Addex: ADX71943 Demonstrates Analgesic Effects in Pain Models

Geneva, Switzerland – Addex Pharmaceuticals (SIX:ADXN), the allosteric modulation company, announced today that ADX71943 has demonstrated statistically significant analgesic-like effects in three preclinical models of pain.

In the first model, ADX71943 reversed complete Freund adjuvant (CFA)–induced reductions in withdrawal thresholds in a dose-related manner, with a minimum statistically significant effective oral dose of 10 mg/kg. In a second model (Formalin test), ADX71943 showed anti-nociceptive effect after oral administration of 3 to 10 mg/kg. In a third model, an increased visceral pain threshold was seen using ADX71943 with a minimum statistically significant effective dose between 3 and 10 mg/kg.

ADX71943 is an orally available positive allosteric modulator (PAM) of the GABA(B) receptor that has potential for treatment of osteoarthritis pain and chronic nociceptive pain as well as other indications. ADX71943 has a good developability profile and is expected to enter clinical testing in the fourth quarter 2010.

“We are impressed with the profile of the compound and by its activity in these models. Furthermore,
minimum effective doses observed in the preclinical models and the pharmacokinetic properties of the compound support prediction of treatment regimens in humans compatible with the target patient population and disease” said Sonia Poli, head of non-clinical development at Addex.

GABA(B) activation is a clinically validated mechanism. Baclofen, a GABA(B) agonist, is widely used for its muscle relaxant properties in the control of spasticity caused by multiple sclerosis, cerebral palsy or certain injuries to the spine. Furthermore, Baclofen is a powerful analgesic agent, especially when delivered intrathecally. However, rapid induction of tolerance and dose limiting CNS-mediated side effects (e.g. sedation, hypothermia, memory impairment) prevent baclofen from being widely prescribed for pain relief despite its analgesic properties. ADX71943, an allosteric modulator with a differentiated profile, could avoid the tolerance and dose limiting side effects commonly associated with baclofen.

Osteoarthritis (OA) is a widespread condition affecting the elderly population in particular. One of the most debilitating symptoms is chronic pain associated with OA. Patients suffering from chronic pain will require treatment over the long-term. There is a clear need for drugs with better side effect profiles than current marketed drugs (e.g. non-steroidal anti-inflammatory drugs and opioids).

Addex Pharmaceuticals (www.addexpharma.com) utilizes its unique proprietary platform technologies to discover and develop allosteric modulators for human health. Allosteric modulators are a different kind of orally available small molecule therapeutic agent, which we believe will offer a competitive advantage over classical drugs. With 15 programs in development, the Addex pipeline demonstrates the productivity and broad potential of our unparalleled platform technologies. The most advanced product, ADX48621, an mGluR5 negative allosteric modulator (NAM), has completed Phase I testing and is scheduled to start Phase II testing for Parkinson’s disease levodopa associated dyskinesia (PD-LID) later in 2010.

Our products and technology already have proven their value through our relationships with four of the top 10 pharmaceutical companies in the world. Specifically, under an agreement with Ortho-McNeil-Janssen Inc., a Johnson & Johnson company, ADX71149, an mGluR2 positive allosteric modulator (PAM), is undergoing Phase I clinical testing and has potential for treatment of schizophrenia and anxiety. Under two separate agreements with Merck & Co., Inc., we are developing PAMs of mGluR4 and mGluR5 as drugs to treat Parkinson’s disease and schizophrenia, respectively. In addition, SR-One, the corporate venture arm of GlaxoSmithKline, and Roche Venture Fund have made equity investments in Addex.

Disclaimer: The foregoing release contains 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, and involve known and unknown risks, uncertainties and other factors that may cause actual results with allosteric modulators of mGluR4, mGluR2, mGluR5 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 mGluR4, mGluR2 or mGluR5 will be approved for sale in any market or by any regulatory authority. Nor can there be any guarantee that allosteric modulators of mGluR4, mGluR2, mGluR5 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 mGluR4, mGluR2, mGluR5 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 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.