Axonyx Reports Data on Effects of Phenserine on the Brains of Alzheimer's Disease Patients; PET Scans Show Increased Brain Neuron Activity and Reduced Amyloid Load

A double-blind, placebo-controlled pilot study, using PositronEmission Tomography (PET), examined the effects of Phenserinetreatment on the brains of 20 AD patients (Phenserine 15mg BID, 10patients; and placebo, 10 patients). PET is an imaging technique thatprovides information about physiological and biochemical processes.Two different aspects brain changes were assessed; 1) Changes in brainglucose metabolism using 18F-fluorodeoxyglucose (FDG), and 2) Changesin the level of brain amyloid load using (11C)-PIB (PittsburghCompound B).

There was a statistically significant increase in glucosemetabolism as compared to baseline in the frontal and parietalcortical areas in the brains of Phenserine patients, while the placebogroup did not show any significant changes from baseline. Theseobserved changes were highly correlated with the statisticallysignificant improvement in the Digit Symbol test of attention, anability that resides in the frontal cortex. The accumulation of FDG isa direct measure of the metabolic activity of neurons and is known tochange in parallel with neuronal function. Patients with AD havecharacteristic reductions in FDG measurements of regional brainactivity, which are progressive and correlate to dementia severity.

Baseline PIB PET scans showed a statistically significant increasein retention in the most AD relevant brain regions compared to agematched healthy historical controls, thus confirming that the includedpatients were suffering from AD. PET studies with the amyloid-imagingligand (11C)-PIB have shown a difference in PIB retention in brains ofAD patients compared to healthy controls. A trend to a decreasedamyloid load was observed in Phenserine treated patients as comparedto baseline whereas the placebo group did not change. In addition, aninverse correlation was found between glucose metabolism and amyloidload, confirming historical published data. The deposition ofbeta-amyloid is one of the key pathological features of AD. Trackingthe beta-amyloid load in the brains of AD patients with PET is apromising strategy for imaging the specific disease process.

"This is the first time that a treatment for AD is being studiedusing the amyloid imaging compound where an effect has been measured,"said Prof. Dr. Agneta Nordberg, MD, PhD of the Karolinska Institute,"The results to date are promising and we look forward to the furtheranalyses of the scans and spinal fluid and at the end of 6 months oftreatment."

While these data are the result of an interim analysis conductedafter 13 weeks of double blind treatment, the Company believes thatthese data provide encouraging signals associated with metabolic andpotential amyloid reducing effects of Phenserine. The study iscontinuing and the patients will be evaluated again following a totalof 6 months of treatment. Additional analyses of the above PET scandata are currently being undertaken, and an examination of the spinalfluid of these patients is planned.

About Phenserine

Phenserine is a highly selective inhibitor of acetylcholinesterase(AchE-I), an enzyme that breaks down the neurotransmitteracetylcholine, a neurotransmitter important to memory and cognitivefunction. Unlike other AchE-I's, which only suppress the activity ofthe enzyme, Phenserine has been shown to have two mechanisms ofaction: (1) the inhibition of the AChE enzyme, and (2) inhibition ofthe synthesis of A beta - a protein thought 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; Phenserine - a potential symptomatic and disease progressiontreatment of mild to moderate Alzheimer's disease (AD); Posiphen(TM) -a potential disease progression treatment for AD now in Phase I; andBisNorCymcerine (BNC) - a potential symptomatic treatment of severe ADin the 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 BisNorCymserine, 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 and/or amyloid beta will be substantiatedby ongoing or future clinical trials, if any, or that any of its drugcandidates will be able to improve the signs or symptoms of theirrespective clinical indication or slow the progression of Alzheimer'sdisease; any of its drug candidates will support an NDA filing, willbe approved by the FDA or its equivalent, or if approved, will provecompetitive in the market; Axonyx will be able to successfullyout-license any of its drug candidates; Axonyx will be able tosuccessfully in-license any additional compounds; or that Axonyx willhave or obtain the necessary financing to support its drug developmentprograms. Axonyx cannot assure that it will be successful with regardto identifying a (sub-) licensing partner for any of its compounds.Axonyx undertakes no obligation to publicly release the result of anyrevisions to such forward-looking statements that may be made toreflect events or circumstances after the date hereof or to reflectthe occurrence of unanticipated events.