalities or clinically important changes in cardiovascular parameters. Furthermore, pharmacokinetic analyses suggest rapid conversion of NGX426 to tezampanel.

As AMPA/kainite receptor antagonists, NGX426 and tezampanel offer a unique mechanism of analgesia that is non-narcotic and non-vascular in approach. As such, both compounds may effectively relieve severe and persistent pain without imparting the risks and side effects associated with currently available treatments. Importantly, neither compound shows any clinically relevant effects on the cardiovascular system in animal models or in man, nor demonstrates interaction with serotonin receptors, so these compounds may offer an effective alternative for migraine sufferers for whom triptans, the current treatment standard, are contraindicated. Tezampanel, delivered subcutaneously, is currently in a Phase IIb clinical trial for acute migraine. NGX426 will be studied initially for acute migraine and then for chronic pain conditions such as neuropathic pain.