terms of schizophrenia deal with ortho-mcneil-janssen pharmaceuticals, inc. disclosed for the first time.
oral glp-1 receptor positive allosteric modulator effective in preclinical models of diabetes.
mglur4 positive allosteric modulators demonstrate efficacy in preclinical model of anxiety.
il-1 receptor negative allosteric modulators identified.

Geneva, Switzerland, 11 May 2010 - Allosteric modulation company Addex Pharmaceuticals Ltd (SIX:ADXN) is holding its annual R&D Day today at its headquarters starting at 11am CET. Webcasts of the presentations will be available in live and recorded forms via www.addexpharma.com.

“The exciting progress in our programs partnered with Ortho-McNeil-Jansen Pharmaceuticals, Inc. and Merck & Co., Inc., as well as the innovative breakthroughs in un-partnered discovery programs show that the fundamentals of our platform for allosteric drug discovery and development are stronger than ever,” CEO Vincent Mutel said.

The company will discuss new data and/or the status of multiple clinical and preclinical stage programs including:

• ADX48621 is scheduled to start in 2010 Phase II testing in patients with Parkinson’s disease levodopa-induced dyskinesia (PD-LID) and Phase IIa testing in patients with dystonia. ADX48621 is an mGluR5 negative allosteric modulator (NAM) wholly owned by Addex. Inhibition of mGluR5 is a clinically validated mechanism in PD-LID.
  
  
• ADX71149 is expected to start Phase IIa testing for schizophrenia and anxiety in 2010, subject to the successful completion of the ongoing Phase I program and regulatory approvals. Addex disclosed today for the first time that, under the terms of the partnership with Ortho-McNeil-Janssen Pharmaceuticals, Inc. (OMJPI), Addex is eligible for up to €112 million subject to successful completion of development and regulatory milestones. In addition, Addex is eligible for low double-digit royalties on sales of ADX71149, subject to regulatory approval and successful commercial launch. ADX71149 is an mGluR2 positive allosteric modulator (PAM) being developed by OMJPI. Activation of mGluR2 is a clinically validated mechanism in both schizophrenia and anxiety.
  
  
• Data released today for the first time, from the collaboration with Merck & Co., Inc. to develop mGluR4 PAM for treatment of Parkinson’s disease and other indications, show that orally available mGluR4 PAM reduced anxiety in a preclinical model. Parkinson’s disease patients often suffer from anxiety and depression.
  
  
• Data released today for the first time, show that GLP-1 receptor (GLP1R) PAM significantly enhanced insulin secretion and significantly reduced the rise in plasma glucose following glucose administration in the “db/db” preclinical model of Type II diabetes.
  
  
• Addex disclosed today for the first time that it has identified IL-1 receptor (IL1R) negative allosteric modulators and, in using its proprietary screening tool, ADX-tags 1, identified as an IL1R NAM a known anti-inflammatory molecule, which had not previously been identified as an IL1R antagonist.

Addex Pharmaceuticals (www.addexpharma.com) discovers and develops allosteric modulators for human health and is focused on validated therapeutic targets for diseases of the central nervous system, metabolic disorders and inflammation. Subject to the completion of Phase I testing and regulatory approvals, Phase II clinical trials are expected to start in 2010 in four indications for two lead products: ADX48621, an mGluR5 negative allosteric modulator (NAM), in dystonia and Parkinson’s disease levodopa-induced dyskinesia (PD-LID); and ADX71149, an mGluR2 positive allosteric modulator (PAM), in schizophrenia and anxiety. A third product, ADX71943, GABA-B receptor PAM with potential for chronic pain, is scheduled to enter Phase I testing around the end of 2010. In addition, Merck & Co., Inc. has licensed rights to two preclinical products: mGluR4 PAM for Parkinson's disease and mGluR5 PAM for schizophrenia. Additional preclinical discovery stage programs include: mGluR2 NAM, GLP1R PAM, IL1R1 NAM and TNFR1 NAM. Roche Venture Fund and SR-One, corporate venture arm of GlaxoSmithKline, are investors in Addex.

Chris Maggos
Investor Relations & Communications
Addex Pharmaceuticals
+41 22 884 15 11
chris.maggos(at)addexpharma.com

Disclaimer: The foregoing release may contain forward-looking statements that can be identified by terminology such as "not approvable", "continue", "believes", "believe", "will", "remained open to exploring", "would", "could", or similar expressions, or by express or implied discussions regarding Addex Pharmaceuticals Ltd, its business, the potential approval of its products by regulatory authorities, or regarding potential future revenues from such products. Such forward-looking statements reflect the current views of Addex Pharmaceuticals Ltd regarding future events, future economic performance or prospects, and, by their very nature, involve inherent risks and uncertainties, both general and specific, whether known or unknown, and/or any other factor that may materially differ from the plans, objectives, expectations, estimates and intentions expressed or implied in such forward-looking statements. Such may in particular cause actual results with allosteric modulators of mGluR2, mGluR4, mGluR5, mGluR7 or other therapeutic targets to be materially different from any future results, performance or achievements expressed or implied by such statements. There can be no guarantee that allosteric modulators of mGluR2, mGluR4, mGluR5, mGluR7 will be approved for sale in any market or by any regulatory authority. Nor can there be any guarantee that allosteric modulators of mGluR2, mGluR4, mGluR5, mGluR7 or other therapeutic targets will achieve any particular levels of revenue (if any) in the future. In particular, management's expectations regarding allosteric modulators of mGluR2, mGluR4, mGluR5, mGluR7 or other therapeutic targets could be affected by, among other things, unexpected actions by our partners, unexpected regulatory actions or delays or government regulation generally; unexpected clinical trial results, including unexpected new clinical data and unexpected additional analysis of existing clinical data; competition in general; government, industry and general public pricing pressures; the company's ability to obtain or maintain patent or other proprietary intellectual property protection. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those anticipated, believed, estimated or expected. Addex Pharmaceuticals Ltd is providing the information in this press release as of this date and does not undertake any obligation to update any forward-looking statements contained in this press release as a result of new information, future events or otherwise, except as may be required by applicable laws.