Gilgamesh Pharmaceuticals, Inc.·AbbVie Inc.

Structure

FY2025 Form 10-K (filed 2026-02-20), Note 5 Licensing, Acquisitions and Other Arrangements, p. 67: 'In October 2025, AbbVie completed its previously announced acquisition of Gilgamesh Pharmaceuticals, Inc. (Gilgamesh), including its lead program bretisilocin (GM-2505). GM-2505, renamed ABBV-2505'; 'AbbVie made an upfront cash payment of $906 million to acquire all outstanding equity of Gilgamesh and the transaction was accounted for as an asset acquisition as the lead program represented substantially all of the fair value of the gross assets acquired. The upfront cash payment was recorded in acquired IPR&D and milestones expense in the consolidated statement of earnings in the fourth quarter of 2025. AbbVie could make additional payments of up to $300 million upon achievement of development milestones.' AbbVie release 2025-08-25 (https://news.abbvie.com/2025-08-25-AbbVie-to-Acquire-Gilgamesh-Pharmaceuticals-Bretisilocin,-a-Novel,-Investigational-Therapy-for-Major-Depressive-Disorder,-Expanding-Psychiatry-Pipeline): 'AbbVie will acquire Gilgamesh's bretisilocin program for up to $1.2 billion, inclusive of an upfront payment and development milestones'; Gilgamesh spins off Gilgamesh Pharma Inc. holding 'its employees and other programs, including its oral NMDA receptor antagonist blixeprodil (GM-1020), cardio-safe ibogaine analog, M1/M4 agonist program and existing collaboration with AbbVie'. AbbVie release 2025-10-17 (https://news.abbvie.com/2025-10-17-AbbVie-Completes-Acquisition-of-Gilgamesh-Pharmaceuticals-Bretisilocin) announces completion; close_date is that release date, the 10-K gives October 2025 without a day. total_headline_usd_m 1206 is 906 + 300, arithmetic; AbbVie's published headline is 'up to $1.2 billion'. The 2024 option-to-license agreement is a separate transaction, D004. Changes from the row verified 2026-08-26: upfront 900 to 906 (Q3 2025 10-Q said 'approximately $900 million'); date 2025-10-01 to 2025-08-25 (announcement); close_date 2025-10-01 to 2025-10-17 (the prior value was an XBRL context date). Supersedes the row verified 2026-08-26.

Why it matters

Large pharma buying a psychedelic outright, a year before Lilly. The 10-Q describes GM-2505 as a short-acting 5-HT2A receptor agonist and 5-HT releaser, which is a company-filed mechanism statement and rare in this field. Bretisilocin is also the compound that entered the EMA PRIME scheme in March 2026, making it the one asset in this file with a live European regulatory track.

In the briefing

• 2026-09-22No. 15

  The CVR is an option, and Lilly holds it

  • DEALS
  • REGULATORY
  • TRIALS
  • LILLY
  • ATAIBECKLEY
  • COMPASS
  • ABBVIE
  • OTSUKA