UPDATE 1-Cephalon sleep drug wins fast review for jet lag

* FDA decision on new Nuvigil use expected Dec. 29

* Shares rise 1.3 percent

NEW YORK, Sept 24 (Reuters) - U.S. regulators will review Cephalon Inc's CEPH.O Nuvigil sleep disorder drug on a priority basis for an additional use of treating excessive sleepiness tied to jet lag, the drugmaker said on Thursday.

The U.S. Food and Drug Administration is expected to decide by Dec. 29 whether to approve Nuvigil for the use.

Specifically, the FDA is reviewing Nuvigil as a treatment for "improving wakefulness in patients with excessive sleepiness associated with jet lag disorder due to eastbound travel," Cephalon said.

There are currently no FDA-approved treatments for "jet lag disorder," according to Cephalon.

With priority review status, the FDA will make its decision on whether to approve the drug within six months, rather than the usual 10- to 12-month review period. The agency grants priority review to products that are considered to be potentially significant therapeutic advancements over existing therapies.

Cephalon launched Nuvigil, a follow-up to its Provigil sleep drug, in June in the United States.

Shares of Cephalon rose 1.3 percent to $59.51 in premarket trading on Nasdaq. (Reporting by Lewis Krauskopf, editing by Dave Zimmerman)