Addex and Sinntaxis Sign Option Agreement for mGlu5 Inhibitors in Brain Injury Recovery

Ad Hoc Announcement Pursuant to Art. 53 LR

Geneva, Switzerland, April 30, 2025 - Addex Therapeutics, a Switzerland-based biopharmaceutical company that is publicly traded on both SIX Swiss Exchange and NASDAQ with the ticker symbol ADXN, has made a significant advancement in the field of neurological treatment. The company disclosed a strategic collaboration and option agreement with Sinntaxis AB, a firm focused on brain injury recovery therapeutics. This partnership gives Addex exclusive access to Sinntaxis' intellectual property concerning the use of metabotropic glutamate receptor subtype 5 (mGlu5) inhibitors, crucial for brain injury rehabilitation efforts.

The collaboration centers around Addex’s leading drug candidate, dipraglurant, which is an oral mGlu5 negative allosteric modulator. Sinntaxis will lead the preclinical evaluation of dipraglurant, aimed at enhancing recovery from brain injuries, such as those caused by strokes or trauma. Addex has previously demonstrated dipraglurant's safety, tolerance, and high selectivity for the mGlu5 receptor in other clinical studies, suggesting its potential effectiveness in aiding functional recovery for patients with neurological impairments.

Tim Dyer, CEO of Addex, emphasized the strategic importance of this collaboration. He noted that repositioning dipraglurant towards addressing unmet medical needs in brain injury recovery aligns with Addex’s long-term goals. The preclinical studies conducted by Sinntaxis will build upon previously published data, helping to validate dipraglurant's efficacy in neurological recovery contexts.

The agreement entails Addex paying an undisclosed option fee to Sinntaxis, giving them exclusive licensing rights over the intellectual property surrounding mGlu5 inhibitors used in treating brain injuries. Additionally, Sinntaxis is tasked with executing a comprehensive research plan to complete preclinical evaluations, leveraging their expertise in designing effective clinical approaches.

Tadeusz Wieloch, CEO of Sinntaxis, expressed optimism about the collaboration, highlighting the mGlu5 receptor’s role in brain plasticity and function modulation. He conveyed that Sinntaxis is eager to contribute their expertise to accelerate the clinical trial phase for dipraglurant, with the shared goal of enhancing recovery outcomes for brain injury patients.

The broader scientific community has recognized the potential of mGlu5 negative allosteric modulators (NAMs) in facilitating recovery post-stroke. Research suggests these modulators aid in forming new neural connections or reactivating existing ones. A study published in the journal "BRAIN" demonstrated that mGlu5 NAMs administered for 12 days post-stroke restored sensory functions without affecting infarct size. Recovery in sensory-motor functions was noted quickly after treatment began, with improvements continuing over the treatment period. Furthermore, mGlu5 inhibition helped reverse disruptions in brain connectivity after a stroke.

Addex Therapeutics, beyond its current collaboration focus, continues to develop a diverse pipeline of allosteric modulators for various neurological disorders. Among its ventures, Addex is partnering with Indivior to develop a GABAB positive allosteric modulator (PAM) for substance use disorders, and independently advancing a GABAB PAM program for chronic cough. Additionally, Addex holds a significant stake in Neurosterix LLC, which is developing modulators addressing schizophrenia, mood disorders, and mild neurocognitive disorders.

Overall, this collaboration between Addex and Sinntaxis appears set to advance innovative treatments in the realm of neurological recovery, potentially offering new hope and improved outcomes for patients affected by serious brain injuries.