Oral Drug Could Treat NF1 Skin Tumors

Adults with neurofibromatosis type 1 may eventually gain a pill option, now that the FDA has cleared early human testing.

Updated on Nov. 3, 2026 in Cancer

Bold flat-color editorial illustration of a single unmarked oral tablet over a faint teal cellular pattern, evoking an experimental pill for neurofibromatosis-related skin tumors. — The FDA has cleared Pasithea Therapeutics to test its oral MEK inhibitor PAS-004 in a placebo-controlled Phase 2 trial for skin tumors in people with neurofibromatosis type 1. AI Illustration. Upload story photo >

Pasithea Therapeutics announced that the FDA has cleared its Investigational New Drug application for PAS-004, an oral MEK inhibitor, to be tested in a placebo-controlled Phase 2 trial for NF1-associated cutaneous neurofibromas. The clearance allows the company to proceed with clinical development of the drug in patients in the United States.

Why it matters

Cutaneous neurofibromas are benign skin tumors that affect the large majority of people with neurofibromatosis type 1, and there are currently no FDA-approved systemic drugs for them. Treatment today depends largely on surgical removal, electrodesiccation, or laser therapy, so a drug taken by mouth that could address these tumors throughout the body would represent a new option for patients.

The FDA cleared the application based on nonclinical and clinical safety, tolerability and pharmacokinetic data, along with early treatment signals from Pasithea's ongoing Phase 1/1b study in adults with NF1-associated plexiform neurofibromas. The upcoming trial is a randomized, placebo-controlled Phase 2 study, and its results are not yet available.

The players

Pasithea Therapeutics Corp.

A clinical-stage biotechnology company listed on Nasdaq under KTTA that develops oral targeted therapies, including the MEK inhibitor PAS-004.

U.S. Food and Drug Administration

The federal agency responsible for reviewing and clearing investigational drugs for human trials and approving treatments for public use in the United States.

The details

PAS-004 is a next-generation oral macrocyclic MEK inhibitor, a drug class that blocks a signaling pathway driving abnormal cell growth. It is designed as a once-daily pill whose long half-life and flat pharmacokinetic profile may support ongoing dosing. The FDA clearance means the company can now run its Phase 2 study under an active IND overseen by the agency's Division of Dermatology and Dentistry.

November 3, 2026: Pasithea announced FDA clearance of its IND application for PAS-004 in cutaneous neurofibromas.

Health Landscape

Current care for NF1-associated cutaneous neurofibromas relies on procedures such as surgical excision, electrodesiccation, and laser therapy, with no approved systemic drug. A pill that could work throughout the body would be a shift from these localized approaches toward treatment that addresses many tumors at once.

If you have neurofibromatosis type 1 and skin tumors, this development signals that a systemic option may eventually become available, though it remains years from approval. It is worth discussing with your physician whether your current skin-tumor management is still the best fit as research progresses.

The takeaway

A drug for skin tumors in NF1 has cleared a key regulatory step, but its benefit is still unproven until the Phase 2 trial reports results. Anyone with NF1 can ask their care team about current options for cutaneous neurofibromas and about clinical trial participation.