Cephalon Receives Complete Response Letter for NUVIGIL for the Treatment of Excessive Sleepiness Associated with Jet Lag Disorder

Frazer, Pa. - December 27, 2010

Cephalon, Inc. (Nasdaq: CEPH) today announced that the company received a second Complete Response Letter from the U.S. Food and Drug Administration (FDA) for the supplemental new drug application (sNDA) for NUVIGIL(R) (armodafinil) Tablets [C-IV] for the treatment of patients with excessive sleepiness associated with jet lag disorder resulting from eastbound travel.  In its letter to the company, the FDA reiterated its previously stated concerns regarding the NUVIGIL sNDA. 

"Cephalon believes we met the agreed upon safety and efficacy endpoints in the NUVIGIL sNDA clinical study conducted under a Special Protocol
Assessment.   However, following several conversations with the agency, and
given this second complete response letter, the company believes that further communications with the FDA will not result in an approval of this application," said Dr. Lesley Russell, Chief Medical Officer at Cephalon.
"As a result, the company is no longer pursuing this indication."

About NUVIGIL

NUVIGIL is indicated to improve wakefulness in patients with excessive sleepiness associated with treated obstructive sleep apnea (OSA), shift work disorder (SWD), or narcolepsy.  In patients with OSA, NUVIGIL is used along with airway treatments for this condition.  The NUVIGIL (armodafinil) label includes a bolded warning for serious or life-threatening rash, including Stevens-Johnson Syndrome, requiring hospitalization and discontinuation of treatment, that has been reported in adults in association with the use of modafinil and armodafinil and in children in association with the use of modafinil, a racemic mixture of S and R modafinil (the latter is armodafinil, the active ingredient in NUVIGIL).  NUVIGIL is not approved for use in pediatric patients for any indication.

The most common adverse events in controlled clinical trials (five percent or greater) in labeled indications were headache, nausea, dizziness, and insomnia.  Full prescribing information for NUVIGIL is available at www.nuvigil.com.

About Cephalon, Inc.

Cephalon is a global biopharmaceutical company dedicated to discovering, developing and bringing to market medications to improve the quality of life of individuals around the world.  Since its inception in 1987, Cephalon has brought first-in-class and best-in-class medicines to patients in several therapeutic areas.  Cephalon has the distinction of being one of the world's fastest-growing biopharmaceutical companies, now among the Fortune 1000 and a member of the S&P 500 Index, employing approximately 4,000 people worldwide.  The company sells numerous branded and generic products around the world.  In total, Cephalon sells more than 150 products in nearly 100 countries.  More information on Cephalon and its products is available at www.cephalon.com <http://www.cephalon.com/> .