Addex Therapeutics
Ad Hoc Announcement Pursuant to Art. 53 LR
Geneva, Switzerland, September 25, 2026 - Addex Therapeutics (SIX: ADXN and Nasdaq: ADXN), a clinical-stage biopharmaceutical company developing novel small molecule allosteric modulators for neurological disorders, today announced that it has regained full global rights to all GABAB positive allosteric modulator (PAM) assets discovered under its research collaboration with Indivior UK Limited ("Indivior"). The return of the rights follows Indivior's rationalization of its research and development activities and the announcement of the planned merger of Indivior's parent company with Supernus Pharmaceuticals, Inc.
"These GABAB PAM assets reflect years of world-class research in allosteric modulation and build on a biological approach clinically validated by baclofen," said Tim Dyer, CEO of Addex Therapeutics. "By regaining the rights to the development candidate selected by Indivior, we now have the flexibility to advance our broader GABAB PAM portfolio independently. This includes the returned candidate for substance use disorders and our proprietary candidate in development for chronic cough. We can now evaluate a range of strategic options, including seeking new partnerships in the near term or advancing the programs further before partnering."
The termination of the collaboration with Indivior provides Addex with full ownership of the returned development candidate and the freedom to pursue therapeutic indications beyond those originally contemplated under the agreement. Combined with Addex's wholly owned GABAB PAM program for chronic cough, the returned asset gives the company one of the broadest portfolios targeting GABAB receptor biology. The portfolio may have potential applications across substance use disorders, chronic cough, pain, overactive bladder, neurodevelopmental disorders, and other conditions in which modulation of GABAB signaling has demonstrated therapeutic promise.
About GABAB activation
GABA is the main inhibitory neurotransmitter in the central and peripheral nervous systems and acts through two major receptor classes: the ionotropic GABAA receptor and the metabotropic GABAB receptor. GABAB receptors are widely expressed throughout the nervous system and play an important role in regulating neuronal excitability and neurotransmission.
The therapeutic potential of GABAB receptor activation has been clinically demonstrated with baclofen, a selective GABAB receptor agonist that binds to the orthosteric GABA binding site. Baclofen is approved for the treatment of spasticity, including spasticity associated with multiple sclerosis and spinal cord injury. It has also been clinically investigated and used off-label across a broader range of neurological, neuropsychiatric disorders and other conditions including alcohol use disorder and alcohol withdrawal, cocaine use disorder, gastroesophageal reflux disease, and reflux-associated chronic cough.