Addex Therapeutics

Addex Therapeutics, located in Geneva, was founded in 2002 by Vincent Mutel and others when he left Roche (he left Addex in 2011). Addex is focused on finding and developing small molecule drugs which are allosteric and target G-Protein Coupled Receptors, receptor tyrosine kinases and cytokine receptors. Allosteric regulators bind at sites other than the active site of proteins and can both activate or inhibit protein function. To the best of my knowledge (and what they say on the webpage), it is difficult to screen for this kind of interaction.

I can't find very much information about the screens for their allosteric modulators, nothing much comes up in the publications and very little detail is supplied on their webpage. Given that one system looks at a dynamic, direct effect in real-time on the receptor, and that the screen is called ProxyLite, I would hazard a guess in at least one screen they are looking at FRET between two fluorescent proteins or something similar.

They have also developed a compound library which they claim to be biased towards allosteric drugs (as of 2009 it had 70,000 compounds). Addex Therapeutics describes a challenge with developing these drugs is because usually the allosteric binding site is in the transmembrane part of the receptor which requires a type of compound 'greasy' enough to stick to the site, but with good enough (soluble enough) properties to travel in the body to site.

Addex Therapeutics also has several compounds advancing in clinical and preclinical trials, some with their partner Janssen Pharmaceuticals, Inc. Their most advanced has finished phase IIa. They also are part of the ubiquitous CTI, just recently receiving a grant together with EPFL and UNIL to develop allosteric modulator therapeutics for neurodegenerative and psychiatric diseases.

Interestingly, Addex went public in 2007 (IPO on the Swiss stock exchange), that's only 5 years after starting up. Usually in biotech the 'exit strategy' for companies is some kind of M&A, mergers and acquisitions with the goal of being bought out by a large pharma company.