Elexacaftor (VX-445) is primarily used in the treatment of cystic fibrosis, a genetic disorder that affects the lungs and digestive system. It is often combined with other drugs like tezacaftor and ivacaftor to enhance its effectiveness. This combination works by improving the function of the defective CFTR protein, which is responsible for the movement of salt and water in and out of cells. By correcting this protein's function, the treatment helps to reduce the buildup of thick mucus in the lungs, thereby improving respiratory function and overall quality of life for patients. It is particularly beneficial for individuals with specific mutations in the CFTR gene, such as the F508del mutation. The use of elexacaftor has shown significant improvements in lung function, reduced frequency of pulmonary exacerbations, and better nutritional outcomes in clinical trials.