Study of the Efficacy and Safety of Lonafarnib / Ritonavir With and Without Pegylated Interferon -Alfa-2a

This partially double-blind, randomized study will employ a matrix (factorial) design to evaluate the efficacy and safety of LNF 50 mg/RTV 100 mg twice per day (BID) with and without PEG IFN-alfa-2a 180 mcg once-weekly (QW) for 48 weeks compared to no treatment (placebo LNF and placebo RTV) in patients chronically infected with hepatitis delta virus (HDV) and receiving anti-HBV (hepatitis B virus) nucleos(t)ide maintenance therapy. Approximately 400 patients will be randomized with an allocation ratio of 7:5:2:2 All patients will receive/maintain background anti-HBV nucleos(t)ide therapy with entecavir or tenofovir for at least 12 weeks prior to initiating study therapy. All patients who complete 48 weeks of treatment will have a liver biopsy for histology assessment at EOT and will be followed for an additional 24 weeks off study treatment.