IMPAX Receives Tentative FDA Approval for Generic Rilutek

July 22, 2002
IMPAX's Fourth Tentative ANDA Approval This Year

July 22, 2002 -- IMPAX Laboratories, Inc. (Nasdaq NM: IPXL) today announced that the U.S. Food and Drug Administration (FDA) has granted tentative approval to the Company's Abbreviated New Drug Application (ANDA) for a generic version of Rilutek® (Riluzole 50mg) tablets. Aventis Pharmaceutical Products, Inc. markets Rilutek® for the treatment of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease. According to IMS Health, U.S. sales of Rilutek were $35 million for the 12 months ended March 31, 2002.

Final FDA approval is contingent upon the expiration of Orphan Drug Exclusivity on December 12, 2002, resolution of the patent litigation that IMPAX has initiated against Aventis regarding a patent recently listed by Aventis in the FDA "Orange Book," as well as FDA's evaluation of any new information subsequent to this tentative approval.

"This is our fourth ANDA tentative approval this year, and we are pleased with the progress we are making in our development and commercialization strategy," said Larry Hsu, Ph.D., President and Chief Operating Officer of IMPAX Laboratories. "The development of our generic version of Rilutek® is consistent with our strategy to develop niche products we believe will have limited competition. Upon final approval, we anticipate that our Global Pharmaceuticals division will market the product."

IMPAX currently has 17 ANDA filings pending at the FDA that address more than $9 billion in U.S. branded product sales. Ten of these filings were made under Paragraph IV of the Hatch-Waxman Amendments and four of these 17 ANDAs now have received tentative approval from the FDA.

IMPAX Laboratories, Inc. is a technology based specialty pharmaceutical company applying its formulation expertise and drug delivery technology to the development of controlled-release and niche generics in addition to the development of branded products. IMPAX markets its generic products through its Global Pharmaceuticals division and intends to market its branded products through the IMPAX Pharmaceuticals division. IMPAX Laboratories is headquartered in Hayward, California, and has a full range of capabilities in its Hayward and Philadelphia facilities. For more information, please visit the Company's Web site at: