Axonyx Reports Phenserine Associated with Significant Amyloid Reduction in Phase I Trial; Results Support Dual Mechanisms of Action.

NEW YORK -- Axonyx Inc. (NASDAQ:AXYX) today reported a significant reduction in the plasma levels of beta-amyloid 1-42 (A beta-42) in healthy human subjects treated with Phenserine for 35 days. This additional analysis was recently completed as part of the program to identify a partner for the further development of Phenserine.

Six healthy men and six healthy women were enrolled in this multiple-dose Phase I study. Subjects were treated with Phenserine 10mg twice daily for 28 days and Phenserine 15mg twice daily for an additional week. Plasma samples were collected on Days 1, 28, 29, and 35, with plasma A beta-42 assessments available for 11 subjects. Samples were collected in accordance with a pre-defined pharmacokinetic sampling schedule.

Sample day                                   Plasma A beta-42
                                           Mean (pg/mL)+/- SEM
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Day 1 (prior treatment)                       102.2 +/- 2.6
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Day 35 (prior treatment)                      101.9 +/- 2.8
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Day 35 (2 hrs post treatment)                 81.3 +/- 6.2(a)
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((a) p less than 0.01 relative to baseline)

At two hours following dosing on Day 35, there was a statistically significant decrease of A beta-42 relative to pre-treatment levels (p less than 0.01). This effect was observed at approximately 30 minutes after the time of maximal plasma Phenserine concentrations. Furthermore, the decline in plasma A beta-42 concentrations on day 35 consistently coincided with the increase in plasma Phenserine concentrations following dosing. There were no unexpected safety or tolerability concerns associated with Phenserine treatment in the 12 healthy subjects.

Amyloid is thought by many to be key in the development and progression of AD and reduction of A beta-42 may potentially result in slowing the onset and progression of the disease. The Company previously reported interim analyses of its Phase IIb beta amyloid trial, which appeared to show an effect of Phenserine on levels of beta amyloid, although the variability of data in that study and the size of that trial could not support the potential of a statistically significant outcome. While the absence of a placebo group in the results reported today calls for caution when interpreting these results, they are consistent with effects of Phenserine on A beta-42 observed in pre-clinical placebo controlled studies. Thus, the Company considers these results to support Phenserine's dual mechanisms of action, which would differentiate it as a potential treatment for Alzheimer's disease.

About Phenserine

Phenserine is a highly selective inhibitor of acetylcholinesterase (AChEI), an enzyme that breaks down the neurotransmitter acetylcholinesterase, a neurotransmitter important to memory and cognitive function. Unlike other AChEI's, which only suppress the activity of the enzyme, Phenserine has been shown to have two mechanisms of action: (1) the inhibition of the AChE enzyme, and (2) an ability to lower levels of beta-amyloid- a peptide thought to play a key role in causing the alterations in the brain which lead to the symptoms and progression of Alzheimer's disease.

About Axonyx

Axonyx Inc. is a U.S.-based biopharmaceutical company engaged in the acquisition and development of proprietary pharmaceutical compounds for the treatment of Central Nervous System disorders. The Company currently has three compounds in development for Alzheimer's disease, namely Phenserine -- a potential symptomatic and disease progression treatment of mild to moderate Alzheimer's Disease (AD), Posiphen(TM) -- a potential disease progression treatment for AD now in Phase I, and BisNorCymserine (BNC) -- a potential symptomatic treatment of severe AD now in pre-Investigational New Drug (IND) stage. The Company is looking to identify licensing partners to further the development of Phenserine.

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. Specifically, with respect to our drug candidates Phenserine, Posiphen(TM) and BisNorCymserine, Axonyx cannot assure that: any preclinical studies or clinical trials, whether ongoing or conducted in the future, will prove successful, and if successful, that the results can be replicated; safety and efficacy profiles of any of its drug candidates will be established, or if established, will remain the same, be better or worse in future clinical trials, if any; pre-clinical results related to cognition and the regulation of beta-APP will be substantiated by ongoing or future clinical trials, if any, or that any of its drug candidates will be able to improve the signs or symptoms of their respective clinical indication or slow the progression of Alzheimer's disease; any of its drug candidates will support an NDA filing, will be approved by the FDA or its equivalent, or if approved, will prove competitive in the market; or that Axonyx will have or obtain the necessary financing to support its drug development programs. 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.