Cephalon Comments On Study Of Its Leukemia Treatment Led By National Cancer Institute Cooperative Group

Cephalon, Inc. (Nasdaq: CEPH) commented on the announcement today by the National Cancer Institute (NCI) and one of its Cooperative Clinical Trials Groups, the Cancer and Leukemia Group B (CALGB), regarding event-free and overall survival results from a clinical trial using TRISENOX(R) (arsenic trioxide) injection in newly diagnosed patients with acute promyelocytic leukemia (APL). After reviewing the results from more than 500 patients in the study, a data safety monitoring board notified the investigators and the NCI of the positive results and the findings are being released based on their impact on the treatment of APL. A complete scientific presentation of these study results is planned for the annual meeting of the American Society of Clinical Oncology (ASCO) in June 2007.

Dr. Lesley Russell, Executive Vice President, Worldwide Medical and Regulatory Operations, Cephalon, said, "The results of this study showing a survival benefit associated with the use of TRISENOX in patients with APL are an important development for physicians and patients, as demonstrated by the urgency to disseminate the results to clinicians in an expedited manner. We are encouraged by the oncology community's continued interest in the potential of TRISENOX, and these study results reinforce Cephalon's commitment to build a fully integrated oncology business."

TRISENOX is indicated for the induction of remission and consolidation in patients with APL who are refractory to, or have relapsed from, retinoid and anthracycline chemotherapy, and whose APL is characterized by the presence of the t(15;17) translocation of PML/RAR-alpha gene expression. Full prescribing information, including boxed warning, is available at http://www.TRISENOX.com. While Cephalon is evaluating these study results as well as other areas of interest to consider future development of TRISENOX, the product is not presently indicated or approved by the U.S. Food and Drug Administration (FDA) for use in any other disease or related cancer beyond its labeled indications.

In addition to TRISENOX, the Cephalon Oncology therapeutic portfolio in the United States includes two other compounds in late-stage clinical development: TREANDA(R) (bendamustine HCl), a bi-functional cytotoxic in phase 3 development for chronic lymphocytic leukemia (CLL) and non-Hodgkins lymphoma (NHL), and CEP-701 (lestaurtinib), an oral small molecule inhibitor of tyrosine kinases including FLT-3, TRK and JAK-2, in phase 3 development for acute myeloid leukemia (AML). Neither compound is presently indicated or approved by the FDA for these or any other diseases.

Cephalon, Inc.

Founded in 1987, Cephalon, Inc. is an international biopharmaceutical company dedicated to the discovery, development and marketing of innovative products in four core therapeutic areas: central nervous system, pain, oncology and addiction. Cephalon currently employs approximately 3,000 people in the United States and Europe. U.S. sites include the company'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 in Maisons-Alfort, France.

The company currently markets six proprietary products in the United States: PROVIGIL(R) (modafinil) Tablets [C-IV], FENTORA(TM) (fentanyl buccal tablet) [C-II], TRISENOX, VIVITROL(R) (naltrexone for extended-release injectable suspension), GABITRIL(R) (tiagabine hydrochloride), ACTIQ(R) (oral transmucosal fentanyl citrate) [C-II], and numerous products internationally.

In addition to historical facts or statements of current condition, this press release may contain forward-looking statements. Forward-looking statements provide Cephalon's current expectations or forecasts of future events. These may include statements regarding anticipated scientific progress on its research programs; development of potential pharmaceutical products; interpretation of clinical results, including the results of the NCI/CALGB study of TRISENOX; prospects for regulatory approval, including with respect to any potential future indications for TRISENOX; manufacturing development and capabilities; market prospects for its products; sales and earnings guidance; and other statements regarding matters that are not historical facts. You may identify some of these forward-looking statements by the use of words in the statements such as "anticipate," "estimate," "expect," "project," "intend," "plan," "believe" or other words and terms of similar meaning. Cephalon's performance and financial results could differ materially from those reflected in these forward-looking statements due to general financial, economic, regulatory and political conditions affecting the biotechnology and pharmaceutical industries as well as more specific risks and uncertainties facing Cephalon such as those set forth in its reports on Form 8-K, 10-Q and 10-K filed with the U.S. Securities and Exchange Commission. Given these risks and uncertainties, any or all of these forward-looking statements may prove to be incorrect. Therefore, you should not rely on any such factors or forward-looking statements. Furthermore, Cephalon does not intend to update publicly any forward-looking statement, except as required by law. The Private Securities Litigation Reform Act of 1995 permits this discussion.

Cephalon, Inc.
http://www.cephalon.com