Indivior ends Addex PAM collaboration as it prepares for Supernus merger

Indivior Pharmaceuticals has terminated its long‑standing partnership with Addex Therapeutics that focused on developing positive allosteric modulators (PAMs) for addiction treatment.

The collaboration began in 2018 when Indivior paid an upfront $5 million to work on a PAM candidate, ADX71441. That program was later discontinued, but the companies later extended the deal in August 2024 to pursue another PAM candidate.

As Indivior moves toward the planned merger of its parent company with Supernus, it is rationalizing its R&D pipeline and has returned all PAM assets to Addex. Addex’s CEO said the regained rights expand its portfolio targeting the GABAB receptor.

The termination does not affect other ongoing activities between the two firms, but it reflects Indivior’s focus on streamlining its pipeline ahead of the merger.