Pasithea Therapeutics Corp. announced the first cohort of 3 patients have commenced dosing. PAS-004 is being evaluated in a Phase 1 multicenter open label clinical trial (NCT06299839) in patients with MAPK pathway driven advanced solid tumors with a documented RAS, NF1 or RAF mutation or patients who have failed BRAF/MEK inhibition.

PAS-004 is the first macrocyclic MEK inhibitor to enter human clinical trials, with an expected extended half-life which may provide better compliance rates, as well as improved efficacy in NF1. Macrocycles are known to exhibit stronger binding, better solubility and longer half-life with more selectivity and less off target effect as compared to acyclic small molecules.