FDA Grants Rare Pediatric Disease Designation to KB105 for TGM-1 Deficient ARCI

This morning, August 23, 2018, the US Food and Drug Administration (FDA) granted a rare pediatric disease designation to Krystal Biotech’s KB105 for the treatment of patients with TGM-1-deficient autosomal recessive congenital ichthyosis (ARCI).

Currently, there are no treatments available for the disease, which affects 20,000 patients worldwide, on average.

"Receiving Rare Pediatric Disease Designation from the FDA is another important step for the KB105 program that includes the recent receipt of Orphan Drug Designation and our anticipated upcoming filing of an IND application," said Krish Krishnan, CEO of Krystal Biotech, to Rare Disease Reoprt^®. "Our primary focus is on bringing transformative treatments to patients and families affected by debilitating rare skin diseases and milestones such as these help to facilitate this process."

A gene therapy, KB105 is a replication-defective, non-integrating viral vector (HSV-1) engineered to employ Krystal's STAR-D platform to deliver functional human TGM-1 gene directly to the dividing and non-dividing skin cells in patients, according to Krystal Biotech. HSV-1 is Krystal's replication-deficient, non-integrating viral vector that can penetrate skin cells more efficiently than other viral vectors.

The loss of TGM-1-activity—a vital epidermal enzyme that facilitates the formation of the epidermal barrier, prevents dehydration, and protects the skin from unwanted toxins and surface microorganisms—results in ARCI, a severe genetic skin disease. The majority of patients with a TGM-1-deficiency exhibit lifelong pronounced scaling with increased transepidermal water loss. The rare disease is associated with increased mortality in the neonatal period and a dramatic impact on quality of life.

While there is preclinical data on KB105 used in animal models, these data have yet to be presented at a conference, a representative from Krystal Biotech told Rare Disease Report^® in a past interview.

Earlier this month, KB105 also received an orphan drug designation from the FDA.