Geneva, Switzerland, 25 August 2010 - Allosteric modulation company Addex Pharmaceuticals Ltd (SIX:ADXN) announced today that the Phase I studies required to commence Phase II testing of ADX71149 have been satisfactorily completed. Subject to regulatory authorizations, Phase IIa studies in schizophrenia and anxiety, are scheduled to start enrolling patients in the first quarter of 2011.

The Phase I program was conducted by Johnson & Johnson Pharmaceutical Research and Development (J&JPRD) on behalf of Ortho-McNeil-Janssen Pharmaceuticals, Inc. (OMJPI) and included more than five studies in normal human volunteers, including: single ascending dose; multiple ascending dose; food & gender; ketamine challenge (a model of psychosis); and anxiety challenge.

In 2005, Addex Pharmaceuticals announced it had entered an exclusive worldwide research collaboration and license agreement with OMJPI to discover, develop and commercialize novel allosteric compounds for the treatment of anxiety, depression, schizophrenia and Alzheimer's disease. The initial drug discovery research was conducted both at Addex and at J&JPRD. Under the terms of the agreement, OMJPI paid Addex a €3 million upfront fee and research funding for 2 years. In addition, Addex is eligible for up to a total of €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 a truly innovative, potentially life changing drug candidate for patients suffering from schizophrenia, anxiety and possibly other disorders,” CEO Vincent Mutel said. “The Phase I program demonstrates that ADX71149 tolerability and safety monitoring parameters were within acceptable limits and support continued study in patients.”

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.

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 regulatory approvals, Phase II clinical trials are expected to start soon 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 in 2011. 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.