Pasithea Therapeutics Announces Positive Initial Safety, Tolerability, Pharmacokinetic (PK), and Preliminary Efficacy Data from its Phase 1 Clinical Trial of PAS-004 in Advanced Cancer

Core Insights - Pasithea Therapeutics Corp. announced promising safety, tolerability, pharmacokinetic (PK), and preliminary efficacy data for PAS-004, a next-generation MEK inhibitor, in its Phase 1 clinical trial [1][3][4] Pharmacokinetics and Dosing - The Phase 1 clinical trial is designed as a multi-center, open-label, dose escalation study to evaluate PAS-004 in patients with advanced solid tumors driven by MAPK pathway mutations [2] - PAS-004 demonstrated a long half-life of approximately 70 hours, allowing for once-daily or less frequent oral dosing, which is a significant improvement over first-generation MEK inhibitors [5][9] - At steady-state, drug levels peaked at about 5 hours with a geometric mean maximum concentration (Cmax) of 16.2 ng/mL for the 2 mg dose and 61.3 ng/mL for the 4 mg dose [5] Safety and Tolerability - No treatment-related adverse events (TRAEs) or dose-limiting toxicities (DLTs) were observed in the first two dosing cohorts, indicating a favorable safety profile [7] - The absence of common side effects associated with MEK inhibitors, such as rash or gastrointestinal toxicity, was noted [7][9] Preliminary Efficacy - A patient with stage 3 colon cancer, who had received four prior lines of therapy, achieved prolonged stable disease while on PAS-004, suggesting early signs of efficacy [1][4] - The patient had a BRAF K601E mutation, which currently lacks approved therapies, highlighting the potential of PAS-004 in treating difficult-to-manage cases [4] Future Directions - The company has initiated dosing for a third cohort at an increased dose of 8 mg and plans to provide periodic updates on the trial's progress [8][9] - PAS-004 is positioned to potentially outperform current MEK inhibitors in terms of safety, reduced administration frequency, and efficacy across various indications, including neurofibromatosis type 1 (NF1) and other MAPK-driven cancers [4][9]