October 23, 2019
The US FDA has approved Trikafta™ (elexacaftor/tezacaftor/ivacaftor and ivacaftor), manufactured by Vertex Pharmaceuticals, to treat patients who have cystic fibrosis, are at least 12 years of age, and have at least one F508del mutation in the CFTR gene.
Cystic fibrosis affects an estimated 75,000 individuals worldwide and occurs as a result of a missing or mutations in the CFTR gene. These mutations cause a key CFTR protein to be missing or defective. In most cases, patients who have cystic fibrosis have an F508del mutation. The missing or defective protein causes an imbalance in the flow of salt and water into and out of cells in the body. As a result, a thick, sticky mucus accumulates around the organs. In many cases, this raises the risk of lung infection and contributes to progressive lung damage, though cystic fibrosis can damage other organs. The median life expectancy for patients who have the disease is approximately 30 years.
Trikafta addresses the root cause of cystic fibrosis by helping to increase the quantity and function of the F508del-CFTR protein at the cell surface. It is the first treatment to address the root cause that is FDA approved for use by approximately 6,000 patients who have one F508del mutation and one minimal function mutation (F/MF). According to Vertex Pharmaceuticals, up to 90% of the cystic fibrosis patient population may be eligible for treatment with Trikafta.
In clinical trials, researchers evaluated Trikafta’s efficacy using ppFEV1, or percent predicted forced expiratory volume in one second, which is a measurement of lung function commonly used to assess cystic fibrosis disease severity. In one trial, Trikafta delivered a 13.8% ppFEV1 improvement from baseline in mean ppFEV1 compared to placebo. In another, the improvement in ppFEV1 was 10% from baseline compared to treatment with tezacaftor/ivacaftor. Treatment with Trikafta also resulted in improvements in sweat chloride (a marker of cystic fibrosis), number of pulmonary exacerbations (worsening respiratory symptoms and lung function), and body mass index (weight-to-height ratio) compared to placebo.
Trikafta consists of fixed-dosed combination tablets containing elexacaftor 100mg, tezacaftor 50mg, and ivacaftor 75mg, co-packaged with 150mg ivacaftor tablets. Recommended dosing is two combination tablets taken in the morning, and one 150mg ivacaftor tablet taken approximately 12 hours later in the evening. Both morning and evening doses should be taken with fat-containing food. The total dose of Trikafta should be reduced if the patient has moderate hepatic impairment or is taking drugs that are moderate or strong CYP3A inhibitors. Trikafta should only be used in patients who have moderate hepatic impairment if the benefits outweigh the risks. Patients who have severe hepatic impairment should not take Trikafta.
Vertex Pharmaceuticals plans to launch the product within a few weeks of approval at a list price of $311,000 per year.