Non opium pain drug tezampanel can treat acute migraine, says Raptor

Tezampanel, a non opium based pain killer by Raptor Pharmaceutical Corporation, has been found effective in dealing with acute migraine and other neuropathic pain. 

NGX426 is a prodrug of tezampanel is an orally administered non-opioid, AMPA/kainate antagonist.

When given subcutaneously and intravenously tezampanel demonstrated statistically significant analgesic effect in five Phase II trials.

Tezampanel was studied in acute migraine, nociceptive pain and neuropathic pain models.

Tezampanel phase II programme was a single center, double-blind, randomized study.

The prmiary objective of tezampanel phase II programme was to demonstrate that the orally administered prodrug NGX426, maintains the analgesic effect previously shown for the active moiety tezampanel.

Using a cross-over design, a total of 18 study subjects received single doses of 90 mg of NGX426, 150 mg of NGX426 or placebo in each of three treatment periods.

Pain was induced by injecting 250 ug of capsaicin between layers of skin in the forearm at 30 minutes and 120 minutes after dosing.

“Tezampanel and its oral prodrug NGX426 are the first glutamate receptor antagonists to be tested in human pain trials with combined binding activity at the AMPA and kainite receptor subtypes. In particular, this novel, non-opioid mechanism of action is interesting in the context of neuropathic pain where multiple therapies are typically used to manage the condition,” stated Raptor’s Chief Medical Officer, Patrice Rioux.

Raptor is hopeful that once released tezampanel data will further demonstrate the potential value of NGX426 in the treatment of migraine and chronic pain.

Raptor also plans to study tezampanel and NGX426 in various other categories of pain.

Tezampanel is the first AMPA/kainate antagonist to be studied in a clinical trial for acute migraine and represents a novel, non-opioid, non-vascular, and non-serotonergic approach to treating multiple pain conditions including migraine.

Tezampanel is an antagonist of a subgroup of glutamate receptors referred to as AMPA and kainate. These receptors are found in areas of the central and peripheral nervous system that are important for the transmission of pain.

During a migraine attack, levels of glutamate increase and activate these receptors, facilitating the transmission of pain impulses. Tezampanel, by blocking the binding of glutamate to these receptors, is believed to inhibit the transmission of pain signals that lead to migraine headaches.

Tezampanel was originally developed by Eli Lilly.

In April 2003, TorreyPines acquired worldwide rights and all intellectual property for product candidates NGX424 and NGX426 from Eli Lilly and Co. In October 2008, the company initiated a Phase I multiple dose trial of NGX426 in healthy adults.

Raptor Pharmaceutical Corp merged with troubled TorreyPines Therapeutics Inc. in July this year gaining the rights of NGX426.

What is migraine?

Migraine is a debilitating neurological condition characterized by an intense and disabling episodic headache.

In addition to headache pain, migraine attacks are frequently accompanied by photophobia, phonophobia, nausea and vomiting.

More than 50 percent of migraine sufferers endure from one to four migraine attacks per month.

Although once thought to be primarily caused by vascular changes in the brain, some researchers now consider migraine a neurological disorder.

An estimated 30 million people in the US suffer from migraines, according to the National Headache Foundation.

Raptor Pharmaceutical Corp specializes in improving existing therapeutics through the application of specialized drug targeting platforms and formulation expertise.

Raptor currently has product candidates in clinical development designed to potentially treat nephropathic cystinosis, non-alcoholic steatohepatitis (NASH), Huntington’s Disease (HD), aldehyde dehydrogenase (ALDH2) deficiency, and a non-opioid solution designed to potentially treat chronic pain.

Raptor’s preclinical programs are based upon bioengineered novel drug candidates and drug-targeting platforms derived from the human receptor-associated protein (RAP) and related proteins that are designed to target cancer, neurodegenerative disorders and infectious diseases.