A Major Move in Neuroscience
AbbVie has reached an agreement to acquire the psychedelic drug candidate bretisilocin from Gilgamesh Pharmaceuticals in a deal valued at up to $1.2 billion. The transaction reflects AbbVie’s continued focus on expanding its neuroscience pipeline, particularly in the treatment of psychiatric disorders.
Deal Structure and Spin-Off
The deal differs from earlier reports that suggested AbbVie was exploring a full buyout of Gilgamesh. Instead, AbbVie will take over the bretisilocin program, while Gilgamesh will spin out its other assets into a newly formed company called Gilgamesh Pharma Inc. This new entity will retain Gilgamesh’s employees, pipeline programs, and an existing collaboration with AbbVie.
AbbVie’s financial commitment includes both upfront and development milestone payments, though the specific breakdown has not been disclosed. The companies also noted that no regulatory or commercial milestones or royalties are part of the arrangement.
About Bretisilocin (GM-2505)
The acquisition gives AbbVie rights to bretisilocin, also known as GM-2505, which recently demonstrated promising results in a Phase II trial for major depressive disorder (MDD). In the study, 40 patients received two doses of the drug, spaced about two weeks apart, with a 94% remission rate observed nearly a month after the first dose. The compound is designed to act on the 5-HT2A receptor, a key pathway in the psychedelic response associated with substances such as LSD and psilocybin.
Unlike traditional psychedelics, bretisilocin has a shorter half-life, which could allow administration within a two-hour in-clinic treatment framework. Johnson & Johnson previously introduced this approach for its esketamine-based drug, Spravato.
Strategic Fit for AbbVie
At AbbVie, bretisilocin will join a neuroscience portfolio that includes the antipsychotic Vraylar, developed in partnership with Gedeon Richter, as well as migraine treatments Ubrelvy and Qulipta. The company is also seeking to recover value from its $8.7 billion acquisition of Cerevel Therapeutics, despite setbacks in Phase II trials for emraclidine, a schizophrenia treatment.
By pursuing bretisilocin, AbbVie is re-entering the depression treatment space following the failure of emraclidine last year.
The Future of Gilgamesh
For Gilgamesh, the transaction brings large-scale pharmaceutical backing to its lead program while providing resources for other early-stage projects. These include an oral NMDA receptor antagonist called blixeprodil, an ibogaine analog, and an M1/M4 agonist program. AbbVie will retain an option to license assets from Gilgamesh Pharma under the terms of its original 2024 partnership.
Industry Implications and Analyst Commentary
Industry analysts noted the deal’s implications for the broader psychedelics space. BMO Capital Markets analysts said, “We believe the lower deal value could reflect conservatism around psychedelic valuations in light of the regulatory backdrop for compounds, making today’s deal a well-balanced risk/reward acquisition for the company.”
They also emphasized that the transaction highlights growing pharmaceutical interest in psychedelics for therapeutic use.
Additional commentary came from Gerard Sanacora, professor of psychiatry at Yale University and director of the Yale Depression Research Program, who remarked that the treatment “fits nicely in the two-hour in-clinic framework established by esketamine, but with the potential for significantly fewer annual visits.”
