September 4, 2008

Plexxikon Initiates Phase I Study of New Drug for Pain and Renal Disease

US-based drug discovery and development company Plexxikon has started a Phase I human clinical trial for PLX5568, a novel kinase inhibitor targeted for the treatment of at least two major indications with unmet medical needs pain as well as polycystic kidney disease.

Dosing has been completed in the first cohort of healthy volunteer subjects in the single ascending dose, double-blind, placebo-controlled trial, which will enroll approximately 30 subjects. This study will be followed by a multiple ascending dose, double-blind, placebo-controlled trial, which will enroll approximately 32 healthy volunteer subjects.

Together, these studies are being conducted to evaluate the safety and tolerability of PLX5568 as well as to gain insight into the pharmacokinetic profile of the drug candidate. Preliminary pharmacokinetic data from the Phase I trial indicate that the exposure in blood achieved with the initial dose is in the target range required to show efficacy with once-a-day capsule dosing.

According to the company, PLX5568 has demonstrated preclinical efficacy in multiple pain models, including neuropathic pain as well as acute and inflammatory pain. In addition, PLX5568 has demonstrated efficacy in multiple preclinical models of polycystic kidney disease.

Peter Hirth, CEO of Plexxikon, said: "PLX5568 represents the fifth investigational new drug from our discovery platform to enter the clinic in four years, and expands our therapeutic portfolio now also to pain and renal disease with this first-in-class agent, underscoring our early development capabilities as well as the productivity and breadth of our discovery platform.

"Additionally, PLX5568 is a highly selective drug candidate and yet another example of Plexxikon's hallmark capability to design very selective kinase inhibitors. Given this capability, we are uniquely positioned to explore kinase drug candidates for the potential treatment of chronic indications where safety is paramount."