Pasithea Therapeutics Corp. announced the activation of four clinical trial sites in the United States. These U.S. clinical trial sites in Texas and Virginia are now open and actively enrolling patients.

This announcement follows the approval from the U.S. Food and Drug Administration (FDA) of the Investigational New Drug (IND) application for PAS-004, and FDA review of the protocol for the Company?s Phase 1 multicenter, open-label trial of PAS-004 in patients with MAPK pathway-driven advanced solid tumors with a documented RAS, NF1 or RAF mutation or patients who have failed BRAF/MEK inhibition. The objective of the Phase 1 study is to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of PAS-004 as well as to evaluate the preliminary anticancer activity (efficacy) of PAS-004 and to define the preliminary recommended Phase 2 dose. The Company's clinical development plan for PAS-004 following the Phase 1 study is to begin a Phase 2 clinical trial in NF1 pediatric and adult patients as soon as safety and PK are established.

Pasithea has selected Novotech as the clinical research organization (CRO) for the Phase 1 trial and will be collaborating in the U.S. with NEXT Oncology, led by Dr. Anthony Tolcher M.D., along with Dr. Ildefonso Rodriguez M.D., acting as principal investigator for the San Antonio, TX site. There are also three other clinical trial sites in Eastern Europe that are expected to open in the coming months. PAS-004 is the first macrocyclic MEK inhibitor to enter human clinical trials, with an expected extended half-life in humans which may provide better compliance rates as well as improved efficacy in NF1.

Macrocycles are known to exhibit stronger binding, better solubility and longer half-life with more selectivity and less off target effect as compared to acyclic small molecules. PAS-004 is a small molecule allosteric inhibitor of MEK 1/2, which are dual-specificity protein kinases, in the MAPK signaling pathway. The MAPK pathway has been implicated in a variety of diseases, as it functions to drive cell proliferation, differentiation, survival and a variety of other cellular functions that, when abnormally activated, are critical for the formation and progression of tumors, fibrosis and other diseases.

MEK inhibitors block phosphorylation (activation) of extracellular signal-regulated kinases (ERK), which can lead to cell death and inhibition of tumor growth. Existing FDA approved MEK inhibitors are marketed for a range of diseases, including certain cancers and neurofibromatosis type 1 (NF1). They believe these MEK inhibitors suffer from certain limitations, including known toxicities.

Unlike current FDA approved MEK inhibitors, PAS-004 is macrocyclic, which believe may lead to improved pharmacokinetic and safety (tolerability) profiles. Cyclization offers rigidity for stronger binding with drug target receptors. PAS-004 was designed to provide a longer half-life with what believe is a better therapeutic window.

Further, believe the potency and safety profile that PAS-004 has demonstrated in preclinical studies may also lead to stronger and more durable response rates and efficacy, as well as better dosing schedules. PAS-004 has been tested in a range of mouse models of various diseases and has completed preclinical testing and animal toxicology studies. Additionally, PAS-004 has received orphan-drug designation from the FDA for the treatment of NF1, which may provide seven years of marketing exclusivity upon approval of an NDA.