Janssen halts Addex epilepsy drug development

Janssen Pharmaceuticals, now known as J&J Innovative Medicine, has decided to discontinue the development of its glutamate mGlu2 receptor in epilepsy, according to its partner, Addex Therapeutics. This decision, following previously reported disappointing top-line phase 2 data, was largely anticipated.

In April, Janssen shared data from a multi-center phase 2 study evaluating the efficacy of ADX71149, an allosteric modulator of the mGlu2 receptor intended to regulate glutamate release in the brain. The study included 110 patients experiencing focal onset seizures who had inadequate responses to standard seizure medications, either levetiracetam or brivaracetam. Unfortunately, the trial did not meet its primary endpoint of achieving statistical significance in reducing the baseline seizure count when ADX71149 was added to the standard treatment regimen.

The collaboration between Janssen and Addex began in 2004. While the development of ADX71149 as an adjunctive treatment for epilepsy has now been halted, the partnership remains active. Both companies are continuing to analyze the complete data set from the phase 2 study. This longstanding partnership allowed Janssen to hold development and commercialization rights for mGlu2 PAM compounds. In return, Addex stood to potentially receive up to $116 million in milestone payments and royalties.

Despite the setback with ADX71149, the companies' ongoing collaboration suggests that there may be future opportunities to explore additional therapeutic avenues or compounds. For now, the focus will likely remain on understanding the full implications of the phase 2 study results and determining any next steps in their joint research efforts.