Addex Announces ADX71149 Phase 2 Epilepsy Clinical Study’s Independent Interim Review Committee Recommends Continuing Study

In This Article:

Addex Therapeutics
Addex Therapeutics
  • Cohort 1 progressing through Part 2

  • Cohort 2 recruiting patients

Ad Hoc Announcement Pursuant to Art. 53 LR

Geneva, Switzerland, May 10, 2023 - Addex Therapeutics (SIX and Nasdaq: ADXN), a clinical-stage pharmaceutical company pioneering allosteric modulation-based drug discovery and development, today announced that the ADX71149 (JNJ-40411813) Phase 2 epilepsy clinical study has been recommended to continue by an Independent Interim Review Committee (IRC) following review of unblinded data from Part 1 of patient Cohort 1. The clinical study is being conducted by Janssen Pharmaceuticals, Inc., one of the Janssen Pharmaceutical Companies of Johnson & Johnson.

“The recommendation of the IRC and the decision of our collaboration partner to continue the study is very encouraging and suggests ADX71149 is potentially safe and well tolerated and may have a positive impact on this patient population,” said Tim Dyer, CEO of Addex. “We look forward to providing further updates on the progression of this important clinical study in the second half of this year.”

ADX71149 is a selective metabotropic glutamate sub-type 2 (mGlu2) receptor positive allosteric modulator (PAM). The multi-center Phase 2 study has been 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. Up to 3 doses (low, medium, high) of ADX71149 in up to 160 patients will be evaluated. The primary objective of the study is 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 evaluates the acute efficacy of ADX71149 over 4 weeks. Subjects who do not reach or exceed their monthly baseline seizure count in Part 1 continue double-blind treatment during Part 2 until they reach their monthly baseline seizure count or 8 weeks, deemed the maintenance efficacy phase. Cohort 1 has completed Part 1 and is currently in Part 2. Cohort 2 has started to recruit patients in Part 1. In addition, patients who complete Part 1 and/or Part 2 of the study have the option to continue treatment in the open-label extension part of the study, which evaluates the long-term efficacy and safety of ADX71149 for up to 2 years. More information on the study can be found with Clinicaltrials.gov identifier NCT04836559.

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. There is still an urgent need for more effective treatments for epilepsy, with improved tolerability and safety. ADX71149 was described in the Eilat 15 conference summary review as a promising novel approach currently in development (Bialer et al., 2020. Epilepsia). Proof of concept data with ADX71149 and other mGlu2 PAMs in animal models of epilepsy have been published in peer-reviewed journals (Metcalf et al., 2017 and 2018. Epilepsia).