Ahead of its upcoming merger with Supernus, Indivior Pharmaceuticals has ended its long-running collaboration with Addex Therapeutics to develop positive allosteric modulators (PAMs).
Their relationship dates back to 2018, when Indivior paid Addex $5 million upfront to collaborate on a PAM called ADX71441 for the treatment of addiction. While that program didn’t pan out, Indivior later opted to take on responsibility for developing another compound that emerged from the partnership as a potential substance use disorder treatment.
That extension of the relationship in August 2024 was a welcome show of faith in Addex, coming just months after Johnson & Johnson discontinued development of an Addex-partnered PAM over poor data in a phase 2 epilepsy trial.
Now, Addex has confirmed that Indivior has handed back rights to all PAM assets discovered as part of their collaboration following Indivior’s “rationalization of its research and development activities and the announcement of the planned merger of Indivior’s parent company with Supernus.”
Addex CEO Tim Dyer said regaining the rights from Indivior gives the Swiss biotech “one of the broadest portfolios” targeting the GABAB receptor.
“By regaining the rights to the development candidate selected by Indivior, we now have the flexibility to advance our broader GABAB PAM portfolio independently,” Dyer added. “This includes the returned candidate for substance use disorders and our proprietary candidate in development for chronic cough.”
“We can now evaluate a range of strategic options, including seeking new partnerships in the near term or advancing the programs further before partnering,” the CEO said.
Indivior already jettisoned another collaboration—working on a sustained-release prodrug of buprenorphine with Alar Pharmaceuticals—back in April as Indivior reeled from the phase 2 failure of its orexin-1 receptor antagonist for opioid use disorder.
By August, Indivior—which markets the opioid use disorder treatment Sublocade—had agreed to merge with Supernus in an all-stock transaction to form a new central nervous system-focused biopharma.