Novartis announced that a phase II study with the first-in-class antiviral DEB025 (alisporivir) met its primary endpoint for achieving viral cure (24 weeks after stopping treatment) in 76% of patients with chronic hepatitis C. The study involved nearly 300 previously untreated patients infected with the most common form of hepatitis C virus (HCV), the genotype 1 (G1).

The data were presented t the European Association for the Study of the Liver (EASL) congress in Berlin, Germany. The findings show that 76% of G1 chronic hepatitis C patients treated with DEB025 plus standard of care (pegylated-interferon alfa 2a/ribavirin) achieved superior viral cure (known as sustained viral response, or SVR) compared to 55% of patients on standard of care alone (p=0.008). Treatment with DEB025 demonstrated a low incidence of adverse events, with discontinuation rates comparable between treatment groups.

"Hepatitis C is difficult to treat and current therapies are only effective in about half of patients infected with the most prevalent genotype of HCV," said Stefan Zeuzem, Professor of Medicine at the Goethe University Hospital in Frankfurt, Germany, and the study's principal investigator. "These results are exciting because a large majority of patients achieved sustained viral response with DEB025, with some who also benefited from a shorter duration of treatment compared to standard therapy."

DEB025 is the first in a new class of drugs called cyclophilin inhibitors. Unlike other compounds in development that target the virus directly, DEB025 is a host targeting antiviral (HTA) that targets so-called host proteins which are essential for the replication of HCV. As these proteins play a key role in the replication of all types of HCV, DEB025 may offer an effective treatment option for a broad range of HCV forms. In other clinical trials, DEB025 has also shown effective antiviral activity against other common HCV genotypes (G2, G3 and G4).

"There is a critical need for more effective drugs to treat chronic hepatitis C, and Novartis is dedicated to developing medicines that will reduce the burden of this disease for patients and physicians," said Trevor Mundel, MD, Global Head of Development at Novartis Pharma AG. "DEB025 has a new mode of action that may stop the virus from replicating and could reshape the future approach to treatment of hepatitis C."

More than 170 million people worldwide are infected with HCV, which can cause serious liver disease leading to cirrhosis, liver cancer, and in some cases death. HCV is a blood borne virus that predominantly affects the liver. As an RNA (ribonucleic acid) virus, it mutates much more than DNA (deoxyribonucleic acid) viruses. This ability to change makes it harder for the immune system to clear (or eliminate) the virus. There are six major variations of HCV, known as genotypes and labelled from G1 to G6.

The study presented at EASL was a 48-week, global, double-blind, randomized, placebo-controlled trial in G1 treatment-naïve chronic hepatitis C patients. It evaluated the efficacy and safety of DEB025 combined with pegylated-interferon alfa 2a/ribavirin (PegIFN/RBV) vs. PegIFN/RBV alone. The primary endpoint was sustained viral response after 24 weeks (SVR24).

Transient and reversible increase in bilirubin was observed in association with the initial DEB025 loading dose. A small proportion of patients (4.2%) had a transient increase in bilirubin more than five times the upper limit of normal (ULN), but this was not associated with liver damage.

A pivotal phase III study with DEB025 commenced recently to evaluate the efficacy and safety of DEB025 combined with standard of care and enrolling previously untreated HCV G1 patients. Other phase II studies are ongoing in other patient populations i.e., G1 treatment-experienced patients and G2 and G3 treatment-naive patients.

Novartis in-licensed DEB025 from Debiopharm Group, an independent biopharmaceuticals company based in Switzerland, under an agreement which gives Novartis exclusive worldwide development, manufacturing and marketing rights (excluding Japan).