Pasithea Therapeutics Completes Enrollment and Initial Dosing of First Cohort in Phase 1/1b Trial for PAS-004 in Adult NF1 Patients.

Pasithea Therapeutics has completed enrollment and initial dosing of three subjects in Cohort 1 of its Phase 1/1b clinical trial evaluating PAS-004 in adult NF1 patients with symptomatic and inoperable, incompletely resected, or recurrent plexiform neurofibromas. The trial aims to evaluate the safety and tolerability of PAS-004, a next-generation macrocyclic MEK inhibitor, and identify the recommended Part B dose or Maximum Tolerated Dose. Preliminary efficacy on target PN volume and quality of life will also be assessed.

Pasithea Therapeutics Corp. (NASDAQ: KTTA) has achieved a significant milestone in its clinical development program by completing enrollment and initial dosing of three subjects in Cohort 1 of its Phase 1/1b trial for PAS-004. The trial evaluates a novel once-daily macrocyclic MEK inhibitor in adult patients with neurofibromatosis type 1 (NF1) who have symptomatic and inoperable plexiform neurofibromas. The company expects to present initial interim safety, tolerability, biomarker, and preliminary efficacy data in Q1 2026.

The primary objective of the Phase 1/1b study (NCT06961565) is to evaluate the safety and tolerability of PAS-004 when administered for one 28-day treatment cycle in adult NF1 participants with at least one and up to two additional target plexiform neurofibromas (PNs) that are symptomatic and inoperable, incompletely resected, or recurrent. Secondary objectives include identifying the recommended Part B dose (RPBD) or Maximum Tolerated Dose (MTD) of PAS-004, characterizing the pharmacokinetics (PK) and pharmacodynamics (PD) profile of PAS-004, evaluating the preliminary efficacy of PAS-004 on target PN volume, and assessing the impact of PAS-004 on quality of life (QOL) and physical symptoms attributed to the target PN.

The trial will be conducted in two parts. In Part A, up to 24 eligible participants will be enrolled sequentially to receive one of four planned dose levels of PAS-004 tablets (4mg, 8mg, 12 mg, and 18mg) in a modified 3+3 design. Part B will enroll up to 24 eligible participants in parallel to receive one of two planned dose levels of PAS-004 tablets, dosed at the RPBD level and at a dose level below the RPBD for up to six continuous 28-day treatment cycles.

Pasithea Therapeutics is a clinical-stage biotechnology company primarily focused on the research and development of its lead drug candidate, PAS-004, a next-generation macrocyclic MEK inhibitor intended for the treatment of RASopathies, MAPK pathway-driven tumors, and other diseases. The company 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).

The completion of enrollment and initial dosing marks a key milestone in Pasithea's mission to develop PAS-004 as a potential best-in-class, next-generation MEK inhibitor for the treatment of NF1. PAS-004 is a once-daily dosed MEK inhibitor in development for the treatment of NF1 patients with plexiform neurofibromas, as opposed to the current FDA-approved therapies that require twice-daily dosing. This may potentially offer a best-in-class advantage in terms of patient compliance.

The study is planned to be conducted at five clinical trial sites in Australia, South Korea, and the U.S. [1]

References:
[1] https://www.globenewswire.com/news-release/2025/07/31/3124857/0/en/Pasithea-Therapeutics-Completes-Enrollment-and-Initial-Dosing-of-First-Cohort-from-its-Phase-1-1b-Clinical-Trial-of-PAS-004-in-Adult-NF1-Patients.html