ABBV Buys Rights to Bretisilocin, a Novel Psychedelic for Depression

AbbVie ABBV has announced a deal with private neuroscience biotech, Gilgamesh Pharmaceuticals, to acquire the latter’s lead pipeline candidate, bretisilocin (GM-2505), a novel therapy being developed for treating major depressive disorder
(MDD).

Gilgamesh is currently developing bretisilocin, a novel, psychedelic compound, in a phase II study for treating moderate-to-severe MDD. Data from a phase II study on bretisilocin, announced in May this year, showed that the candidate led to a rapid, robust and durable antidepressant effect in MDD patients. In the study, bretisilocin demonstrated a statistically significant reduction in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score compared to the low-dose psychoactive comparator. MADRS is a scale used to measure the severity of depressive symptoms. Patients improved by an average of 21.6 points on MADRS versus 12.1 points for the comparator at Day 14.

AbbVie’s stock has gained 20.1% so far this year compared with an increase of 1.6% for the industry.

Terms of the ABBV/Gilgamesh Deal

Psychedelic compounds, including 5-HT2A receptor agonists like bretisilocin, produce a much shorter psychedelic experience than existing psychedelics which makes them more patient-friendly. However, despite the shorter sessions, they offer long-lasting therapeutic effects.

For acquiring Gilgamesh's bretisilocin program, AbbVie will make a payment of up to $1.2 billion, which includes an upfront payment and development milestones. Separately, Gilgamesh will spin off its other drug programs, like NMDA antagonist blixeprodil and ibogaine analog, into a new company, Gilgamesh Pharma, while AbbVie takes full control of bretisilocin.

In May last year, AbbVie inked an option and licensing deal with Gilgamesh to research and develop next-generation therapies for psychiatric disorders. The deal remains in place and will be transferred to Gilgamesh Pharma.

ABBV’s Recent Deals in Neuroscience Space

AbbVie has been on an acquisition spree in the past couple of years to bolster the early-stage pipeline that should drive long-term growth. It has signed some early-stage deals in the neuroscience area.

In December last year, it acquired Aliada, a private biotech whose lead pipeline candidate is ALIA-1758, an anti-pyroglutamate amyloid beta (3pE-Aβ) antibody, which is being developed in a phase I study for Alzheimer's disease. Last year, AbbVie also acquired neuroscience drugmaker, Cerevel Therapeutics, which added the latter’s novel pipeline candidates being studied across a range of psychiatric and neurological disorders, including schizophrenia, Parkinson's disease (PD) and mood disorders. However, in November 2024, two registration-enabling phase II studies on emraclidine, a once-daily, oral candidate for treating schizophrenia added from the Cerevel deal, failed to meet their primary endpoints. Emraclidine was a key reason for AbbVie to buy the company, thus bringing into question the viability of the deal.

AbbVie’s neuroscience drugs have become an important contributor to top-line growth. Sales from AbbVie’s neuroscience portfolio increased 20.3% to around $5 billion in the first half of 2025, driven by higher sales of Botox Therapeutic, depression drug Vraylar and migraine drugs Ubrelvy and Qulipta.

ABBV’s Zacks Rank & Stocks to Consider

AbbVie currently carries a Zacks Rank #3 (Hold).

Some better-ranked large drugmakers are J&J JNJ and Bayer BAYRY, both with a Zacks Rank #2 (Buy). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

J&J’s stock has risen 25.4% in the year-to-date period. The Zacks Consensus Estimate for J&J’s 2025 earnings has risen from $10.60 per share to $10.86 over the past 60 days, while that for 2026 has risen from $10.98 to $11.36.

J&J exceeded earnings expectations in each of the trailing four quarters. It delivered a four-quarter earnings surprise of 5.73%, on average.

Bayer’s stock has risen 67.2% in the year-to-date period. The Zacks Consensus Estimate for Bayer’s 2025 earnings has risen from $1.25 per share to $1.30 over the past 60 days, while that for 2026 has risen from $1.31 to $1.34.

Bayer exceeded earnings expectations in two of the trailing four quarters while missing in one and delivering in-line results in the other. It delivered a four-quarter negative earnings surprise of 3.91%, on average.

Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report

This article originally published on Zacks Investment Research (zacks.com).

Zacks Investment Research