Researcher Reports Data on Effects of Posiphen(TM) on Human Neuronal Stem Cells; Posiphen May Support Stem Cell Transplantation

Axonyx Inc. (NASDAQ: AXYX) today announced the results
of an independent study showing that Posiphen increased the ability of
transplanted human neuronal stem cells (HNSC) to differentiate into
neurons in APP transgenic mice, a model of Alzheimer's disease (AD) in
humans. The research was reported by Kiminobu Sugaya, Ph.D., Professor
of Molecular Biology, Biomolecular Sciences Center, University of
Central Florida, Orlando, Florida at the 9th International
Geneva/Springfield Symposium on Advances in Alzheimer's Disease held
April 19 - 22, 2006 in Geneva, Switzerland.
   Dr. Sugaya's research showed that when APP transgenic mice had
been pre-treated with Posiphen, transplanted HNSC start to
differentiate into neurons in the brain area where they are needed.
When HNSC were transplanted into the brains of APP transgenic mice in
the absence of Posiphen, HNSC did not differentiate into neurons. Dr.
Sugaya attributed this effect to Posiphen's ability to decrease the
synthesis of amyloid precursor protein (APP). Posiphen may support and
augment production of the new neurons through the suppression of APP
production in the brain. The differentiation of stem cells into
functioning neurons is critical to the success of stem cell therapy of
AD.
   "Although a better understanding of the mechanisms of APP function
HNSC biology may be needed", stated Dr. Kiminobu Sugaya, "regulation
of APP levels by a combination of Posiphen and stem cell treatments
could be a promising strategy to treat AD."

   About Posiphen(TM)

   Posiphen is in Phase I clinical development by Axonyx for the
potential treatment of AD progression and is the positive isomer of
Phenserine. Posiphen treatment, similar to Phenserine, has been shown
to lower secreted and cellular APP and secreted Amyloid beta (A beta)
levels in neuronal cells in culture as well as in vivo studies in
mice, where brain levels of both APP and A beta were significantly and
dose-dependently lowered by Posiphen over a wide range of doses that
were well tolerated.

   About Alzheimer's Disease

   Alzheimer's disease is typified by a progressive impairment in
memory, cognition and emotional disturbances that result from the
dysfunction and death of neurons in the brain. This pathology is
considered, in part, to be the result of the over production and
accumulation of beta amyloid (A beta) in and between neurons. Beta
amyloid, a result of the cleavage of APP, subsequently aggregates to
form plaques that are a microscopic hallmark of AD and have been
postulated to have a causative role in AD.

   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; 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
BisNorCymcerine (BNC) - a potential symptomatic treatment of severe AD
in the pre-Investigational New Drug (IND) stage.

   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 and/or amyloid beta 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; Axonyx will be able to successfully
out-license any of its drug candidates; Axonyx will be able to
successfully in-license any additional compounds; or that Axonyx will
have or obtain the necessary financing to support its drug development
programs. Axonyx cannot assure that it will be successful with regard
to identifying a (sub-) licensing partner for any of its compounds.
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.