Pasithea Therapeutics Corp. (KTTA)

We are a clinical-stage biotechnology company focused on discovering, researching and developing treatments for RASopathies, MAPK pathway-driven tumors and other diseases, including central nervous system disorders. Our lead product candidate, PAS-004, is a next-generation macrocyclic small-molecule allosteric inhibitor of MEK 1/2. We believe it may address the toxicities, adverse event rates and twice-daily dosing associated with FDA-approved MEK inhibitors. The company says PAS-004 has a long half-life of about 60 hours, a low peak-to-trough concentration ratio and stable steady-state drug levels, though its safety and efficacy still require clinical testing.

The pipeline has two product candidates. PAS-004 is being studied in two trials. The first is a Phase 1 first-in-human trial in advanced solid tumors with RAS, NF1 or RAF mutations, or after BRAF/MEK inhibitor failure, run at four U.S. and three Eastern European sites and expected to finish in 2028. Dose escalation has reached cohort 8 (45 mg capsule) in 34 patients, with only grade 1 and 2 treatment-related adverse events, no dose-limiting toxicities and no maximum tolerated dose reached. The second is a Phase 1/1b dose-escalation trial in adults with symptomatic, inoperable NF1-associated plexiform neurofibromas, started in May 2025 at five sites in the U.S., Australia and South Korea. Part A is expected to finish by the end of 2026, with Part B in 2027. PAS-004 has FDA orphan-drug designation for NF1. The first planned indication is NF1 plexiform neurofibromas in adults and children. Other potential uses include cutaneous neurofibromas, ALS, ETS2-driven diseases such as IBD, Noonan syndrome, LMNA cardiomyopathy and BRAF-driven cancers. The second candidate, PAS-001, is an early-stage discovery program for a brain-penetrant small molecule targeting complement component 4A for schizophrenia. The company stopped developing its PAS-003 program for ALS during 2025.

The initial target market is NF1, which affects about one in 3,000 newborns, with roughly 114,000 patients in the U.S. About 30% to 50% of them develop plexiform neurofibromas, and over 95% develop cutaneous neurofibromas, for which no FDA-approved therapy exists. Current FDA-approved treatments for NF1 plexiform neurofibromas are the MEK inhibitors Koselugo (selumetinib) and Gomekli (mirdametinib), and other MEK inhibitors are in trials for this indication. Off-label drugs such as bevacizumab are also used. The company also targets broader RASopathies, MAPK-driven cancers and CNS indications. In November 2025, the ALS Association announced a $1 million award that may support an investigator-initiated PAS-004 trial in ALS.

Near-term plans include completing the ongoing trials and the regulatory-required studies before registrational trials: non-clinical and clinical ADME, developmental and reproductive toxicology, drug-drug interaction and food-effect studies. The company also plans to expand formulation work. PAS-004 is given as a capsule in the advanced cancer study and as a tablet in the NF1 trial, and the tablet is expected to be the commercial formulation. Liquid and topical formulations are under evaluation. The text does not describe suppliers, manufacturing arrangements or headquarters.