Axonyx Reports Statistically Significant Result for Phenserine in Alzheimer's Disease; Additional Analysis Results from Curtailed Phase III Clinical Trials

Axonyx Inc. (NASDAQ: AXYX) reports today the results ofan additional analysis of a subgroup of patients from its twocurtailed Phase III clinical trials (AX-CL-09/010) with Phenserine, indevelopment for mild to moderate Alzheimer's disease (AD). Thesubgroup of patients, who received Phenserine 15mg twice daily,demonstrated a statistically significant benefit over placebo asmeasured by the Alzheimer's Disease Assessment Scale-cognitivesubscale (ADAS-cog), when treated for more than 12 weeks.Additionally, this subgroup showed a positive trend towardsimprovement in the Clinical Interview Based Impression of Change(CIBIC+) test, which approached statistical significance. There wereno unexpected safety or tolerability concerns associated withPhenserine treatment. This analysis was undertaken in addition to thepreviously announced results of the primary pre-defined statisticalanalysis.

While additional clinical trials would be required to furtherconfirm the results of this additional analysis, the Company believesthat they support its stated position that higher doses of Phenserinecould potentially be efficacious in treating the signs and symptoms ofmild to moderate AD in future potential Phase III trials of 26 weeksduration.

On September 20, 2005, the Company announced the top line resultsfrom its primary efficacy analysis of all patients that participatedin the curtailed Phase III clinical trials; this analysis did notdemonstrate a statistically significant benefit associated withPhenserine over placebo after 12 weeks of treatment in either theADAS-cog or CIBIC+, the primary efficacy endpoints for the study. Atthat time, the Company indicated that it would continue to evaluatethe Phenserine program. On November 7, 2005, the Company indicated itwould not commit further resources to the development of Phenserineand would seek a partner for the compound.

This additional analysis was recently completed as part of theprogram to identify a partner for the further development ofPhenserine. The analysis included 182 patients who received Phenserinetreatment or placebo for more than 12 weeks and up to 26 weeks oftreatment. The statistically significant benefit was based on theADAS-cog test; one of the FDA approved measurements of efficacy inAlzheimer's disease clinical trials. The improvement in the CIBIC+test, another approved efficacy endpoint, for the 15mg twice dailygroup approached statistical significance compared to the placebogroup. The patients who received Phenserine 10mg twice daily did notshow a statistically significant benefit compared to placebo.

Details of the secondary analysis results are provided in thechart below. For the ADAS-cog, more negative values indicate greaterimprovement of cognition. For CIBIC+ lower values indicate greaterimprovement.
Mean Changes from Baseline to Last Visit in the Post Week 12 Patient
Subgroup
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15-mg Mean Difference
Endpoint Twice Daily Placebo 15mg vs. Placebo P - value(c)
n = 54 n = 66 (+/-95% Confidence Intervals)
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ADAS-cog(a) -3.18 -0.66 -2.52 (-4.92 to -0.12) 0.0296
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CIBIC+(b) 3.59 3.95 -0.36 (-0.76 to 0.04) 0.0568
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a) Ranked ANCOVA model with centre and baseline covariates.
b) Cochran-Mantel-Haenzsel test incorporating rank scores.
c) Statistical significance is defined as a P value of 0.05 or
less.

Phenserine is a highly selective acetylcholinesterase inhibitor(AChE-I) that breaks down a neurotransmitter in the brain important inmemory and cognition. Unlike other AChE-I's which only suppress theactivity of the enzyme, Phenserine has been shown to have twomechanisms of action: (1) the inhibition of the AChE enzyme, and (2)in preclinical studies the inhibition of the synthesis of A beta, theprotein in the brain that is thought by many to be a potential causeof Alzheimer's disease and its progression.

About Axonyx

Axonyx Inc. is a U.S.-based biopharmaceutical company engaged inthe acquisition and development of proprietary pharmaceuticalcompounds for the treatment of Central Nervous System disorders. TheCompany currently has three compounds in development for Alzheimer'sdisease, namely Phenserine - a potential symptomatic and diseaseprogression treatment of mild to moderate Alzheimer's Disease (AD),Posiphen(TM) - a potential disease progression treatment for AD now inPhase I, and BisNorCymcerine (BNC) - a potential symptomatic treatmentof severe AD now in pre-Investigational New Drug (IND) stage.

This press release may contain forward-looking statements orpredictions. These statements represent our judgment to date, and aresubject to risks and uncertainties that could materially affect theCompany, including those risks and uncertainties described in thedocuments Axonyx files from time to time with the SEC, specificallyAxonyx's annual report on Form 10-K. Specifically, with respect to ourdrug candidates Phenserine, Posiphen(TM) and BisNorCymcerine, Axonyxcannot assure that: any preclinical studies or clinical trials,whether ongoing or conducted in the future, will prove successful, andif successful, that the results can be replicated; safety and efficacyprofiles of any of its drug candidates will be established, or ifestablished, will remain the same, be better or worse in futureclinical trials, if any; pre-clinical results related to cognition andthe regulation of beta-APP will be substantiated by ongoing or futureclinical trials, if any, or that any of its drug candidates will beable to improve the signs or symptoms of their respective clinicalindication or slow the progression of Alzheimer's disease; any of itsdrug candidates will support an NDA filing or its equivalent, will beapproved by the FDA or its equivalent, or if approved, will provecompetitive in the market; or that Axonyx will have or obtain thenecessary financing to support its drug development programs. Axonyxcannot assure that it will be successful with regard to identifying a(sub-) licensing partner for any of its compounds. Axonyx undertakesno obligation to publicly release the result of any revisions to suchforward-looking statements that may be made to reflect events orcircumstances after the date hereof or to reflect the occurrence ofunanticipated events.