PRESS RELEASE: Endo Announces Positive Results From Interim Analysis of RAPINYL Phase III Clinical Trial

Endo Announces Positive Results From Interim Analysis of RAPINYL Phase III Clinical Trial

Endo Pharmaceuticals Inc., a market leader in pain management and a wholly owned subsidiary of Endo Pharmaceuticals Holdings Inc. (NASDAQ: ENDP), today reported positive results from the previously announced, planned interim statistical analysis of a Phase III, placebo-controlled, double-blind trial of its development product, RAPINYL(TM). The data from the analysis of 61 patients demonstrated that RAPINYL met its primary endpoint, the Sum of Pain Intensity Difference from baseline to 30 minutes (SPID 0-30), and the results were highly statistically significant (p=0.0004). In addition, all the secondary endpoints were met. Statistically significant separation from placebo on mean pain intensity difference was seen as early as 10 minutes.

On the basis of these results and in accordance with the predetermined criteria of the interim analysis, Endo is terminating enrollment in the double-blind crossover portion of this clinical study. Enrollment is continuing in the safety portion of this trial and a second Phase III trial to meet the requirements for additional safety data. RAPINYL is an oral, fast-dissolving tablet of fentanyl intended for the treatment of breakthrough cancer pain. Endo licensed the exclusive rights to develop and market RAPINYL in North America from Orexo AB.

"We are extremely pleased by the outcome of this analysis, which we believe demonstrates that RAPINYL can be an effective treatment for breakthrough pain in cancer patients," said David A. Lee, M.D., Ph.D., Chief Scientific Officer. "We remain confident that RAPINYL's quick dissolution and rapid absorption profile make it a potentially attractive treatment for breakthrough cancer pain." He added that Endo will conduct a thorough analysis of the data to determine the next course of action, including the possibility of filing a New Drug Application (NDA) based on these results. It expects to provide further updates on the status of the RAPINYL clinical development program early in 2008.

The company noted that although this planned interim analysis was only intended to determine efficacy and not tolerability, those adverse events that were reported were consistent with what is usually observed with other opioids.

About Endo

A wholly owned subsidiary of Endo Pharmaceuticals Holdings Inc., Endo Pharmaceuticals is a fully integrated specialty pharmaceutical company with market leadership in pain management products. The company researches, develops, produces and markets a broad product offering of branded and generic pharmaceuticals, meeting the needs of healthcare professionals and consumers alike. More information, including this and past press releases of Endo Pharmaceuticals Holdings Inc., is available online at

Forward-Looking Statements

This press release contains forward-looking statements, within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, as amended, that are based on management's beliefs and assumptions, current expectations, estimates and projections. Statements that are not historical facts, including statements which are preceded by, followed by, or that include, the words "believes," "anticipates," "plans," "expects" or similar expressions and statements are forward-looking statements. Endo's estimated or anticipated future results, product performance or other non-historical facts are forward-looking and reflect Endo's current perspective on existing trends and information. Many of the factors that will determine the Company's future results are beyond the ability of the Company to control or predict. These statements are subject to risks and uncertainties and, therefore, actual results may differ materially from those expressed or implied by these forward-looking statements. The reader should not rely on any forward-looking statement. The Company undertakes no obligation to update any forward-looking statements whether as a result of new information, future events or otherwise. Several important factors, in addition to the specific factors discussed in connection with these forward-looking statements individually, could affect the future results of Endo and could cause those results to differ materially from those expressed in the forward-looking statements contained in this press release. Important factors that may affect future results include, but are not limited to: market acceptance of the Company's products and the impact of competitive products and pricing; dependence on sole source suppliers; the success of the Company's product development activities and the timeliness with which regulatory authorizations and product launches may be achieved; successful compliance with extensive, costly, complex and evolving governmental regulations and restrictions; the availability on commercially reasonable terms of raw materials and other third party manufactured products; exposure to product liability and other lawsuits and contingencies; dependence on third party suppliers, distributors and collaboration partners; the ability to timely and cost effectively integrate acquisitions; uncertainty associated with pre-clinical studies and clinical trials and regulatory approval; uncertainty of market acceptance of new products; the difficulty of predicting FDA approvals; risks with respect to technology and product development; the effect of competing products and prices; uncertainties regarding intellectual property protection; uncertainties as to the outcome of litigation; a determination by a regulatory agency that we are engaging in inappropriate sales or marketing activities, including promoting the "off-label" use of our products; changes in operating results; impact of competitive products and pricing; product development; changes in laws and regulations; customer demand; possible future litigation; availability of future financing and reimbursement policies of government and private health insurers and others; and other risks and uncertainties detailed in Endo's filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K filed with the SEC on March 1, 2007. Readers should evaluate any statement in light of these important factors.