Drugs Xagena
Kalydeco ( Ivacaftor ) is the first medicine to treat the underlying cause of cystic fibrosis in people with specific mutations in the CFTR gene.
Known as a CFTR potentiator, Ivacaftor is an oral medicine that aims to help the CFTR protein function more normally once it reaches the cell surface, to help hydrate and clear mucus from the airways.
Kalydeco ( 150mg, q12h ) was first approved by the Food and Drug Administration ( FDA ) in January 2012 for use in people with cystic fibrosis ages 6 and older who have at least one copy of the G551D mutation and in February 2014 for use in people with cystic fibrosis ages 6 and older who have one of the following additional CFTR mutations: G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P or G1349D.
In the European Union, Kalydeco was approved in July 2012 for use in people with cystic fibrosis ages 6 and older who have at least one copy of the G551D mutation and in July 2014 for use in people with cystic fibrosis ages 6 and older who have one of eight additional gating mutations, including G178R, S549N, S549R, G551S, G1244E, S1251N, S1255P or G1349D.
Ivacaftor is not effective in patients with cystic fibrosis with 2 copies of the F508del mutation ( F508del/F508del ) in the CFTR gene.
The safety and efficacy of Ivacaftor in children with cystic fibrosis younger than 6 years of age have not been established.
Important safety information
Elevated liver enzymes ( transaminases; ALT and AST ) have been reported in patients receiving Ivacaftor. It is recommended that ALT and AST be assessed prior to initiating Ivacaftor, every 3 months during the first year of treatment, and annually thereafter.
Patients who develop increased transaminase levels should be closely monitored until the abnormalities resolve. Dosing should be interrupted in patients with ALT or AST of greater than 5 times the upper limit of normal.
Following resolution of transaminase elevations, consider the benefits and risks of resuming Ivacaftor dosing.
Use of Ivacaftor with medicines that are strong CYP3A inducers, such as the antibiotics Rifampin and Rifabutin; seizure medications ( Phenobarbital, Carbamazepine, or Phenytoin ); and the herbal supplement St. John's Wort, substantially decreases exposure of Ivacaftor and may diminish effectiveness. Therefore, co-administration is not recommended.
The dose of Ivacaftor must be adjusted when used concomitantly with strong and moderate CYP3A inhibitors or when used in patients with moderate or severe hepatic disease.
Ivacaftor can cause serious adverse reactions including abdominal pain and high liver enzymes in the blood. The most common side effects associated with Ivacaftor include headache; upper respiratory tract infection ( the common cold ), including sore throat, nasal or sinus congestion, and runny nose; abdominal pain; diarrhea; rash; and dizziness.
Cystic fibrosis
Cystic fibrosis is a rare, life-shortening genetic disease affecting approximately 75,000 people in North America, Europe and Australia. Today, the median predicted age of survival for a person with cystic fibrosis is between 34 and 47 years, but the median age of death remains in the mid-20s.
Cystic fibrosis is caused by a defective or missing CFTR protein resulting from mutations in the CFTR gene. Children must inherit two defective CFTR genes, one from each parent, to have cystic fibrosis.
There are more than 1,900 known mutations in the CFTR gene. Some of these mutations, which can be determined by a genetic, or genotyping test, lead to cystic fibrosis by creating non-working or too few CFTR protein at the cell surface. The defective function or absence of CFTR proteins in people with cystic fibrosis results in poor flow of salt and water into and out of the cell in a number of organs, including the lungs. This leads to the buildup of abnormally thick, sticky mucus that can cause chronic lung infections and progressive lung damage. ( Xagena )
Source: Vertex Pharmaceuticals, 2014
XagenaMedicine_2014
