Addex Therapeutics Ltd, a leading company pioneering allosteric modulation-based drug discovery and development, and its partner Janssen Research & Development, LLC, on behalf of Janssen Pharmaceuticals, Inc., has started a multicentre, double-blind, phase II study of ADX71149 in adults with major depressive disorder (MDD) who are also suffering anxiety symptoms.

ADX71149 is a positive allosteric modulator (PAM) of metabotropic glutamate receptor 2 (mGluR2), a Family C class of G Protein Coupled Receptor (GPCR) that is being jointly developed by Addex and Janssen Pharmaceuticals, Inc., formerly known as Ortho-McNeil-Janssen Pharmaceuticals, Inc. ADX71149 is also being studied in a phase II clinical trial for the treatment of positive and negative symptoms of schizophrenia.

“The initiation of this second phase II study is an indication of the potential for ADX71149 to treat more than one psychiatric disorder. We are delighted by our partner Janssen's continued commitment towards advancing ADX71149 in multiple indications,” noted Bharatt Chowrira, CEO of Addex Therapeutics. “There has been little innovation recently in the way that patients with both depression and anxiety are treated. This provides a significant medical and market opportunity for an innovative approach such as ADX71149 for treating this important psychiatric condition.”

The multicentre, double-blind, placebo-controlled study to evaluate the efficacy and overall safety and tolerability of ADX71149  (Clinicaltrials.gov ref NCT01582815) will be conducted as an adjunctive treatment to an antidepressant in 94 adults with major depressive disorder with anxiety symptoms. Oral ADX71149 will be administered twice-daily at doses ranging from 25mg to 150mg. Patients will continue to take the same daily dose of their antidepressant. The primary endpoint of the study is the change from baseline in the Hamilton Anxiety Rating scale (HAM-A6) score. Secondary endpoints include change from baseline of several other clinician-administered rating scales designed to assess the severity of depression and anxiety symptoms.

The development of ADX71149 is part of a worldwide research collaboration and license agreement between Addex and Janssen Pharmaceuticals, Inc. to discover, develop and commercialize a novel mGluR2 PAM medication for the treatment of anxiety, schizophrenia and other undisclosed indications. Under the terms of the agreement, Addex is eligible for up to a total of €112 million in milestone payments based on potential development and regulatory achievements. In addition, Addex is eligible for low double-digit royalties on sales of any mGluR2 PAM medication developed under the agreement.

Addex Therapeutics discovers and develops an emerging class of small molecule drugs, called allosteric modulators, which have the potential to be more specific and confer significant therapeutic advantages over conventional "orthosteric" small molecule or biological drugs.