Impax Pharmaceuticals, a division of Impax Laboratories, Inc. (NASDAQ: IPXL), announced today that the U.S. Food and Drug Administration (FDA) issued a complete response letter regarding the New Drug Application (NDA) for RYTARY™ (IPX066), an extended-release capsule formulation of carbidopa-levodopa, a potential treatment for the symptomatic treatment of Parkinson’s disease currently under review in the United States. The complete response letter indicates that the FDA requires a satisfactory re-inspection of the company’s Hayward facility as a result of the warning letter issued in May 2011 before the company’s NDA may be approved due to the facility’s involvement in the development of RYTARY, and supportive manufacturing and distribution activities. During the assessment of the NDA, the company withdrew the Hayward site as an alternative site of commercial production at launch. “We will work with the FDA on the appropriate next steps for the RYTARY application,” said Larry Hsu, Ph.D., president and CEO, Impax Laboratories, Inc. “We remain committed to resolving the warning letter and bringing this new treatment option to patients who are suffering from Parkinson’s disease.” A complete response letter is issued by the FDA’s Center for Drug Evaluation and Research when the review cycle for a drug is complete and the application is not yet ready for approval. About RYTARY TM (IPX066) RYTARY is an investigational extended-release capsule formulation of carbidopa-levodopa for the treatment of idiopathic Parkinson’s disease. It is not approved or licensed anywhere in the world. Results from the phase III studies of IPX066, APEX-PD (early PD), ADVANCE-PD (advanced PD) and ASCEND-PD (advanced PD) have previously been announced. RYTARY has been licensed to GlaxoSmithKline (GSK) for countries outside the U.S. and Taiwan for development and marketing. A bout the Impax GSK collaboration Impax Pharmaceuticals and GSK announced an agreement for the development and commercialization of IPX066 in December 2010. Under the terms of the agreement, GSK received an exclusive license to register and commercialize IPX066 throughout the world except in the U.S. and Taiwan.