Positive Tests Results for New Drugs Against Hepatitis C
Improved Screening for Hepatitis C Reflects Physicians' Optimism New Drugs Effective Against Hepatitis B, But Patient Selection Necessary
MILAN, April 25 /PRNewswire/ -- Scientists presenting at today's sessions of the 43rd Annual Meeting of the European Association for the Study of the Liver (EASL) reported encouraging findings regarding the potential efficacy of treatment strategies using new drugs designed to combat hepatitis B and C.
Notable progress has been made in clarifying the structure of the hepatitis C virus (HCV), leading to the development of new experimental drugs such as protease inhibitors and polymerase inhibitors, drugs that inhibit virus production. Some of these drugs have been extensively tested and some are currently in phase II trials. Phase III trials are planned. Based on results to date, it is clear that these drugs can be highly effective in combination with pegylated interferon and ribavirin. Novel anti-viral approaches at the preclinical developmental stage will also be presented.
An important trend in HCV has emerged in the past 5 years across many parts of Europe. In the past, cases of chronic hepatitis C often went undiagnosed because physicians assumed that the HCV regimen involved severe side effects and was destined to fail in most cases. Now, typically, when physicians see patients with even minor alterations of liver function tests, they then test for HCV. This is because they have been convinced that these patients can be successfully treated. Ironically, a new problem arises... According to Dr. Antonio Craxi, Professor of Gastroenterology and Internal Medicine at the University of Palermo, Italy, "Many physicians now have unreasonably optimistic expectations. Fifty percent of patients - generally those with the most severe disease -- will fail to respond to current therapy. They have more fibrosis, more advanced liver disease, more progressive conditions. The new small molecules, when combined with interferon and ribavirin may control their disease in a substantial number of cases. Future drugs will hopefully be more effective. And in several years combinations of 2 or 3 small inhibitor molecules may be administered without pegylated interferon. This is not feasible at the moment."
There are now new, tested molecules that are effective in obtaining viral suppression in hepatitis B virus (HBV). When used in HBV, these new agents have a strong suppressive effect... but none can entirely eradicate the hepatitis B virus. Once the HBV infection is established, it has to be treated for many years... maybe for the patient's lifetime. A new problem then arises... each drug is only licensed for use in monotherapy. But when used as a single therapy, drug resistance will eventually occur. As a result, what physicians are currently doing is treating a large number of patients with the risk of selecting resistant mutations that will eventually spread in the exposed population. Thus they are treating HBV effectively in the short-term but may create a long-term problem. For this reason, future development will likely involve combinations of these molecules.
The great unanswered HBV question at the moment is who should be treated? Because HBV treatment only contains rather than eliminates viral replication, once treatment stops, viral rebound can occur in a matter of days. So treatment has to be restarted, and continued for life. Currently, it is only feasible to treat those patients with severe progressive HBV, to prevent eventual cirrhosis and hepatocellular carcinoma. It is impractical to treat someone with HBV who is simply a healthy carrier, both because of the cost and because suppressing their viral infection may increase the likelihood of inducing a problematic mutation.
The European Association for the Study of the Liver (EASL) aims to promote investigation into liver disease and improve the treatments that currently exist for these conditions. The association, through its annual meetings, seeks to inform and educate both the scientific community as well as society in general about the increasing occurrence of liver diseases along with the importance of understanding these conditions in order to treat and prevent them. Since its creation in 1966, the EASL congress has been hosted in 20 different European countries. Currently the association has over 1400 members and the annual congress attracts over 6000 delegates from over 65 countries each year.
|SOURCE EASL - European Association for the Study of the Liver|
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