Shares of Santa Clara-based XenoPort surged 44 percent Wednesday after the biotechnology company reported encouraging data from a study of its drug candidate for treating a common leg ailment.
The firm’s stock rose $12.70 to $41.56 at the close of trading.
The late-stage study involved 222 patients suffering from restless-leg syndrome, a condition affecting at least 12 million people in the United States, according to the National Institutes of Health.
The ailment, which some patients describe as a burning sensation and others as a feeling of insects crawling under their skin, can disrupt sleep and cause daytime exhaustion.
The study, which ranked the extent of the patients’ symptoms on a 40 point scale, found that XenoPort’s drug – tentatively dubbed XP13512 – reduced the patients’ symptoms by an average of 13.2 points over 12 weeks.
Patients who took a placebo also reported an easing of their symptoms, apparently due to the so-called placebo effect, where untreated patients essentially convince themselves they feel better. Those patients reported an average improvement of nearly 9 points.
While the difference between patients getting the drug and the placebo might not seem much, it was statistically significant and good news for the company, said XenoPort Chief Executive Officer Ronald Barrett.
“It’s a very positive result” that increases the likelihood the drug eventually may win U.S. Food and Drug Administration approval for commercial sale, Barrett said.
It also could bode well for XenoPort’s bottom line.
The company, which has no drugs on the market and has not been profitable since going public in June 2005, has lucrative deals with Astellas Pharma of Japan and GlaxoSmithKline of London to co-develop the drug.
Barrett said his company already has received $110 million under those deals and could receive up to $615 million more – not counting royalty payments from sales – if the drug shows further promise.
In addition to XP13512, XenoPort is developing treatments for such ailments as migraines, nausea, Parkinson’s disease and spasticity.
XenoPort was incorporated in 1999 and has about 150 employees.
Contact Steve Johnson at sjohnson@mercurynews.com or (408) 920-5043.