Treatment of Chronic Delta Hepatitis With Lonafarnib

Chronic delta hepatitis is a serious form of chronic liver disease caused by infection with the hepatitis D virus (HDV), a small RNA virus that requires farnesylation of its major structural protein (HDV antigen) for replication. We propose to treat between 12 and 14 patients with chronic delta hepatitis using the farnesyltransferase inhibitor (FTI) lonafarnib for a duration of twenty-eight days. Farnesyltransferase inhibitors have not been used in the therapy of delta hepatitis. Patients with HBsAg and HDV RNA in serum, elevated aminotransferases, or moderate-to-severe chronic hepatitis and HDV antigen on liver biopsy will be enrolled. Before receiving therapy, patients will be monitored for at least three months with regular testing for alanine aminotransferase (ALT) levels and will undergo Clinical Center admission for medical evaluation and percutaneous liver biopsy. Two dosing groups of lonafarnib will be assessed, with a placebo cohort in each group. At each clinic visit, patients will be questioned about side effects and symptoms, undergo focused physical examination, and have blood drawn for complete blood counts, HDV RNA, and routine liver tests (including ALT, AST, alkaline phosphatase, direct and total bilirubin, and albumin). At two-week intervals, for a period of 28 days, patients will also be tested for HBsAg, anti-HBs, HBV DNA, and prothrombin time. At the end of 28 days of treatment, patients will undergo repeat physical examination, assessment of symptoms (using a symptom scale questionnaire), complete blood counts, routine liver tests, and hepatitis B and D viral markers. The primary therapeutic endpoint will be an improvement in quantitative serum HDV RNA levels after 28 days of lonafarnib therapy. The primary safety endpoint will be the ability to tolerate the drug at the prescribed dose for the 4 week duration. Several secondary endpoints will be measured, including side effects, ALT levels, and symptoms. Therapy will be stopped for intolerance to lonafarnib (which will be carefully defined). This study is designed as a phase 2a study assessing the safety, tolerance and antiviral activity of two dose levels of lonafarnib, a farnesyltransferase inhibitor.