Developer · United States
Gilgamesh Pharmaceuticals, Inc.
Gilgamesh Pharmaceuticals is a privately held, clinical-stage neuroscience biotech (founded 2019, headquartered in New York City) developing novel chemical entities, including next-generation psychedelics and neuroplastogens, for psychiatric disorders such as major depressive disorder. Following AbbVie's August 2025 acquisition of its lead bretisilocin (GM-2505) program, its remaining programs are held by a spinoff operating as Gilgamesh Pharma Inc.
2compounds
2programs
1indication
Phase 2lead asset
Pipeline (2)
- Major depressive disorderPhase 2Completed
- Major depressive disorderPhase 2Recruiting
Deals & partnerships
- Blixeprodil (GM-1020)Partner AbbVie Inc.
- Bretisilocin (GM-2505)Partner AbbVie Inc.Licensee AbbVie Inc.
- Aug 25, 2025AcquisitionAbbVie to acquire Gilgamesh's bretisilocin (GM-2505) programAbbVie announced a definitive agreement to acquire Gilgamesh's lead investigational candidate bretisilocin (GM-2505), a short-acting 5-HT2A agonist/5-HT releaser in Phase 2 for moderate-to-severe major depressive disorder, for up to $1.2 billion inclusive of an upfront payment and development milestones. The deal is an acquisition of the GM-2505 program only, not the entire company; Gilgamesh spins off a new entity (Gilgamesh Pharma Inc.) retaining its other programs, including blixeprodil (GM-1020), and the existing AbbVie collaboration. Date is the announcement date; close was subject to customary closing conditions with no specific close date disclosed.
- May 13, 2024PartnershipAbbVie–Gilgamesh collaboration and option-to-license agreementAbbVie and Gilgamesh entered a collaboration and option-to-license agreement to develop next-generation therapies (neuroplastogens) for psychiatric disorders, encompassing Gilgamesh's two lead clinical programs GM-1020 and GM-2505, both then in Phase 2 for major depressive disorder. Gilgamesh received $65 million upfront and was eligible for up to $1.95 billion in aggregate option fees and milestones plus tiered royalties. Upon exercise of an option, AbbVie would lead development and commercialization.
Recent activity
- Jan 6, 2026Phase changeBlixeprodil (GM-1020)·Major depressive disorderPhase 2Positive Phase 2a topline; -6.3 MADRS vs placebo at 24h (p=0.006); 53% Day-42 remission. Late-stage studies planned for 2026.source ↗
- Aug 25, 2025Phase changeBretisilocin (GM-2505)·Major depressive disorderPhase 2AbbVie announced agreement to acquire bretisilocin (GM-2505), up to $1.2B.source ↗
- May 27, 2025Phase changeBretisilocin (GM-2505)·Major depressive disorderPhase 2Positive Phase 2a topline in MDD: 94% MADRS remission at Day 29.source ↗
- May 1, 2024Phase changeBlixeprodil (GM-1020)·Major depressive disorderPhase 2Phase 2a MDD trial initiated; first subject dosed.source ↗
- Nov 30, 2023Phase changeBretisilocin (GM-2505)·Major depressive disorderPhase 1Phase 1 SAD completed; single IV doses produced 60-90 min psychedelic effects, well tolerated.source ↗
Trials recruiting · 1 recruiting of 2 sponsored
- Phase 2Bretisilocin (GM-2505)
Phase 2a Study of Two Repeated Doses of GM-2505 in Major Depressive Disorder
Competitive landscape
Other companies developing against Gilgamesh Pharmaceuticals, Inc.'s targets or indications.
- Axsome Therapeutics, Inc.2 compoundsNMDA receptorMajor depressive disorder
- Beckley Psytech Limited1 compound5-HT2AMajor depressive disorder
- COMPASS Pathways plc1 compound5-HT2AMajor depressive disorder
- Definium Therapeutics, Inc.1 compound5-HT2AMajor depressive disorder
- Delix Therapeutics, Inc.1 compound5-HT2AMajor depressive disorder
- Helus Pharma2 compounds5-HT2AMajor depressive disorder
- Intra-Cellular Therapies, Inc.2 compounds5-HT2AMajor depressive disorder
- Mindset Pharma Inc.1 compound5-HT2AMajor depressive disorder
- Vanda Pharmaceuticals Inc.2 compounds5-HT2AMajor depressive disorder
- ACADIA Pharmaceuticals Inc.1 compound5-HT2A
- Alto Neuroscience, Inc.2 compoundsMajor depressive disorder
- Atai Beckley N.V. (AtaiBeckley)1 compound5-HT2A
