AbbVie announced a definitive agreement to acquire Gilgamesh Pharmaceuticals’ leading investigational drug candidate, currently in clinical trials for treating moderate-to-severe major depressive disorder (MDD). This development signifies a strategic move in the pursuit of innovative mental health treatments.
The focus is on psychedelics, particularly 5-HT2A receptor agonists, which have shown promise due to their rapid and sustained antidepressant effects. However, existing drugs in this category often cause prolonged psychoactive experiences, limiting their practicality.
Gilgamesh’s novel compound, bretisilocin, is designed to address these challenges. It is a next-generation psychedelic that functions as a 5-HT2A receptor agonist and 5-HT releaser, with a shorter duration of psychoactive effects while maintaining extended therapeutic benefits. Recent topline results from a Phase 2a study of bretisilocin in MDD showed significant improvements in depression severity.
A single 10mg dose led to a notable reduction in MADRS scores—21.6 points from baseline—by day 14, compared to a 12.1-point reduction observed with a 1mg low dose. The results were statistically significant, and the drug was well tolerated, with no serious adverse events reported.
Under the terms of the agreement, AbbVie will pay up to $1.2 billion, including upfront and milestone payments, to acquire the bretisilocin program. Additionally, Gilgamesh will spin off a new entity, Gilgamesh Pharma, which will hold its employees, other drug programs—including an oral NMDA receptor antagonist, blixeprodil—and existing collaborations. This transaction builds upon a prior partnership between the companies, which included an option-to-license agreement for the development of new psychiatric therapies. That agreement will now be transferred to Gilgamesh Pharma Inc., allowing them to continue their collaborative efforts.
Advisors: For AbbVie, Covington & Burling is acting as legal counsel. For Gilgamesh, Centerview Partners is acting as exclusive financial advisor and Ropes & Gray is acting as legal counsel.
KEY QUOTES:
“The field of psychiatry represents one of the most challenging areas in medicine, with a significant need for innovative solutions. This acquisition underscores our commitment to broadening and enhancing psychiatric care by investing in novel treatment approaches with the potential to reach patients for whom other treatments have been ineffective. We look forward to advancing bretisilocin to late-stage clinical development.”
Roopal Thakkar, M.D., executive vice president, research and development and chief scientific officer, AbbVie
“AbbVie’s leadership in neuroscience and commitment to advancing innovative treatments make them the ideal partner to advance bretisilocin rapidly forward while enabling Gilgamesh to continue pursuing our broader mission of developing novel, transformative therapies for complex mental health and neurological conditions.”
Jonathan Sporn, M.D., chief executive officer at Gilgamesh Pharmaceuticals
