Addex Therapeutics announced top-line data from a Phase 2 epilepsy study evaluating adjunctive ADX71149 (JNJ-40411813) administration in patients with focal onset seizures with suboptimal response to levetiracetam or brivaracetam. The Phase 2 study 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. The data were reported from a total of 110 evaluable patients, who each received either 50 mg or 100 mg of ADX71149 twice daily (100 mg or 200mg twice daily, respectively, for patients receiving CYP3A4 inducing anti-seizure medication) in addition to their standard dose of levetiracetam or brivaracetam and up to three other anti-seizure drugs.

Adjunctive administration of ADX71149 was safe and well tolerated. 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.