Miami, November 24, 2025 — Leads & Copy — Pasithea Therapeutics Corp. (Nasdaq: KTTA) announced positive safety, pharmacokinetic (PK), and pharmacodynamic (PD) data from Cohort 7 (37mg capsules) in its ongoing first-in-human trial evaluating PAS-004 in patients with MAPK pathway-driven advanced solid tumors with a documented RAS, NF1, or RAF mutation, or in patients who have failed prior BRAF/MEK inhibition (NCT06299839).
The clinical-stage biotechnology company is developing PAS-004, a next-generation macrocyclic oral MEK inhibitor for the treatment of neurofibromatosis type 1-associated plexiform neurofibromas (NF1-PN).
According to Dr. Tiago Reis Marques, Chief Executive Officer of Pasithea, the initial safety data generated in Cohort 7 (37mg capsules) is highly encouraging. Zero treatment-related adverse events have been observed during the dose-limiting toxicity (DLT) period.
PD data demonstrates the pharmacological profile the company believes is necessary to achieve consistent pathway inhibition over the 24-hour dosing period, while avoiding both periods of excessive suppression and periods of insufficient target engagement.
Dr. Marques stated that the balanced profile will be critical for achieving clinical efficacy while minimizing the most commonly observed adverse events associated with MEK inhibitors. Pasithea believes PAS-004 is particularly well suited for treating diseases involving the MAPK pathway that require chronic dosing over long periods, where sustained long-term pathway suppression at safe and well-tolerated doses is required.
In Cohort 7 (37mg capsules), PAS-004 has demonstrated:
Safety and Tolerability: PAS-004 was safe and well-tolerated, with no dose-limiting toxicities (DLTs) and no treatment-related adverse events observed during the DLT period.
After reviewing the Cohort 7 data, the Safety Review Committee recommended proceeding to Cohort 8 (45mg capsules) without modification.
Pharmacodynamics (PD): At steady-state, individual patient plasma data showed PAS-004 inhibiting phosphorylated extracellular signal-regulated kinase (pERK) at a level of 80% near Cmax.
At steady-state, individual patient plasma data showed PAS-004 inhibiting pERK at a level above 60% at Cmin (24-hour postdose).
Pharmacokinetics (PK): Linear PK and dose-proportionality was observed.
The PK curve exhibited a Cmax/Cmin ratio of less than 2.
AUC: 6,690 ng*h/mL; Cmax: 313 ng/mL; Cmin: 260 ng/mL.
For more information about Pasithea Therapeutics Corp., visit their website. The company is focused on researching and developing PAS-004, its lead drug candidate, a next-generation macrocyclic MEK inhibitor intended for treating RASopathies, MAPK pathway-driven tumors, and other diseases. Pasithea is currently testing PAS-004 in a Phase 1 clinical trial in advanced cancer patients (NCT06299839) and a Phase 1/1b clinical trial in adult patients with neurofibromatosis type 1 (NF1)-associated plexiform neurofibromas (NCT06961565).
Patrick Gaynes
Corporate Communications
pgaynes@pasithea.com
Graph 1: Complete PAS-004 dose escalation curve at steady state in ongoing Phase 1 trial in advanced cancer patients.
Source: Pasithea Therapeutics Corp.
