AbbVie Acquires Gilgamesh Pharmaceuticals’ Depression Drug for Up to $1.2 Billion

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August 25, 2025

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Background on Gilgamesh Pharmaceuticals and its Depression Drug

Gilgamesh Pharmaceuticals is a privately-held biopharmaceutical company focused on developing novel therapeutics for the treatment of psychiatric disorders. The company’s lead asset is bretisilocin, an experimental drug targeting major depressive disorder (MDD) with moderate to severe symptoms.

The Acquisition Details

AbbVie, a global biopharmaceutical company, has announced its plan to acquire Gilgamesh Pharmaceuticals’ experimental depression drug, bretisilocin, for up to $1.2 billion. This acquisition will expand AbbVie’s psychiatric product portfolio.

The deal includes an initial payment and additional milestones-based payments. The transaction is subject to closing conditions.

Clinical Trial Results

A phase 2a study of bretisilocin in patients with major depressive disorder (MDD) demonstrated a clinically and statistically significant reduction in the severity of depressive symptoms, according to the press release.

AbbVie’s Commitment to Psychiatric Care

Roopal Thakkar, AbbVie’s Chief Scientific Officer, stated: “This acquisition underscores our commitment to expanding and enhancing psychiatric care through investment in novel therapeutic approaches with the potential to reach patients for whom other treatments have proven ineffective.”

Collaboration Between AbbVie and Gilgamesh

This acquisition follows a collaboration between AbbVie and Gilgamesh last year to develop next-generation therapies for psychiatric disorders. As part of the latest agreement, Gilgamesh will spin off an entity named Gilgamesh Pharma, which is expected to retain its employees and other programs.

“AbbVie’s leadership in neuroscience and commitment to advancing innovative treatments make them the ideal partner to drive bretisilocin’s development while allowing Gilgamesh to continue our broader mission of developing novel and transformative therapies for mental health and complex neurological conditions,” said Jonathan Sporn, CEO of Gilgamesh.

Key Questions and Answers

  • What is Gilgamesh Pharmaceuticals? Gilgamesh Pharmaceuticals is a privately-held biopharmaceutical company focused on developing novel therapeutics for psychiatric disorders.
  • What is bretisilocin? Bretisilocin is Gilgamesh Pharmaceuticals’ lead experimental drug targeting major depressive disorder (MDD) with moderate to severe symptoms.
  • Why is AbbVie acquiring bretisilocin? AbbVie aims to expand its psychiatric product portfolio and demonstrate its commitment to enhancing psychiatric care through novel therapeutic approaches.
  • What are the terms of the acquisition? The deal includes an initial payment and additional milestones-based payments, subject to closing conditions.
  • What were the results of the clinical trial for bretisilocin? A phase 2a study showed a clinically and statistically significant reduction in the severity of depressive symptoms in patients with major depressive disorder (MDD).
  • What is the collaboration history between AbbVie and Gilgamesh? AbbVie and Gilgamesh have collaborated since last year to develop next-generation therapies for psychiatric disorders. Gilgamesh will spin off an entity named Gilgamesh Pharma as part of the latest agreement.