SANTA CLARA, Calif. (AP) -- Drug developer XenoPort Inc. said Friday that there's a shortage of its restless leg syndrome treatment Horizant.
The company said it's received word from patients unable to fill their Horizant prescriptions. XenoPort hopes that a new stock of Horizant will be in pharmacies in June, but the timing is uncertain.
A company representative said British drugmaker GlaxoSmithKline, which is responsible for making the drug, has run out of its supply, but some distributors still have it stock.
Glaxo is working with its contract manufacturer to resolve problems, XenoPort said. Glaxo is supplying XenoPort with Horizant until Oct. 30 under an agreement between the companies. XenoPort is preparing to take over sales of the drug May 1.
Horizant was launched in 2011. Last year, the Food and Drug Administration also approved Horizant as a treatment for nerve pain that follows shingles, a viral infection related to chicken pox. XenoPort also is developing potential treatments for Parkinson's disease, multiple sclerosis and psoriasis.
Shares of XenoPort, based in Santa Clara, Calif., fell 2.5 percent, or 18 cents, to $7.08 in morning trading.