Based on the published incidence, published regional populations, and estimated median life expectancies, we estimate the prevalence of PFIC together with BRIC to be approximately 8,000 to 10,000 patients in the U.S. and E.U. but we are not able to estimate the prevalence of PFIC or BRIC with precision. We estimate that there are approximately 3,000 to 4,000 PFIC patients in the U.S. and E.U. We also estimate that there are approximately 5,000 to 6,000 BRIC patients in the U.S. and E.U. We currently have not modeled other regional opportunities in Asia, the Middle East and Latin America. We are aware there may be higher prevalence of disease in some countries such as Saudi Arabia and Turkey. There are currently no drugs approved for the treatment of PFIC. First-line treatment for PFIC is typically off-label ursodeoxycholic acid, or UDCA, which is approved in the United States and elsewhere for the treatment of primary biliary cholangitis, or PBC. However, many PFIC patients do not respond well to UDCA, undergo partial external bile diversion, or PEBD, surgery and often require liver transplantation. PEBD surgery is a life-altering and undesirable procedure in which bile is drained outside the body to a stoma bag that must be worn by the patient 24 hours a day. |