WASHINGTON -- Indications for the cystic fibrosis drug combination tezacaftor/ivacaftor (Symdeko) now include children as young as age 6 with specific mutations in the CFTR gene, the FDA said Friday.
"Today's approval of Symdeko for children as young as 6 years old provides an important treatment option for younger patients, and also provides more context on the safety and dosing specific to this population," said Banu Karimi-Shah, MD, acting deputy director of the Division of Pulmonary, Allergy, and Rheumatology Products in the FDA's Center for Drug Evaluation and Research, in a statement.
The product -- which consists of a fixed-dose combination pill to be taken in the morning, plus a separate pill containing only ivacaftor to be taken in the evening -- was initially approved in February 2018 for adults and children as young as age 12 with cystic fibrosis and CFTR mutations that respond to the drugs.
Notably, the combination's effectiveness in children ages 6-12 was not tested directly. "The efficacy in patients ages 6 to 12 was extrapolated from patients age 12 years and older, with additional support from data in patients age 6 to 12 years," the FDA noted. Safety in the younger population was established from an open-label trial involving children in the 6-12 age range. Adverse effects were the same as those seen previously in older children.
Warnings on the tezacaftor/ivacaftor label include risk of cataracts in pediatric patients and a recommendation to monitor liver enzymes before and after initiating therapy. Patients should not combine the product with other agents such as St. John's wort that compete for CYP3A-mediated metabolism. Common adverse reactions include headache, nausea, sinus congestion, and dizziness.