AbbVie has agreed to acquire Gilgamesh Pharmaceuticals’ lead psychedelic candidate bretisilocin for up to $1.2 billion. Bretisilocin, a 5-HT2A receptor agonist with promising phase IIa results in moderate-to-severe major depressive disorder, demonstrated significant symptom reduction and a shorter psychoactive duration compared to earlier psychedelics. This acquisition marks AbbVie’s ongoing commitment to psychiatric treatment innovation, aiming to address unmet needs in depression with novel mechanisms.