The Medicines and Healthcare Products Regulatory Agency (MHRA) has today (15 November 2023) extended the license for the cystic fibrosis drugs Cafrio (ivacaftor, tezacaftor and elexacaftor) and Kalydeco (ivacaftor) for children aged two to five.
These drugs were already approved for use in the treatment of cystic fibrosis in patients six years of age and older with a common gene mutation, and today’s announcement expands that approval.
Given the unmet needs of children with cystic fibrosis, we prioritized evaluation of Cafrio and Kalydeco for this age range. As with all products, we will keep the safety of Kaftrio and Kalydeco under close review in this age range.”
Julian Beach, MHRA Interim Executive Director, Healthcare Quality and Access
Cystic fibrosis is an inherited condition that causes sticky mucus to build up in the lungs and digestive tract. It causes lung infections and indigestion. Symptoms usually begin in infancy and vary from child to child, but the condition gradually worsens over time, with the lungs and digestive system becoming increasingly damaged. More than 10,600 people are living with the condition in the UK.
Caftrio and Kalydeco are taken together as a long-term treatment for patients to manage the symptoms of cystic fibrosis. They are used to treat the disease in patients with at least one F508del mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. F508del is the most common cystic fibrosis causing mutation.
This gene is responsible for a protein that supports the movement of chloride in and out of our cells. Some mutations in the CFTR gene cause the CFTR protein to develop abnormally, causing reduced chloride movement in cells with cystic fibrosis.
The active ingredients in these treatments, ivacaftor, tezacaftor and elexacaftor, work by interacting with certain abnormal CFTR proteins, so they open more often to improve chloride movement in and out of cells.
Medications known as CFTR modulator therapy are available as sachets of granules to be mixed with 5ml of soft food and consumed immediately before or immediately after fatty meals/snacks.
For two- to five-year-olds weighing less than 14 kg, the recommended dose is one pack of Caftrio granules containing 60 mg ivacaftor, 40 mg tezacaftor and 80 mg elexacaftor, and one pack of Kalydeco granules containing 59 of 59 ivacaftor. In the evening, at least 12 hours apart.
The recommended dose for children aged two to five years weighing 14 kg or more is one pack of Caftrio granules containing 75mg ivacaftor, 50mg tezacaftor and 100mg elexacaftor given in the morning and another sachet of Kalydeco granules of 5mg ivacaftor taken in the evening, at least 12 hours apart. .
The extension of the existing approval to this age group is supported by evidence from studies of this drug combination in patients 12 years of age and older, and 24-week data from a Phase 3 clinical study in 75 patients aged two to five years with cystic fibrosis and at least one confirmed The diagnosis was F508del Mutation
In that study, patients continued their cystic fibrosis therapy, such as bronchodilators or inhaled antibiotics, but could be on any CFTR modulator therapy other than the study drug.
In the study, safety was assessed by monitoring drug side effects and treatment effects were evaluated using changes in sweat chloride concentration.
The study showed that treatment with Caftrio and Kalydeco was safe and well tolerated by patients, with a safety profile that was consistent with observations in older age groups.
In this study in two- to five-year-old children, sweat chloride concentration was reduced by 57.9 mmol/L during the study, and this effect was comparable to the effect on sweat chloride in older children and adults where clinical efficacy was demonstrated for this combination.
The most common side effects of the drug are a common cold, including sore throat and nasal congestion, headache, dizziness, diarrhea, abdominal pain, changes in the type of bacteria in the mucus, increased liver enzymes, and rash.
As with any medicine, the MHRA will keep the safety and effectiveness of both Caftrio and Kalydeco under close review. Anyone who suspects they are having side effects from these medicines is encouraged to speak to a doctor, pharmacist or nurse and report them directly to the Yellow Card Scheme, either via the website (https://yellowcard.mhra.gov.