Eiger BioPharmaceuticals announced that studies from its Hepatitis Delta Virus (HDV) development program will be presented at the upcoming European Association for the Study of the Liver (EASL) conference April 13-17 in Barcelona, Spain.

Also, interim results from the LOWR HDV – 2 (LOnafarnib With Ritonavir in Hepatitis Delta Virus – 2) Phase 2 clinical trial in patients infected with HDV will be presented at the Hepatitis Delta International Network meeting at EASL.

LOWR HDV – 2 is an open-label, dose-ranging trial to evaluate the safety and efficacy of lonafarnib with ritonavir boosting in patients chronically infected with HDV. The study’s primary endpoint is the decline of HDV RNA from baseline to end of treatment with lonafarnib and ritonavir in a time frame of 12 to 24 weeks.

To date, about 40 patients infected with HDV were enrolled in the trial and randomized in nine different dosing groups of lonafarnib plus ritonavir. Lonafarnib doses range from 150 mg once a day to 25 mg twice a day. In the trial, all patients were measured for biochemical parameters, quantitative serum HDV RNA viral loads, and lonafarnib drug levels.

As of last month, more than 30 patients with HDV had been treated in LOWR HDV-2 for at least 12 weeks.

According to a press release, the abstracts to be presented at the EASL include:

• Yurdaydin, C. et al; “Exploring optimal dosing of lonafarnib with ritonavir for the treatment of chronic delta hepatitis — results from the on-going LOWR HDV – 2 study.” Oral Presentation, Hepatitis Delta International Network (HDIN) – April 13, 2016; 4:15-4:30 pm.

• Dahari, H. et al; “Hepatitis delta virus (HDV) kinetics under the prenylation inhibitor lonafarnib suggest HDV-mediated suppression of the HBV replication.” Poster Presentation FRI-111 – April 15, 2016.

• Dahari, H. et al; “Pharmacokinetics and pharmacodynamics modeling of lonafarnib in patients with chronic hepatitis delta virus infection.” Poster Presentation FRI-115 – April 15, 2016.

Hepatitis D (hepatitis delta) is caused by the hepatitis D virus (HDV), a small spherical enveloped RNA virus, one of five known hepatitis viruses: A, B,C, D, and E. HDV is considered to be a subviral satellite because it can only propagate in the presence of the hepatitis B virus (HBV). HDV can be transmitted by simultaneous infection with HBV (co-infection) or superimposed on chronic hepatitis B or hepatitis B carrier state (superinfection).

Lonafarnib is an orally active agent that targets the enzyme farnesyltransferase, a molecule involved in modification of proteins through a process called prenylation. Lonafarnib inhibits the prenylation step of HDV replication inside liver cells and blocks the virus life cycle at the stage of assembly.