Rare Daily Staff

The European Medicines Agency granted Krystal Biotech PRIME (Priority Medicines) designation for KB103, a first-in-class topical gene therapy for the treatment of the rare disease dystrophic epidermolysis bullosa.

Dystrophic epidermolysis bullosa (DEB) is one of the most severe forms of epidermolysis bullosa, a group of rare genetic skin diseases. DEB is caused by a mutation in the COL7A1 gene which is responsible for the formation of the collagen type C7 protein that anchors fibrils that bind the inner and outer skin layers together. The mutation causes a loss of the anchoring fibrils resulting in fragile skin.

People with DEB live with constant pain and have a high risk of malnutrition and infections. Symptoms include poorly healing wounds, skin infections, fusion of fingers and toes, anemia, gastrointestinal tract problems and with adulthood some develop very aggressive forms of skin cancer. There are no approved treatment options available that target the underlying cause of DEB.


KB103, Krystal’s lead product candidate, is a gene therapy to treat DEB. KB103 is a replication-defective, non-integrating viral vector HSV-1 that has been engineered to deliver functional human COL7A1 genes directly to a patient’s dividing and non-dividing skin cells. HSV-1 can penetrate skin cells more efficiently than other viral vectors. Its high payload capacity allows it to accommodate large or multiple genes and its low immunogenicity makes it a suitable choice for direct and repeat delivery to the skin.

The EMA awards the PRIME designation to promising medicines that target an unmet medical need. These medicines are considered priority medicines by the EMA. To be eligible and accepted for PRIME, a medicine has to show its potential to benefit patients with unmet medical needs based on early clinical data coupled with non-clinical data. Through PRIME, the EMA offers enhanced support to medicine developers including early interaction and dialogue, and a pathway for accelerated evaluation by the agency. The program is intended to optimize development plans and expedite the review and approval process so that these medicines may reach patients as early as possible.

Krystal’s application was supported by clinical data to date from an ongoing phase 1/2 study coupled with non-clinical data.

“Not only does this validate the importance of a truly transformative treatment for DEB but also allows us to work closely with the EMA to optimize our development plan and help us bring KB103 to patients as quickly as possible,” said Suma Krishnan, founder and chief operating officer of Krystal Biotech.

Photo: Suma Krishnan, founder and chief operating officer of Krystal Biotech

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