AbbVie secures GBP£1.2 billion deal for Gilgamesh’s psychedelic programme

AbbVie has penned a significant agreement to acquire the bretisilocin programme from Gilgamesh Pharmaceuticals for up to £1.2 billion, marking a bold step in the pharmaceutical giant's quest to develop treatments for psychiatric disorders.

The deal structure differs from earlier reports which suggested AbbVie might purchase Gilgamesh outright. Instead, AbbVie will take ownership of the bretisilocin programme whilst allowing Gilgamesh to spin off its other assets into a newly formed entity called Gilgamesh Pharma.

Bretisilocin, also known as GM-2505, is designed to target the 5-HT2A receptor, which plays a central role in the psychedelic response to substances such as LSD and psilocybin. A key advantage of the compound is its shorter half-life compared to traditional psychedelics – approximately 45 minutes – potentially making it more suitable for clinical practice within a two-hour in-clinic framework similar to Johnson & Johnson's ketamine drug Spravato.

The programme has shown promising results, with Gilgamesh reporting a remarkable 94% remission rate in a phase 2 trial involving patients with major depressive disorder. This success likely contributed to AbbVie's interest in securing the asset.

This acquisition extends AbbVie's commitment to the psychedelics space, positioning it as one of the few major pharmaceutical companies actively pursuing this emerging therapeutic area. The cautious approach to the deal structure reflects a measured valuation for the Gilgamesh asset, according to market analysts.

The transaction builds upon an existing relationship between the two companies. In May last year, AbbVie had already inked an option and licensing deal with Gilgamesh, providing GBP£65 million upfront to research and develop next-generation therapies for psychiatric disorders. That agreement, which included up to GBP£1.95 billion in option fees and milestones, will now be transferred to the newly formed Gilgamesh Pharma.

This latest move aligns with AbbVie's broader business development strategy, which has seen the company engage in numerous acquisitions over the past couple of years to strengthen its early-stage pipeline and drive long-term growth, particularly in the neuroscience area.

The acquisition demonstrates AbbVie's continued interest in depression treatments despite experiencing a significant setback last year with the failure of another compound in its portfolio.

Source:

AbbVie tunes in to Gilgamesh's story, inking $1.2B deal for psychedelic program [Accessed August 27, 2025] https://www.fiercebiotech.com/biotech/abbvie-tunes-gilgameshs-story-inking-12b-deal-psychedelic-program