About Cystic Fibrosis

About Cystic Fibrosis

Cystic fibrosis (CF), the most common inherited genetic disorder in the United States, is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). Lack of functional CFTR in secretory airway epithelia results in defective Cl-, bicarbonate, and thiocyanate secretion, coupled with enhanced Na+ absorption and mucus production, leading to dehydration and acidification of the airway surface liquid. CF is characterized by recurrent chest infections, increased airway secretions, and eventually, respiratory failure. While CF comprises a multiorgan pathology affecting the upper and lower airways, gastrointestinal and reproductive tracts, and the endocrine system, the primary cause of morbidity and mortality in CF is due to progressive lung destruction. According to the US Cystic Fibrosis Foundation (“CFF”), the median age at death for patients with CF in the United States was 30.8 years in 2018.

It is estimated that approximately 30,000 patients in the United States and more than 70,000 patients worldwide are living with CF.  Currently approved CFTR modulating therapies have improved the treatment of CF in a subset of patients with specific genetic mutations that are responsive to therapy. Unfortunately, up to 10% of CF patients harbor genetic mutations that are not expected to be responsive to current therapies, including mutations that result in severely reduced or absent CFTR expression (class I mutations) leading to some of the harshest and deadliest forms of CF. As such, there are no therapies approved for treating this most sensitive patient population. To this end, Krystal has developed KB407, a replication-defective herpes simplex virus type 1 (HSV-1) gene therapy vector encoding human CFTR, for molecular correction of CF.  KB407 is expected to enter clinical trials in 2021.

For more information on Cystic Fibrosis, visit:
Cystic Fibrosis Foundation: https://www.cff.org/