Most people wouldn’t think that a case of chicken pox could cause chronic pain, but many people across the U.S. feel the effects of this common childhood disease years after the red spots have disappeared. When the initial infection heals, some of the virus remains dormant in the body. Years later, it may reawaken and cause shingles, a painful skin condition resulting in red patches and blisters. Xenoport of Santa Clara, Calif., recently announced positive mid-stage trial data for a drug to treat chronic pain related to shingles.
Post-herpetic neuralgia is a complication of shingles. Although the skin typically heals within a month, some patients continue to feel nerve pain long after the infection goes away. This pain, called post-herpetic neuralgia, usually affects people over 50. Post-herpetic neuralgia can lead to severe discomfort and disability. It is usually treated with antidepressants, anticonvulsants, steroids, painkillers, or electrical nerve stimulation. About 10 to 20 percent of sufferers experience pain for a year or more. For some, the pain never goes away.
Xenoport announced Thursday that its neuropathic pain drug, XP13512 or GSK1838262, met its primary goal in a Phase IIb clinical trial. The medication led to a significant reduction in pain compared to a placebo. Xenoport is partnered with GlaxoSmithKline (GSK) to develop the drug. Shares in Xenoport rose 29 percent following the announcement. This is good news for Xenoport: The Santa Clara, Calif.-based company experienced a setback in April when its experimental treatment for peripheral diabetic neuropathy failed a mid-stage clinical trial. Xenoport had also partnered with GSK for that endeavor.
Algos Therapeutics is another company focused on developing a treatment for post-herpetic neuralgia. The company works to design and execute programs for pain research.