The U.S. FDA declined to approve Gilead Sciences Inc.’s Hepcludex (bulevirtide), issuing a complete response letter (CRL) citing manufacturing and delivery concerns for the antiviral aimed at treating confirmed chronic hepatitis delta virus (HDV) infection in adults with compensated liver disease. Acquired in Gilead’s 2021 buyout of Myr GmbH, Hepcludex received conditional approval from the European Commission in 2020 and would have been the first drug cleared for HDV in the U.S. Its delay, however, could give a boost to Eiger Biopharmaceuticals Inc., which is expected to report phase III data for lonafarnib by the end of 2022.