Axonyx Announces Results of Blinded Data Review of Beta Amyloid Clinical Trial for Alzheimer's Disease; Original Statistical Assumptions Confirmed.

Business Editors/Health/Medical Writers

NEW YORK--(BUSINESS WIRE)--May 6, 2004

Axonyx Inc. (NASDAQ: AXYX) today announced that the blinded data review that statistically reassessed the original variability estimate of the available data from the ongoing Phase IIB Amyloid beta (A(B)) trial with Phenserine confirmed the original power requirements and the ability of the study to achieve its objectives. As previously announced, it is expected that results pertaining to the effect of Phenserine on the levels of beta amyloid and beta-amyloid precursor protein (beta-APP) in the plasma and cerebrospinal fluid (CSF) will be available at the end of the year.

This 6-month randomized placebo-controlled double-blind trial is evaluating the effects of two different dosages of Phenserine on the levels of the beta APP and A(B) in the plasma and CSF of mild to moderate Alzheimer's disease (AD) patients. The original target number of patients to be completed for statistical analysis was 65. All recruited patients will be allowed to complete 6 months of treatment with Phenserine and would be eligible to participate in the open label extension study.

This Phase IIB trial is intended to substantiate in vitro and in vivo preclinical data that has consistently shown that Phenserine can reduce the levels of beta-APP and beta amyloid. It is believed by many experts in the field that one of the key underlying pathological processes in AD is associated with the amyloid cascade and inhibition of this process could potentially modify AD progression. Patients in this trial also undergo testing with the standard memory and cognition tests recommended by the United States FDA and European regulatory authorities.

"We have yet to fully exploit the therapeutic potential of the cholinesterase inhibiting drug class," stated Professor Ezio Giacobini, member of the Axonyx Steering Committee. "It is refreshing to see the potential represented by Phenserine as a new approach for AD treatment."

"We are very pleased with the outcome of the blinded data review of Phenserine's potential effect on beta amyloid," stated Gosse B. Bruinsma, MD, President and COO. "We believe that the potential effect of Phenserine on amyloid biomarkers in the CSF of AD patients will be a strong signal that Phenserine may have the ability to modify AD progression."

About Axonyx

Axonyx Inc. is a U.S.-based biopharmaceutical company engaged in the acquisition and development of proprietary pharmaceutical compounds and new technologies useful in the diagnosis and treatment of Alzheimer's disease, human memory disorders and prion-based illnesses such as Mad Cow disease. Its leading Alzheimer's disease drug candidate is Phenserine, a dual action acetylcholinesterase and beta amyloid precursor protein ((B)-APP) inhibitor, and currently in Phase IIB and Phase III clinical trials. A previously completed Phase II trial showed that Phenserine was well tolerated and effective in improving the memory of mild-to-moderate AD patients.

The ongoing Phase IIB clinical study is designed to evaluate Phenserine's ability to lower the levels of the beta-amyloid precursor protein ((B)-APP) and Amyloid beta (A-(B)) in the plasma and cerebrospinal fluid of mild-to-moderate AD patients. The presence of toxic beta-amyloid in the brains of AD patients is considered by many experts to be a key pathological event in the causation as well as the progression of AD. A reduction of these levels may be able to slow the progression of AD.

This press release may contain forward-looking statements or predictions. These statements represent our judgment to date, and are subject to risks and uncertainties that could materially affect the Company including those risks and uncertainties described in the documents Axonyx files from time to time with the SEC, specifically Axonyx's annual report on Form 10-K. Axonyx cannot assure that the Phase IIB and/or the Phase III clinical trial, or others, if any, with Phenserine will prove successful, that the safety and efficacy profile of Phenserine exhibited in the previous small Phase II trial will remain the same in the Phase IIB and Phase III clinical trials, or future clinical trials, if any, that the preclinical results related to the regulation of beta-APP will be substantiated by the Phenserine Phase IIB clinical trial and that Phenserine will be able to slow the progression of Alzheimer's disease, that the Phase IIB clinical trial data will differentiate Phenserine from the currently marketed drugs, that the efficacy results of the Phase III trial will prove pivotal, that the efficacy data from the Phase IIB clinical trial will be able to be used in the Phase III trial efficacy data, that Axonyx will obtain the necessary financing to complete the Phase III Phenserine trials, that the Company's development work on Phenserine will support an NDA filing, that the results of the Phase III trials will allow Phenserine to be approved by the FDA, that the FDA will grant marketing approval for Phenserine, that if Phenserine is approved by the FDA, it will prove competitive in the market, and that Axonyx will obtain licensing or corporate partnership agreements that will enable acceleration of the development of and optimize marketing opportunities for, Phenserine, or that Axonyx will be able to advance any other potential memory enhancing compound toward IND status. Axonyx undertakes no obligation to publicly release the result of any revisions to such forward-looking statements that may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.