The acquisition comes after the private psychedelic drug developer presented impressive results from a Phase 2 study (N=40) of the candidate at ASCP in May. (We broke the news on that data in early May, before having an in-depth discussion with management later in the month.)

The company reported a rapid and sustained antidepressant effect, with a -18.5 point MADRS change from baseline at 24 hours in the 10 mg group, which grew to a -21.6 point change at Day 14. That’s 9.6 points greater than the reduction seen in the 1 mg group, demonstrating convincing separation.

What’s more, the trial printed a -28.0 point change at Day 29 in the 10 mg + 15 mg arm, with a change of -25.1 at Day 74 suggesting the effect is durable, at least in that small study. In terms of MADRS remission rates (defined as a total score of ≤10), that translates to 70% at Day 14 and 94% at Day 29.

Following those results, some had wondered whether AbbVie—which had originally been very clear that it was only interested in so-called non-hallucinogenic neuroplastogens—might have had its interest piqued.

A rumoured billion-dollar acquisition of Gilgamesh by AbbVie, which became public earlier this month, only further stoked such speculation. In that coverage, we wondered aloud: “Has AbbVie warmed up to psychedelics, or are Gilgamesh’s neuroplastogens driving much of the valuation?” “We think the former”, we concluded.

AbbVie’s story arc, from a narrow interest in non-hallucinogenic psychedelics to today’s acquisition of a decidedly psychedelic candidate, surely makes it clear, then, that big pharma is beginning to change its mind on the class.

Indeed, the substituted tryptamine derivative that AbbVie is set to scoop up is as psychedelic as it gets: even the 1 mg dose used in the Phase 2 study was “very psychoactive”, according to Gilgamesh’s Chief Strategy and Development Officer Jorge Quiroz, who spoke with Psychedelic Alpha in May, and is known to have robust subjective effects.

That makes the news a big catalyst for the psychedelic drug development field more broadly, demonstrating that pharma is willing to dabble in true psychedelics, as opposed to limiting its interest to non-hallucinogenic candidates, or continuing to stand on the sidelines.

But AbbVie is seeking to differentiate its new psychedelic asset from others. In its announcement, AbbVie noted bretisilocin’s “shorter duration of psychoactive experience”, which it suggests sets it apart from longer-acting psychedelics. Speaking to Psychedelic Alpha earlier in the year, Gilgamesh’s Quiroz said that he expects the drug could be used in a two-hour timeframe, similar to Spravato.

“We look forward to advancing bretisilocin to late-stage clinical development”, AbbVie’s Chief Scientific Officer Roopal Thakkar said in a statement.

The acquisition also provides a hint at valuations for these types of candidates.

As aforementioned, rumours had suggested that AbbVie might take the whole company for around $1bn, but today’s details show that the price tag reflects just the lead program. Up to $1.2bn for a phase 2 asset is certainly nothing to be sniffed at, and provides a much-needed comp for other programs in the field.

The deal also allows Gilgamesh “to continue pursuing our broader mission of developing novel, transformative therapies for complex mental health and neurological conditions,” CEO Jonathan Sporn said in a statement.