Cystic fibrosis agent may pose cataract risk, FDA says

Children with cystic fibrosis who are taking ivacaftor (Kalydeco) may be at potential risk for cataracts, according to an FDA notification issued at the end of August.

“This potential safety concern is based on recent results from an animal study in juvenile rats that was conducted to support the treatment of young children less than 2 years of age with ivacaftor,” FDA officials said in its release. However, “there is uncertainty about the relevance of the risk to children, since there are differences in eye development between humans and rats.”

The label for ivacaftor has been updated to include information about cataract development from the study of the juvenile rats that were 7 to 35 days old and received 10 mg/kg or more daily, which is about one-tenth the maximum recommended human dose.

FDA is requiring that Vertex Pharmaceuticals, the manufacturer, conduct a clinical study in children up to 11 years of age who are being treated with ivacaftor. These children will be followed for 2 years and receive eye exams from an ophthalmologist every 6 months to assess visual acuity and cataracts/eye opacities.

In January 2012 FDA approved the CFTR protein potentiator for patients with cystic fibrosis age 6 years and older who have a G551D mutation.

“Until further information about these findings is known, it is recommended that cystic fibrosis patients with G551D mutation in the CFTR who are receiving Kalydeco continue treatment,” as reported in the release. “However, parents/caregivers are also encouraged to discuss the benefits and risks of Kalydeco treatment with their child’s healthcare professional.”