Addex’s Partner Discontinues ADX71149 development in Epilepsy

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Addex Therapeutics
Addex Therapeutics

Ad Hoc Announcement Pursuant to Art. 53 LR

Geneva, Switzerland, July 22, 2024 - Addex Therapeutics (SIX and Nasdaq: ADXN), a clinical-stage biopharmaceutical company focused on developing a portfolio of novel small molecule allosteric modulators for neurological disorders, announced today that its partner Janssen Pharmaceuticals, Inc. (now known as J&J Innovative Medicine) has informed the company that it has discontinued development of ADX71149 (JNJ-40411813) in epilepsy. The partnership between the two companies remains ongoing while the full data set from the Phase 2 study of ADX71149 (JNJ-40411813) as an adjunctive epilepsy treatment is analyzed.

The decision follows top-line Phase 2 data announced on April 29, 2024, showing that adjunctive ADX71149 (JNJ-40411813) administration in patients with focal onset seizures with suboptimal response to levetiracetam or brivaracetam did not achieve statistical significance for the primary endpoint of time for patients to reach baseline seizure count when ADX71149 was added to standard of care.

“Following the Phase 2 study results in epilepsy, this decision was anticipated. We have had an excellent working relationship with Janssen for twenty years and will continue to work diligently to complete the analysis of the full Phase 2 data set to elucidate all learnings from the study,” said Tim Dyer, CEO of Addex. “Once we have that information in hand, we anticipate a decision on the future of this asset.”

About the Study:
ADX71149 is a selective metabotropic glutamate subtype 2 (mGlu2) receptor positive allosteric modulator (PAM). The multi-center Phase 2 study was designed to assess the efficacy, safety, tolerability, and pharmacokinetics of adjunctive ADX71149 administration in patients with focal onset seizures with suboptimal response to levetiracetam or brivaracetam. The primary objective of the study was to evaluate the efficacy of ADX71149 in combination with levetiracetam or brivaracetam using a time to baseline seizure count endpoint. Part 1 of the study evaluated the acute efficacy of ADX71149 over 4 weeks. Patients who did not reach their monthly baseline seizure count in Part 1 continued double-blind treatment during Part 2 until they reached their monthly baseline seizure count or 8 weeks, deemed the maintenance efficacy phase. More information on the study can be found with Clinicaltrials.gov identifier NCT04836559.

About Glutamate mGlu2 Receptors and Epilepsy:
Glutamate is the primary excitatory neurotransmitter in the brain and plays a key role in the initiation and spread of seizures. When activated, the mGlu2 receptor decreases the release of glutamate and consequently, helps to maintain neurotransmitter balance. In the presence of agonist-induced activation, positive allosteric modulation of mGlu2 receptors could result in the normalization of the excessive glutamate release seen during a seizure. Epilepsy remains a challenging unmet medical need, with a significant proportion of the patient population struggling in their day-to-day management of seizures.