TorreyPines Therapeutics has initiated a phase I clinical trial for its first-in-class compound, which claims to offer a non-opioid, non-vascular approach to the management of severe pain.
An AMPA/kainate (AK) receptor antagonist, NGX424 selectively block transmission of pain signals mediated through the activation of glutamate receptors.
These receptors play a critical role in the development of central sensitisation phenomena, a key component of many pain syndromes, including migraine and persistent pain states such as chronic neuropathic pain.
Because they do not block opioid receptors, constrict blood vessels or interact with systems external to the central nervous system at dosages that are therapeutically relevant, the safety profile of AK antagonists may offer important advantages over existing drugs.
The Phase I trial with NGX424 will enroll approximately 90 healthy male volunteers at one centre in the US.
The single, ascending, fixed-dose, study will evaluate the local and systemic tolerability, safety and pharmacokinetics of the drug, as well as the maximum tolerated dose of a subcutaneous formulation.
"We're pleased to initiate clinical trials with NGX424, which could offer a better safety profile and more effective pain relief to sufferers worldwide," said Neil Kurtz, chief executive officer at TorreyPines.
"We believe NGX424, and its follow-on compound NGX426, an oral prodrug, may effectively relieve pain through a novel mechanism, without having a negative impact on the cardiovascular system or imparting side effects and risks that may be associated with pain relief medications," he added.
TorreyPines licensed NGX424 and its oral prodrug NGX426 from Eli Lilly in 2003. In addition to a subcutaneous route of administration, the company intends to continue development of the intravenous formulation, as well as develop intrathecal and epidural formulations.
These multiple dosing forms permit development across a range of indications including severe migraine, epilepsy, neuropathic pain, spinal cord injury and other intractable pain states.
"With NGX424 and NGX426, we have the potential to address unmet needs in virtually every segment of the pain market," said Dr. Kurtz.
The European and US neuropathic pain markets are currently worth $2.5 billion (€2.1 billion) combined.
While most drugs currently used are not primarily indicated for neuropathic pain, the blockbuster status of Neurontin in this indication has focused the attention of several pharmaceutical giants on this potentially lucrative market.
As such, Datamonitor expects the market to be worth over $4 billion by 2007.