The U.S. Food and Drug Administration (FDA) approved Vertex’s new drug Orkambi for treatment of cystic fibrosis (CF) on July 2, 2015. This is the first medication specifically intended for CF patients with two copies of a gene mutation known as F508del.
CF is a serious genetic condition characterized by the formation of thick mucus in the lungs, digestive tract and other body regions. It causes severe respiratory problems, digestive problems, infections and diabetes. When mutated, the protein encoded by the F508del gene is not functional, and changes in the gene caused by the mutation disrupt water and chloride transport in the body. Double copies of the mutation, one from each parent, is the main cause of CF.
Vertex’s Orkambi was given the FDA’s breakthrough therapy designation based on preliminary clinical evidence that the drug is better than currently available treatments. Orkambi was additionally reviewed under under the priority review program. This means that it was reviewed for shorter period of time, six months or less, instead of 10 months.
“The FDA encourages manufacturers to develop new and innovative treatments for serious rare diseases like cystic fibrosis,” stated John Jenkins, M.D., director of the Office of New Drugs, Center for Drug Evaluation and Research. “Today’s approval significantly broadens the availability of targeted treatments for the specific defects that cause cystic fibrosis.”
The FDA has also given Orkambi orphan drug designation, which allows for financial incentives, such as clinical trial tax credits, user fee waivers, and eligibility for market exclusivity for the company.
Researchers studied Orkambi’s efficacy and safety in two clinical trials including 1,108 subjects with CF 12 years and older with the F508del mutation. People who took two Orkambi pills every 12 hours experienced improved lung function versus those who took placebo (sugar pill). Orkambi’s side effects were shortness of breath, upper respiratory tract infection, nausea, diarrhea, and rash, as well as increased menstrual bleeding in women.
It is not yet known whether or not Orkambi is effective in people who do not have the F508del mutation.
The approval of Orkambi for CF provides a much needed therapy for this difficult-to-treat disease, specifically in those individuals with the most common cause of CF, the F508del mutation. More CF patients have two copies of the F508del mutation than after other genetic mutation associated with the disease, meaning Orkambi will open up new treatment options for a substantial portion of the cystic fibrosis patient population.