Addex Therapeutics, a leading company pioneering allosteric modulation-based drug discovery and development, has reported positive preclinical data for its GABAB receptor positive allosteric modulator (PAM) oral small molecule in a validated rodent model of chronic alcohol dependence (i.e. alcoholism). The Addex' clinical candidate, ADX71441, demonstrated robust and dose-dependent suppression of alcohol intake in animals lasting 24 hours.

"These data support and expand those obtained previously in a mouse model of binge alcohol drinking with this molecule. Taken together, they offer strong evidence that ADX71441 can be used as a treatment of binge drinking and chronic alcohol dependence," said Professor Klaus Miczek at Tufts University (USA) in whose laboratory the study was performed.

ADX71441 is an oral small molecule, with potential for once daily dosing, which selectively activates GABAB receptor. The compound was evaluated in an intermittent access to alcohol model of chronic alcohol dependence in mice. This procedure generates excessive voluntary alcohol drinking after animals are given 24-hour access to alcohol concomitant to water every other day. In animals with a history of four weeks of excessive drinking, oral ADX71441 (3, 10, 17 mg/kg), administered acutely, resulted in a dose-dependent suppression of alcohol intake, achieving 70 per cent reductions at the higher doses (17 mg/kg) in comparison to vehicle treatment. Significant reductions in alcohol consumption in response to ADX71441 treatment were present for the entire 24-hour alcohol access period. The effect of ADX71441 in this model was more robust and longer-lasting than that seen in mice treated with naltrexone, used in the study as a positive control.  Also, the effect of ADX71441 was characterized with remarkable behavioural specificity since water consumption was not influenced by the treatment.

"These data again support the potential of ADX71441 in a broad range of indications," noted Dr Graham Dixon, CSO at Addex. "We believe that a, once-a-day, well-tolerated, efficacious oral treatment for alcoholism would represent a major advance in the treatment of this devastating condition."

Oral small molecule GABAB receptor PAMs have broad potential in multiple indications and Addex has previously demonstrated positive proof of concept in a range of preclinical models including those of pain, anxiety, obsessive-compulsive disorder and overactive bladder (OAB). Based on ADX71441 current data package, Addex is positioning the drug candidate as a treatment for the rare disease CMT1a, a form of peripheral neuropathy as well as for patients with spasticity, e.g. in multiple sclerosis or spinal cord injury.

"We look forward to initiating the clinical testing for this compound," stated Bharatt Chowrira, PhD., chief executive officer at Addex. "We can see a huge market opportunity for a GABAB PAM in a variety of psychiatric and neurological conditions as well as a potential replacement therapy for baclofen.  We believe we can potentially build sustainable and valuable franchises around both ADX71441 and dipraglurant in that both represent treatments for a wide range of therapeutic indications. We expect to deliver top-line safety, pharmacokinetic and biomarker data on ADX71441 by year end."

Alcoholism is a broad term for problems with alcohol, and is generally indicative of compulsive and uncontrolled consumption of alcoholic beverages. It is medically considered a disease, specifically an addictive illness. The WHO estimates that about 140 million people throughout the world suffer from alcohol dependence. Patients with alcoholism suffer major changes to the brain structure and chemistry. Excessive alcohol consumption damages almost every organ in the body and the cumulative toxic effects can cause both medical (cirrhosis of the liver, pancreatitis, heart disease, peptic ulcers, sexual dysfunction) and psychiatric (epilepsy, dementia, psychosis, anxiety & depression) problems. Treatment of alcoholism is complex with a current standard of care typically being prescribed to patients with heavy drinking but largely being unable to prevent them from relapsing.

Activation of gamma-aminobutyric acid subtype B (GABAB) receptor, a Family C class of GPCR, is clinically and commercially validated by generic GABAB receptor agonist, baclofen, which is marketed for spasticity in spinal cord injury patients. Baclofen has also shown clinical relevance in a number of other indications including overactive bladder, pain and is in early stage clinical development for alcohol dependence and autism. Despite baclofen's broad clinical validation, it is not commonly used due to multiple side effects, rapid clearance and withdrawal syndromes. Orthosteric GABAB receptor agonists have also shown clinical validation in gastroesophageal reflux disease (GERD). Addex' GABAR PAMs have shown efficacy in multiple preclinical models including: OAB, pain, osteoarthritis pain, anxiety and alcoholism.

Addex Therapeutics is focused on advancing innovative oral small molecules against rare diseases utilising its pioneering allosteric modulation-based drug discovery platform.