Krystal Biotech Receives FDA Platform Designation for Gene Therapy Vector

PITTSBURGH, PA – October 16, 2025 – Krystal Biotech has announced that the FDA has granted a Platform Technology Designation for the genetically modified, non-replicating herpes simplex virus type 1 (HSV-1) viral vector used in its gene therapy pipeline. This designation specifically recognizes the vector’s use in KB801, an investigational treatment for neurotrophic keratitis (NK).

The FDA’s designation is intended to streamline development by allowing companies to leverage existing data from previously approved or investigated products that use the same core technology. Krystal Biotech is the second company to receive this designation, following Sarepta Therapeutics, whose designation was later revoked.

KB801: A Redosable Gene Therapy Eye Drop
KB801 is an eye drop formulation designed to deliver a corrected gene to epithelial cells in the front of the eye, enabling them to consistently produce nerve growth factor (NGF).

→ Current Trial: KB801 is currently being evaluated in the randomized, placebo-controlled Phase 1/2 EMERALD-1 clinical trial.

→ Clinical Benefit: This approach aims to overcome the significant patient burden associated with current NGF eye drop treatments, which require intensive administration up to six times per day.

Leveraging the HSV-1 Platform Success
The HSV-1 vector platform is the basis for Krystal’s FDA-approved product, Vyjuvek (beremagene geperpavec-svdt), a topical and redosable gene therapy gel approved in May 2023 for dystrophic epidermolysis bullosa (DEB).

→ Efficiency: “Receiving a platform technology designation from the FDA is a tremendous milestone… for the potential product development benefits it may provide,” said Suma Krishnan, MSc, MBA, President of Research and Development at Krystal Biotech.

→ Pipeline Acceleration: Krystal is excited to work with the FDA to identify “opportunities to leverage [the] prior experience with FDA-approved Vyjuvek… to accelerate the development of [the] genetic medicines pipeline, starting with KB801,” according to Ms. Krishnan.

The HSV-1 vector is also being explored in an eye drop formulation of Vyjuvek for ocular complications in DEB patients, a condition currently lacking corrective treatment options.

The FDA’s New Designation
The Platform Technology Designation is a relatively new FDA mechanism. Sarepta Therapeutics was the first recipient for its rAAVrh74 vector used in gene therapies for muscular dystrophies. However, the FDA revoked Sarepta’s designation shortly after its grant, following the death of a patient in a clinical trial that used the same AAVrh74 serotype. Krystal Biotech’s designation is being monitored closely as the FDA continues to refine the use and safety parameters of this designation.