Ivacaftor Therapy in CF Patients: Single Center Experience

Ivacaftor is the first novel cystic fibrosis pharmaceutical that acts at the molecular level to potentiate cystic fibrosis transmembrane conductance regulator (CFTR) function and was first approved for clinical use in 2012. We are sharing our single center experience of five patients: four from pediatric age group and one adult patient. All patients had both subjective and objective improvements in their health. Despite established lung disease, our patients had significant improvement in both their FEV1 (forced expiratory volume in 1 second) and FE and BMI (body mass index). Larger studies demonstrated only 6.7% improvement in mean FEV1 after starting Ivacaftor therapy but their patient population had normal lung function to begin with. In contrast our case series demonstrates that, in patients with established lung disease and diminished lung function, Ivacaftor can be expected to result in much higher recovery in lung function. Mean FEV1 improved by 35% in our case series. Ivacaftor is extremely expensive, costing $300,000 per patient per year requiring lifelong therapy, hence requiring prior authorizations from most third-party payers in the USA. The knowledge shared from our experience will be useful for other clinicians to petition healthcare policymakers on behalf of their patients. 1. Introduction Cystic fibrosis (CF) is the most common life-threatening autosomal recessive disease in the USA [1]. There is a wide variety of gene sequences in cystic fibrosis and more than 1900 CF mutations have been identified [2]. Although daily airway clearance therapies and pancreatic enzyme replacement are keys to CF management, the introduction of Pulmozyme and the introduction of inhaled antibiotics were two milestones in CF management and have become routine care in established lung disease in CF patients. However, there was no known medication that could correct this disease and its underlying molecular defect until recently. Ivacaftor, also known as Kalydeco, is the first marketed drug which restores the function of the cystic fibrosis transmembrane conductance regulator (CFTR). It was approved by the United States Food and Drug Administration (FDA) in January 2012 for treating cystic fibrosis patients with G551D mutation, older than six years. It has shown to be effective as evidenced by reduction in the sweat chloride content of the subjects as well as by the improvement in FEV1 up to 10 percent [3]. Due to its prohibitive cost (approximately $300,000/patient/year), Ivacaftor therapy requires prior authorization from insurers. These insurers often rely