CSL Behring’s expensive hemophilia B gene therapy is to be reimbursed by the U.K. National Health Service, after the company agreed to an outcomes-based payment scheme. The therapy, Hemgenix (etranacogene dezaparvovec), which has a U.K. list price of £2.6 million (US$3.3 million), was approved under a managed access scheme, in which data will be collected over five years to enable both the long-term effectiveness, and any adverse liver toxicity caused by the transgene, to be monitored.