Pasithea Therapeutics Announces Positive PAS-004 Tablet Pharmacokinetic (PK) Data in Ongoing Phase 1/1b Trial in Adult NF1 Patients

On November 21, 2025 Pasithea Therapeutics Corp. (Nasdaq: KTTA) ("Pasithea" or the "Company"), a clinical-stage biotechnology company developing PAS-004, a next-generation macrocyclic oral MEK inhibitor for the treatment of neurofibromatosis type 1-associated plexiform neurofibromas (NF1-PN), reported positive tablet PK data from ongoing Phase 1/1b open-label study evaluating PAS-004 in adult patients with neurofibromatosis type 1 (NF1) with symptomatic and inoperable, incompletely resected, or recurrent plexiform neurofibromas (NCT06961565).

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Pharmacokinetics (PK)

PAS-004 has demonstrated in the tablet formulation (4mg and 8mg cohorts):

Linear PK and dose-proportionality
PK curve with Cmax/Cmin ratio <2, with Cmax and Cmin above the IC50 (half-maximal inhibitory concentration) from our cellular assay

Long half-life (~57 hours)

Cohort 1 (4mg tablet) has demonstrated:

AUC: 1,120 ng·h/mL

Cmax: 58.1 ng/mL

Cmin: 37.6 ng/mL
Cohort 2 (8mg tablet) has demonstrated:

AUC: 2,290 ng·h/mL

Cmax: 118 ng/mL

Cmin: 75.4 ng/mL
Dose normalized exposures following once daily administration of PAS-004 tablets were approximately 3-fold higher than those following administration with the capsule formulation, resulting in the 8mg tablet area under the curve (AUC) and Cmax being slightly greater than those of the 22mg capsule. The tablet formulation has demonstrated less patient variability and a similar Tmax range when compared to the capsule formulation. This is consistent with the pre-clinical evaluation of the two formulations in the dog toxicology studies.

Graph 1 below represents the tablet PK curve at steady state for the 4mg and 8mg doses and Graph 2 below represents the 8mg tablet PK curve at steady state as compared to 22mg capsule dose at steady state from our ongoing Phase 1 trial in advanced cancer patients.

(Press release, Pasithea Therapeutics, NOV 21, 2025, View Source [SID1234660866])