FDA Extends PDUFA Date for VIVITREX(R) to December 30, 2005; Cephalon and Alkermes Continue to Anticipate VIVITREX Launch in First Half of 2006

Cephalon, Inc. (Nasdaq: CEPH) and Alkermes, Inc.(Nasdaq: ALKS) announced today that they have received notificationfrom the United States Food and Drug Administration (FDA) that theagency has extended the action date to December 30, 2005 for itspriority review of the New Drug Application (NDA) for VIVITREX(R)(naltrexone long-acting injection) for the treatment of alcoholdependence. The original action date under the Prescription Drug UserFee Act (PDUFA) for the VIVITREX NDA was September 30, 2005. Thecompanies continue to anticipate the launch of VIVITREX in the firsthalf of 2006.

The extension is a result of the FDA classifying a recent responseby Alkermes as a major amendment to the NDA, which permits the FDA toextend the action date by 90 days under PDUFA regulations.

"We will continue to work closely with the FDA to assist them inthe completion of the review of the application in a timely manner,"stated Richard Pops, CEO of Alkermes. "This extension does not affectour plans for the timing of the commercial launch of VIVITREX."

"We have made great progress in developing commercial launch plansfor VIVITREX and remain on schedule for a product launch in the firsthalf of 2006," said Frank Baldino, Jr., Ph.D., Chairman and CEO ofCephalon.

In June 2005, Cephalon and Alkermes entered into an agreement todevelop and commercialize VIVITREX in the United States for thetreatment of alcohol dependence.

About Cephalon, Inc.

Founded in 1987, Cephalon, Inc. is an internationalbiopharmaceutical company dedicated to the discovery, development andmarketing of innovative products to treat sleep and neurologicaldisorders, cancer and pain. Cephalon currently employs approximately2,300 people in the United States and Europe. U.S. sites include thecompany's headquarters in Frazer, Pennsylvania, and offices,laboratories or manufacturing facilities in West Chester,Pennsylvania, Salt Lake City, Utah, and suburban Minneapolis,Minnesota. Cephalon's European headquarters are located inMaisons-Alfort, France and other European offices are located inGuildford, England, and Martinsried, Germany.

The company currently markets four proprietary products in theUnited States: PROVIGIL(R) (modafinil) (C-IV), GABITRIL(R) (tiagabinehydrochloride), ACTIQ(R) (oral transmucosal fentanyl citrate) (C-II)and TRISENOX(R) (arsenic trioxide) injection, and more than 20products internationally. Full prescribing information on its U.S.products is available at www.cephalon.com or by calling1-800-896-5855.

About Alkermes, Inc.

Alkermes, Inc. is a pharmaceutical company that develops productsbased on sophisticated drug delivery technologies to enhancetherapeutic outcomes in major diseases. The Company's lead commercialproduct, RISPERDAL CONSTA(R) ((risperidone) long-acting injection), isthe first and only long-acting atypical antipsychotic medicationapproved for use in schizophrenia, and is marketed worldwide byJanssen-Cilag (Janssen), a wholly owned subsidiary of Johnson &Johnson. The Company's lead proprietary product candidate, VIVITREX(R)(naltrexone long-acting injection) is being developed as aonce-monthly injection for the treatment of alcohol dependence. TheCompany has a pipeline of extended-release injectable products andpulmonary drug products based on its proprietary technology andexpertise. Alkermes' product development strategy is twofold: theCompany partners its proprietary technology systems and drug deliveryexpertise with several of the world's finest pharmaceutical companiesand it also develops novel, proprietary drug candidates for its ownaccount. The Company's headquarters are in Cambridge, Massachusetts,and it operates research and manufacturing facilities in Massachusettsand Ohio.

Certain statements set forth above may constitute forward-lookingstatements within the meaning of the Private Securities LitigationReform Act of 1995, including, but not limited to, statementsconcerning regulatory approval for, and the launch and subsequentsuccessful commercialization of VIVITREX. Although both Cephalon andAlkermes believe that such statements are based on reasonableassumptions within the bounds of their respective knowledge, theforward-looking statements are neither promises nor guarantees, andboth the Alkermes and Cephalon businesses are subject to significantrisk and uncertainties. As such, there can be no assurance that eitheror both of Cephalon's or Alkermes' actual results will not differmaterially from their respective expectations. Such expectations aresubject to risks, including, among others whether Alkermes cansuccessfully scale up and manufacture VIVITREX at a commercial scale;whether VIVITREX will ultimately receive marketing approval from FDA,and, if approved, whether it will be launched and commercializedsuccessfully by Alkermes and Cephalon; the outcome of clinical andpreclinical work Alkermes and its partners are pursuing, including theresults of clinical trials; decisions by the FDA regarding VIVITREX,which may be based on interpretations of data that differ fromAlkermes' interpretations; and whether VIVITREX in commercial use, mayhave unintended side effects, adverse reactions or incidents of misusethat could cause the FDA or other health authorities to require postapproval studies or require removal of the product from the market.For further information with respect to specific risks, uncertaintiesand factors that could cause actual results to differ fromexpectations, reference is made to the reports on Forms 8-K, 10-Q and10-K that Cephalon and Alkermes each filed with the Securities andExchange Commission under the Securities Exchange Act of 1934, asamended. The forward-looking statements made in this release are madeonly as of the date hereof and both Cephalon and Alkermes disclaim anyintention or responsibility for updating such statements, except asmay be required by law.