IMPAX Comments On Lawsuit Filed by Glaxo Wellcome Related to Generic Versions of Wellbutrin SR and Zyban

Business Wire, Oct 10, 2000

Business Editors/Legal, Health & Medical Writers

HAYWARD, Calif.--(BW HealthWire)--Oct. 10, 2000

IMPAX Laboratories Inc. (NASDAQ NM: IPXL) today announced that Glaxo Wellcome, Inc., a wholly owned subsidiary of Glaxo Wellcome, plc (NYSE: GLX), has filed a lawsuit against the Company in the Northern District of California alleging patent infringement related to IMPAX's filing of Abbreviated New Drug Applications (ANDA) for generic versions of Wellbutrin SR(R) (bupropion hydrochloride) Sustained-Release Tablets and Zyban(R) (bupropion hydrochloride) Sustained-Release Tablets. Glaxo Wellcome markets Wellbutrin SR for the treatment of depression and markets Zyban as an aid in smoking cessation.

During 1999, U.S. sales of Wellbutrin SR exceeded $530 million and sales of Zyban were nearly $110 million. IMPAX's ANDA filings with the Food and Drug Administration (FDA) contain Paragraph IV certifications under the Hatch-Waxman Amendments stating IMPAX's belief that its bupropion hydrochloride extended release tablets do not infringe the Glaxo Wellcome listed patents on Wellbutrin SR and Zyban.

"The patents listed for Wellbutrin SR and Zyban relate to the method of formulating these products. We are very confident that our formulation does not infringe the Glaxo Wellcome patent," said Barry R. Edwards, Co-Chief Executive Officer of IMPAX Laboratories.

"It has been estimated that in the next few years branded pharmaceutical companies will lose patent protection on drugs with over $25 billion in annual sales," continued Mr. Edwards. "The filing of patent-infringement lawsuits is just one of the tactics these companies use in an attempt to extend marketing exclusivity of a product. Therefore, although we believe this suit is without merit, we are not surprised by its filing." IMPAX currently has submitted eight ANDA filings to the FDA addressing approximately $4.2 billion in U.S. branded product sales.

IMPAX Laboratories, Inc. combines the advanced drug delivery systems developed by Impax Pharmaceuticals with the packaging, marketing and sales capabilities of Global Pharmaceuticals. The Company continues to expand its development of niche and controlled-release generics while accelerating the development of branded products. IMPAX Laboratories is headquartered in Hayward, Calif., and has a full range of capabilities in its Hayward and Philadelphia facilities. For more information, please visit the Company's Web site at www.impaxlabs.com.

"Safe Harbor" statement under the Private Securities Litigation Reform Act of 1995:

To the extent any statements made in this release contain information that is not historical, these statements are essentially forward-looking and are subject to risks and uncertainties, including the difficulty of predicting FDA filings and approvals, acceptance and demand for new pharmaceutical products, the impact of competitive products and pricing, new product development and launch, reliance on key strategic alliances, availability of raw materials, the regulatory environment, fluctuations in operating results and other risks detailed from time to time in the Company's filings with the Securities and Exchange Commission.