J&J drops Addex-partnered epilepsy drug after reviewing failed phase 2 trial data

After mulling over the data from a failed phase 2 trial, Johnson & Johnson has decided to halt development of its Addex Therapeutics-partnered epilepsy drug, Fierce Biotech has learned.

The positive allosteric modulator (PAM) of metabotropic glutamate receptor-2, dubbed ADX71149, emerged from a 2004 collaboration between Addex and J&J’s Janssen unit. Janssen oversaw a mid-stage trial of 110 evaluable patients whose focal onset seizures had not been adequately controlled by the approved epilepsy meds levetiracetam or brivaracetam.

But Addex revealed in late April that the study had failed to demonstrate a delay in the time it took for patients to reach their baseline seizure count, missing the trial’s primary endpoint.

In a June 6 earnings call, Addex CEO Tim Dyer told analysts that Janssen was in the process of undertaking an analysis of the full data from the trial before making a decision on whether to continue its involvement.

“Clearly one option, which is reasonably possible, is that the collaboration gets terminated and Addex receives back the molecule and all the backup molecules as well,” Dyer said on the call. “But until we see the full dataset, we can’t really full understand whether there is a way forward in epilepsy or not.”

When J&J came to announce its own earnings yesterday, ADX71149—also known as JNJ-40411813—was notably absent from the Big Pharma’s updated pipeline. The company confirmed to Fierce Biotech via email that it had notified Addex that it had decided to discontinue development of the molecule as a treatment for epilepsy.

“We have been working closely with trial sites to inform enrolled patients so they may seek alternative treatment options,” a J&J spokesperson added.

The spokesperson later clarified that the decision to end work on ADX71149 “does not affect our partnership and collaboration with Addex.” 

Fierce Biotech has asked Addex whether it has plans to continue developing ADX71149 as an epilepsy therapy by itself. The Geneva-based company has two other clinical-stage assets in the works, headed up by a mGlu5 negative allosteric modulator called dipraglurant.

Dipraglurant has had its own struggles in the clinic, with the company revealing in 2022 that a phase 2 trial designed to spearhead its expansion into muscle spasm disorders had delivered “inconclusive” data. A Parkinson’s study was planned, but COVID-19 headwinds soon blew that off course as well.

CEO Dyer explained to Fierce last year how persuading investors about the potential of the Janssen collaboration for ADX71149 helped steady the ship during this stormy moment.

Addex is now evaluating dipraglurant as a potential treatment for dyskinesia associated with Parkinson’s and post-stroke/traumatic brain injury recovery.

This article was updated at 2.55 pm ET on July 18 to include an additional statement sent by J&J on the state of the Addex partnership.