On June 16, 2026 Pasithea Therapeutics Corp. (NASDAQ: KTTA) ("Pasithea" or the "Company"), a clinical-stage biotechnology company developing PAS-004, a next-generation macrocyclic MEK inhibitor, reported it has amended the clinical study protocol for the Phase 1/1b trial of PAS-004 in neurofibromatosis type 1 (NF1) patients with symptomatic inoperable, incompletely resected, or recurrent plexiform neurofibroma (PN). The amendments include an update to the dose escalation part of the study (Part A) to allow for the enrollment of additional participants at two additional higher dose levels (24mg and 32mg), the ability to backfill completed dose cohorts (4mg, 8mg, 12mg and 18mg) with up to two participants, and the evaluation of intermediate dose levels.
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In addition, the protocol amendments allow patients to remain on treatment for up to 18 months in Part A, and include additional MRI scans to comprehensively evaluate PN, as well as adding more detailed cutaneous neurofibroma (CN) measurements, including tumor height and volume.
Pasithea has completed enrollment and multi-cycle dosing of the initial 4mg, 8mg, 12mg and 18mg cohorts, and enrolled the 24mg cohort and an intermediate 15mg cohort.
"We believe increasing the breadth and depth of Part A of the NF1 study will help inform dose selection for Part B and our future registrational studies," said Dr. Kartik Krishnan, Chief Medical Officer, Pasithea. "I am pleased that we rapidly enrolled and dosed an additional 6 patients and that the amendments will allow us to provide more comprehensive data in 2026."
This multicenter, phase 1/1b, open-label study is divided into two parts: a dose-escalation phase (part A) and an expansion cohort phase (part B). To date, the dose-escalation phase has enrolled and dosed 18 patients with NF1.
About NF1- PN
Plexiform neurofibromas (PN) are tumors originating from the nerve sheath that grow through and around nerves and may involve multiple nerve branches. Thirty to fifty percent (30-50%) of patients with NF1 will harbor PNs, which can undergo malignant transformation. PN-related morbidities are primarily caused by the direct impact of the tumor on surrounding structures and can be life-threatening when they compress vital organs or when they become malignant.
(Press release, Pasithea Therapeutics, JUN 16, 2026, View Source [SID1234668758])