In 2020, the U.S. FDA granted Orphan Drug designation to KB407, an investigational gene therapy for patients with cystic fibrosis (CF). More recently, at the start of 2023, the therapy also earned Orphan status in the European Union, shares Cystic Fibrosis News Today. 

Orphan designation, or Orphan Medicinal Products designation, is designed to facilitate the development and expedite the review of therapies for rare, debilitating, or life-threatening conditions. In the EU, “rare” refers to conditions affecting fewer than 5 in every 10,000 people. Upon receiving this designation, the drug developer receives benefits such as protocol assistance, fee reductions, and ten years of market exclusivity following the drug’s approval. Learn more about Orphan status here. 

What is KB407?

Developed by Krystal Biotech, KB407 is an inhaled gene therapy which uses replication incompetent herpes simplex virus 1 (HSV-1). In a presentation from Krystal Biotech, the company explains that KB407 delivers two healthy, normal copies of CFTR to the person. Using a commercially available nebulizer, Krystal Biotech believes that KB407 can be administered in less than 30 minutes.

Preclinical studies have shown that KB407 helps promote normal CFTR protein development in lung cells. The therapy is also being evaluated in different clinical trials; though data is not yet available, these studies will offer more insight into the impact of KB407 on respiratory health and functionality. 

About Cystic Fibrosis (CF) 

Cystic fibrosis is a rare genetic disorder which can cause progressive (worsening) digestive system and respiratory system damage. CFTR gene mutations alter the regulation of salt movement in the body. As a result, people with cystic fibrosis often have thick, sticky mucus which accumulates in their system. This can prevent the release of digestive enzymes, trap bacteria, and cause a number of breathing issues. Cystic fibrosis is most common in Caucasian newborns as opposed to newborns of other ethnicities. Symptoms can, but do not always, include:

• Salty-tasting skin
• Shortness of breath and/or difficulty breathing
• Exercise intolerance
• A persistent cough that produces thick mucus
• Frequent lung infections
• Wheezing
• Stuffy nose
• Infertility (in males)
• Poor weight gain
• Greasy, foul-smelling stool
• Constipation

Treatment options for cystic fibrosis vary and include surgery, exercise therapy, physical therapy, pancreatic enzymes, bronchodilators, anti-inflammatory medications, and more.