AbbVie has reached a definitive agreement to acquire Gilgamesh Pharmaceuticals’ lead investigational therapy, bretisilocin, for the treatment of moderate-to-severe major depressive disorder (MDD). According to the company, results from a recent Phase IIa trial showed that a single 10 mg dose of bretisilocin produced a robust reduction in depressive symptoms compared with a low-dose active comparator.

How will AbbVie Structure the Deal and Support Gilgamesh’s Remaining Programs?

Under terms of the deal, AbbVie will pay up to $1.2 billion for the program, including upfront and milestone payments. As part of the transaction, Gilgamesh will spin out a new entity, Gilgamesh Pharma Inc., to retain its remaining programs—including an oral NMDA receptor antagonist, a cardio-safe ibogaine analog, and an M1/M4 agonist program—while maintaining its existing collaboration and option-to-license agreement with AbbVie.¹

"The field of psychiatry represents one of the most challenging areas in medicine, with a significant need for innovative solutions," said Roopal Thakkar, MD, EVP, research and development, chief scientific officer, AbbVie, in a press release. "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."

AbbVie’s US Manufacturing Investments

The deal comes shortly after AbbVie made a major investment in US manufacturing. On August 13, 2025, the company announced a $195 million investment to expand active pharmaceutical ingredient manufacturing at its North Chicago, Ill., facility.

Construction of the facility is expected to begin later this year, with operations slated to commence by 2027. AbbVie stated that the new facility will expand its US manufacturing network of 11 sites and 6,000 employees, while also creating additional jobs through nationwide supplier partnerships.²

Recent Strategic Moves Highlight AbbVie’s Aggressive Portfolio Expansion

AbbVie has made a series of recent high-profile acquisitions and strategic partnerships this year, as the company makes an aggressive push to expand its pipeline and diversify its portfolio.

• In June, AbbVie announced that it had acquired Capstan Therapeutics for approximately $2.1 billion in cash at closing. The deal included CPTX2309, an anti-CD19 CAR T-cell therapy, which is currently in development for B cell-mediated autoimmune diseases.³
• In March, the company announced that it had agreed to terms on a deal with Gubra to develop GUB014295, a weight loss treatment designed to help people manage weight by controlling their appetite. Under terms of the deal, AbbVie will oversee development and global commercialization, while Gubra received $350 million in upfront payments, and could earn up to $1.875 billion more through milestone-based payments.⁴
• In January, AbbVie agreed to a deal with Neomorph aimed at co-developing molecular glue degraders to target proteins that are considered to be undruggable. Neomorph could earn up to $1.64 billion in aggregate option fees and milestones, as well as tiered royalties on net sales.⁵
• Also in January, AbbVie announced a license agreement with Simcere Zaiming to develop SIM0500 for patients with relapsed or refractory multiple myeloma. Simcere Zaiming has the potential to receive up to $1.055 billion in option fees and milestone payments.⁶

"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," said Jonathan Sporn, MD, CEO, Gilgamesh Pharmaceuticals, in the press release.

References

1. AbbVie to Acquire Gilgamesh Pharmaceuticals' Bretisilocin, a Novel, Investigational Therapy for Major Depressive Disorder, Expanding Psychiatry Pipeline. PR Newswire. August 25, 2025. Accessed August 25, 2025. https://prnmedia.prnewswire.com/news-releases/abbvie-to-acquire-gilgamesh-pharmaceuticals-bretisilocin-a-novel-investigational-therapy-for-major-depressive-disorder-expanding-psychiatry-pipeline-302537266.html
2. AbbVie Latest to Commit to New US Manufacturing Growth Projects, Committing $195 Million to Expand API Capabilities. PharmExec. August 13, 2025. Accessed August 25, 2025. https://www.pharmexec.com/view/abbvie-latest-commit-new-us-manufacturing-growth-projects-committing-195-million-expand-api-capabilities
3. AbbVie Acquires Capstan Therapeutics in $2.1 Billion Deal. PharmExec. June 30, 2025. Accessed August 25, 2025. https://www.pharmexec.com/view/abbvie-acquires-capstan-therapeutics-2-1-billion-deal
4. AbbVie, Gubra Strike Deal to Develop Novel Weight Loss Treatment. PharmExec. March 3, 2025. Accessed August 25, 2025. https://www.pharmexec.com/view/abbvie-gubra-strike-deal-develop-novel-weight-loss-treatment
5. AbbVie, Neomorph Strike Deal to Co-Develop Molecular Glue Degraders for Oncology, Immunology. PharmExec. January 24, 2025. Accessed August 25, 2025. https://www.pharmexec.com/view/abbvie-neomorph-strike-deal-co-develop-molecular-glue-degraders-oncology-immunology
6. Flurry of Acquisitions and Licensing Deals Come Amid JP Morgan Healthcare Conference 2025. PharmExec. January 13, 2025. Accessed August 25, 2025. https://www.pharmexec.com/view/flurry-acquisitions-licensing-deals-come-amid-jp-morgan-healthcare-conference-2025