Addex Drug-Candidate Effective In Alzheimer's Disease Model
Allosteric modulation company Addex Pharmaceuticals Ltd (SIX: ADXN) announced today that it has observed efficacy in a model of Alzheimer's disease using a recently discovered orally-available drug-candidate. The proprietary molecule specifically inhibits a receptor subtype called the metabotropic glutamate receptor 2 (mGluR2) via negative allosteric modulation (NAM). An Addex mGluR2 NAM is scheduled to enter Phase I clinical testing in healthy volunteers during 2011.
"Specifically targeting the signaling of the neurotransmitter glutamate using mGluR2 NAM is one of the most promising avenues of research for treating cognitive symptoms of Alzheimer's disease," said Vincent Mutel, CEO of Addex. "We are excited that our mGluR2 NAM has shown that it can improve memory in this pathophysiologically relevant model. Although we are years away from knowing if the drug will work in humans, recently published academic research suggests that mGluR2 inhibition also may slow the progression of this devastating disease."
The Addex mGluR2 NAM was tested in a model that mimics aspects of the pathophysiology and cognitive impairment, including progressive memory impairment, observed in human Alzheimer's disease. In the preclinical study, the mGluR2 NAM dose-dependently reversed memory deficit exhibited after beta-amyloid protein administration. Working memory impairment was measured using the novel object recognition (NOR) test. The statistically significant effect was similar to the active comparator used in the same experiment, donepezil (Aricept), the benchmark marketed drug currently used to treat symptoms of Alzheimer's disease. Furthermore, the mGluR2 NAM did not change locomotor activity compared to vehicle.
Alzheimer's disease is a progressive brain disease affecting up to 5.3 million Americans and the seventh-leading cause of death in the United States. It destroys brain cells causing memory loss and problems with thinking and behavior. There is no cure and marketed drugs offer temporary moderate efficacy.
mGluR2 is a G-protein coupled receptor (GPCR) that is expressed in the brain on presynaptic nerve terminals where it slows glutamate release. Research has shown that too much signaling by mGluR2 may negatively impact the survival of brain cells involved in memory, contributing to the cause of Alzheimer's disease. Additional research, including the data discussed above, suggests that mGluR2 inhibition can improve working memory, even in cases where memory already has been impaired.
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: GLP1R PAM, IL1R1 NAM and TNFR1 NAM. Roche Venture Fund and SR-One, corporate venture arm of GlaxoSmithKline, are investors in Addex.
SOURCE: Addex Pharmaceuticals