Pasithea Therapeutics Announces Grant of Rare Pediatric Disease Designation (RPDD) by FDA to PAS-004 for Treatment of Neurofibromatosis Type 1 (NF1)

Rhea-AI Summary

Pasithea Therapeutics (NASDAQ: KTTA) announced the U.S. FDA granted Rare Pediatric Disease Designation to PAS-004 for treatment of Neurofibromatosis type 1 (NF1) on April 20, 2026. The designation could make Pasithea eligible for a Priority Review Voucher (PRV); disclosed PRV sales have ranged from $150–$205 million in the last 12 months.

PAS-004 already holds Orphan Drug and Fast Track designations and is in a Phase 1/1b multicenter dose-escalation trial (NCT06961565) in adults with symptomatic NF1 plexiform neurofibromas.

Positive

• Rare Pediatric Disease Designation for PAS-004 by FDA
• PRV market value context: disclosed sales $150–$205M in last 12 months
• Multiple regulatory designations: Orphan Drug and Fast Track also granted

Negative

• PAS-004 remains in a Phase 1/1b trial with no NDA/BLA approval yet
• RPDD does not guarantee approval or issuance of a Priority Review Voucher

News Market Reaction – KTTA

-3.38% 2.0x vol

14 alerts

-3.38% Session close to close

+13.6% Peak Tracked

-17.3% Trough Tracked

$18.52M Market Cap

2.0x Rel. Volume

In the Apr 20 session, KTTA declined 3.38%, reflecting a moderate negative market reaction. Argus tracked a peak move of +13.6% during that session. Argus tracked a trough of -17.3% from its starting point during tracking. Our momentum scanner triggered 14 alerts that day, indicating notable trading interest and price volatility. Trading volume was elevated at 2.0x the daily average, suggesting increased selling activity.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement adds FDA Rare Pediatric Disease Designation for PAS-004 in NF1 to Pasithea’s exist...

Analysis

This announcement adds FDA Rare Pediatric Disease Designation for PAS-004 in NF1 to Pasithea’s existing Orphan Drug and Fast Track designations, potentially enabling access to a transferable Priority Review Voucher, which has recently sold for $150–$205 million. Investors may watch upcoming Phase 1/1b data from trial NCT06961565 and future regulatory milestones to assess how this designation supports the broader PAS-004 development strategy.

Key Figures

U.S. NF1 patients: approximately 115,000 individuals Rare disease threshold: fewer than 200,000 people Pediatric age range: birth to 18 years +3 more

6 metrics

U.S. NF1 patients approximately 115,000 individuals Prevalence of Neurofibromatosis type 1 in the U.S.

Rare disease threshold fewer than 200,000 people U.S. prevalence criterion for rare pediatric disease designation

Pediatric age range birth to 18 years Age range primarily affected for RPDD eligibility

PRV sale range $150–$205 million Disclosed Priority Review Voucher sales in last 12 months

Trial phase Phase 1/1b Multicenter open-label dose escalation trial of PAS-004 in adult NF1-PN

Clinical trial ID NCT06961565 Identifier for PAS-004 NF1-PN Phase 1/1b study

Historical Context

5 past events · Latest: Apr 01 (Positive)

Pattern 5 events

Date	Event	Sentiment	24h Move	Catalyst
Apr 01	FDA Fast Track	Positive	+0.3%	FDA granted Fast Track designation to PAS-004 for NF1-associated plexiform neurofibromas.
Feb 17	Conference appearance	Neutral	-2.5%	Company scheduled a virtual presentation and investor meetings at a healthcare conference.
Jan 13	Program outlook, financing	Positive	-3.3%	Updated PAS-004 timelines and highlighted prior $60M offering funding operations through H1 2028.
Dec 02	Offering closing	Neutral	+2.6%	Closed $60M public offering of 80M shares or pre-funded warrants at $0.75.
Nov 28	Offering pricing	Neutral	+38.7%	Priced $60M public offering at $0.75 per share, expanding capital for clinical plans.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Pattern Detected

Recent KTTA news has mostly seen aligned, modest price moves, with one divergence on a clinical/strategic update.

Recent Company History

Over the last few months, Pasithea has focused on advancing PAS-004 and strengthening its balance sheet. The company gained Fast Track designation on Apr 1, 2026 with a small positive move, presented at an Oppenheimer conference, and outlined PAS-004 timelines alongside a previously completed $60M financing. Two November 2025 offerings, including pricing and closing of a $60M deal, helped extend runway. Today’s RPDD adds another FDA designation to this regulatory and clinical momentum.

Key Terms

rare pediatric disease designation, priority review voucher, new drug application, biologics license application, +4 more

8 terms

rare pediatric disease designation regulatory

"announced that the U.S. Food and Drug Administration (FDA) has granted Rare Pediatric Disease Designation to PAS-004"

A rare pediatric disease designation is an official regulatory status given to a drug or therapy that targets a serious or life‑threatening condition primarily affecting children and is uncommon in the population. It matters to investors because the status often brings financial and development perks — such as tax credits, reduced fees, faster review and periods of market protection — which can lower costs, speed approval and improve the commercial outlook; think of it as a VIP pass that makes bringing a scarce, child‑focused treatment to market easier and potentially more profitable.

priority review voucher regulatory

"may be eligible for a Priority Review Voucher (“PRV”) which can be redeemed to obtain priority review"

A priority review voucher is a transferable regulatory incentive that lets a company move a future drug or device application to the front of the review line, shortening the review period by several months. For investors it matters because the voucher can speed up market access for a high-value product or be sold to other companies for significant cash, acting like a tradable fast-pass that can accelerate revenue or create immediate financial upside.

new drug application regulatory

"approval of a new drug application (NDA) or biologics license application (BLA) for a rare pediatric disease"

A new drug application is a formal request submitted to government regulators seeking approval to market a new medicine. It is like a detailed proposal that shows the drug has been tested for safety and effectiveness. For investors, receiving approval signals that the drug may soon become available for sale, potentially leading to revenue growth and impacting the company's value.

biologics license application regulatory

"approval of a new drug application (NDA) or biologics license application (BLA) for a rare pediatric disease"

A biologics license application is a formal request submitted to regulatory authorities seeking approval to market a new biological medicine, such as vaccines or treatments made from living organisms. It is a comprehensive review process that evaluates the safety, effectiveness, and manufacturing quality of the product. For investors, receiving approval signals that a biological therapy can be sold to the public, potentially leading to revenue growth and market success.

macrocyclic mek inhibitor medical

"developing PAS-004, a next-generation macrocyclic MEK inhibitor, today announced that the U.S. Food and Drug Administration"

A macrocyclic MEK inhibitor is a type of cancer drug built around a large ring-shaped molecule that blocks the MEK protein, a key switch in a cell growth pathway often hijacked by tumors. For investors, these drugs matter because they can slow or stop tumor growth where that pathway is active, so clinical results, safety issues, and regulatory decisions can quickly change a biotech’s value—think of it as cutting the fuel line to an engine driving tumor growth.

phase 1/1b medical

"conducting a Phase 1/1b multicenter, open-label, dose escalation trial of PAS-004"

Phase 1/1b describes early-stage clinical testing in humans where researchers first assess a drug’s safety, tolerable dose range and how the body processes it; phase 1b often means small expansion groups to explore the best dose and look for initial signs the treatment might work. For investors, these studies are like the first road tests of a new product—positive results reduce risk and increase value potential, while negative or unclear results raise uncertainty about future development.

open-label medical

"Phase 1/1b multicenter, open-label, dose escalation trial of PAS-004 in adult participants"

Open-label describes a situation where everyone involved in a study or process knows the full details, such as who is receiving a treatment or intervention. For investors, understanding whether a project or product is open-label helps gauge the level of transparency and potential biases, influencing trust and decision-making. It’s like knowing whether a test or experiment is conducted openly or behind closed doors.

dose escalation medical

"Phase 1/1b multicenter, open-label, dose escalation trial of PAS-004 in adult participants"

Dose escalation is the process of gradually increasing the amount of a treatment or substance over time. In finance, it can refer to slowly raising investments or commitments to manage risk and assess performance. For investors, understanding dose escalation helps gauge how companies or strategies adjust their approaches, which can impact future growth or stability.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Rare Pediatric Disease Designation may render Pasithea eligible to receive a Priority Review Voucher (PRV) 

MIAMI, April 20, 2026 (GLOBE NEWSWIRE) -- Pasithea Therapeutics Corp. (NASDAQ: KTTA) (“Pasithea” or the “Company”), a clinical-stage biotechnology company developing PAS-004, a next-generation macrocyclic MEK inhibitor, today announced that the U.S. Food and Drug Administration (FDA) has granted Rare Pediatric Disease Designation to PAS-004 for treatment of Neurofibromatosis type-1 (NF1).

The FDA grants RPDD for serious or life-threatening diseases in which the serious or life-threatening manifestations primarily affect individuals aged from birth to 18 years and affect fewer than 200,000 people in the U.S. There are approximately 115,000 individuals in the U.S living with NF1.

Under the FDA's Rare Pediatric Disease Priority Review Voucher program, a sponsor who receives an approval of a new drug application (NDA) or biologics license application (BLA) for a rare pediatric disease may be eligible for a Priority Review Voucher (“PRV”) which can be redeemed to obtain priority review for a subsequent marketing application for a different product. The PRV may be sold or transferred to another sponsor. In the last 12 months, disclosed PRV sales have ranged from $150–$205 million.

“We are pleased to have received rare pediatric disease designation from the U.S. FDA for our PAS-004 program for patients with NF1,” said Dr. Tiago Reis Marques, chief executive officer of Pasithea. “This designation for PAS-004 reinforces the potential of PAS-004 to address this serious condition.”

PAS-004 has so far been granted the following FDA regulatory designations: Orphan Drug Designation, Fast Track Designation and Rare Pediatric Disease Designation.

The Company is currently conducting a Phase 1/1b multicenter, open-label, dose escalation trial of PAS-004 in adult participants with symptomatic, inoperable, incompletely resected, or recurrent NF1-PN (NCT06961565).

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.

About Pasithea Therapeutics Corp.
Pasithea 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 1clinical trial in patients with advanced cancer (NCT06299839), and a Phase 1/1bclinical trial in patients with neurofibromatosis type 1 (NF1)-associated plexiform neurofibromas with symptomatic and inoperable, incompletely resected, or recurrent PN (NCT06961565).

Forward Looking Statements

This press release contains statements that constitute “forward-looking statements” made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include statements regarding the Company’s ongoing Phase 1 clinical trial of PAS-004 in advanced cancer patients, the Company’s ongoing Phase 1/1b clinical trial of PAS-004 in adult NF1 patients, and the safety, tolerability, pharmacokinetic (PK), pharmacodynamics (PD) and preliminary efficacy of PAS-004, as well as all other statements, other than statements of historical fact, regarding the Company’s current views and assumptions with respect to future events regarding its business, as well as other statements with respect to the Company’s plans, assumptions, expectations, beliefs and objectives, the success of the Company’s current and future business strategies, product development, pre-clinical studies, clinical studies, clinical and regulatory timelines, market opportunity, competitive position, business strategies, potential growth and financing opportunities and other statements that are predictive in nature. Forward-looking statements are subject to numerous conditions, many of which are beyond the control of the Company. While the Company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to the Company on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties, including risks that future clinical trial results may not match results observed to date, may be negative or ambiguous, or may not reach the level of statistical significance required for regulatory approval, as well as other factors set forth in the Company’s most recent Annual Report on Form 10-K, Quarterly Report on Form 10-Q and other filings made with the U.S. Securities and Exchange Commission (SEC). Thus, actual results could be materially different. The Company undertakes no obligation to update these statements, whether as a result of new information, future events, or otherwise, after the date of this release, except as required by law.

Pasithea Therapeutics Contact

Patrick Gaynes
Investor Relations
pgaynes@pasithea.com

FAQ

What does the FDA Rare Pediatric Disease Designation mean for PAS-004 (KTTA)?

It means PAS-004 is recognized for a serious pediatric condition and may be PRV-eligible. According to Pasithea, RPDD acknowledges NF1 primarily affects individuals under 18 and could make the program eligible for a Priority Review Voucher if PAS-004 later gains approval.

How could a Priority Review Voucher affect Pasithea (KTTA) value?

A PRV can have material commercial value if obtained and sold or used. According to Pasithea, disclosed PRV sales ranged from $150–$205 million in the past 12 months, providing potential non-dilutive value to the company or buyers.

What regulatory milestones has PAS-004 already achieved for NF1 (KTTA)?

PAS-004 has Orphan Drug and Fast Track designations in addition to RPDD. According to Pasithea, these designations aim to expedite development and regulatory review for treatments addressing NF1.

What is the current clinical status of PAS-004 for NF1 (KTTA)?

PAS-004 is in a Phase 1/1b multicenter, open-label, dose-escalation trial. According to Pasithea, the study (NCT06961565) enrolls adults with symptomatic, inoperable, incompletely resected, or recurrent NF1 plexiform neurofibromas.

How prevalent is Neurofibromatosis type 1 in the U.S., relevant to KTTA's news?

About 115,000 people in the U.S. live with NF1, meeting the FDA rare pediatric threshold. According to Pasithea, RPDD applies when serious manifestations primarily affect individuals birth to 18 and fewer than 200,000 U.S. cases exist.

Does Rare Pediatric Disease Designation guarantee FDA approval or a PRV for PAS-004 (KTTA)?

No, RPDD alone does not guarantee approval or a PRV will be awarded. According to Pasithea, RPDD may make a sponsor eligible for a PRV only if a subsequent NDA or BLA for the rare pediatric disease is approved.