The U.S. Food and Drug Administration has approved Trikafta (elexacaftor/ivacaftor/tezacaftor), the first triple combination therapy available to treat patients with the most common cystic fibrosis mutation. Trikafta is approved for patients 12 years and older with cystic fibrosis who have at least one F508del mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which is estimated to represent 90% of the cystic fibrosis population.
“At the FDA, we’re consistently looking for ways to help speed the development of new therapies for complex diseases, while maintaining our high standards of review. Today’s landmark approval is a testament to these efforts, making a novel treatment available to most cystic fibrosis patients, including adolescents, who previously had no options and giving others in the cystic fibrosis community access to an additional effective therapy,” said acting FDA Commissioner Ned Sharpless, M.D.
Cystic fibrosis, a rare, progressive, life-threatening disease, results in the formation of thick mucus that builds up in the lungs, digestive tract and other parts of the body. It leads to severe respiratory and digestive problems as well as other complications such as infections and diabetes. Cystic fibrosis is caused by a defective protein that results from mutations in the CFTR gene. While there are approximately 2,000 known mutations of the CFTR gene, the most common mutation is the F508del mutation.
Trikafta is a combination of three drugs that target the defective CFTR protein. It helps the protein made by the CFTR gene mutation function more effectively. Currently available therapies that target the defective protein are treatment options for some patients with cystic fibrosis, but many patients have mutations that are ineligible for treatment.
The efficacy of Trikafta in patients with cystic fibrosis aged 12 years and older was demonstrated in two trials. The first trial was a 24-week, randomized, double-blind, placebo-controlled trial in 403 patients who had an F508del mutation and a mutation on the second allele that results in either no CFTR protein or a CFTR protein that is not responsive to ivacaftor or tezacaftor/ivacaftor alone. The second trial was a four-week, randomized, double-blind, active-controlled trial in 107 patients who had two identical F508del mutations.
In each trial, the primary analysis looked at increases in the percent predicted forced expiratory volume in one second, known as ppFEV1, which is an established marker of cystic fibrosis lung disease progression. Trikafta increased the ppFEV1 in both trials. In the first trial, it increased mean ppFEV1 13.8% from baseline compared to placebo. In the second trial, it increased mean ppFEV1 10% from baseline compared to tezacaftor/ivacaftor. In the first trial, treatment with Trikafta also resulted in improvements in sweat chloride, number of pulmonary exacerbations (worsening respiratory symptoms and lung function), and body mass index (weight-to-height ratio) compared to placebo.
