Hepatitis C Virus - Current Research

Current Research

The study of HCV has been hampered by the narrow host range of HCV. The use of replicons has been successful but these have only been recently discovered. HCV, as with most RNA viruses, exists as a viral quasispecies, making it very difficult to isolate a single strain or receptor type for study.

Current research is focused on small-molecule inhibitors of the viral protease, RNA polymerase and other nonstructural genes. Two agents - Boceprevir by Merck and Telaprevir by Vertex Pharmaceuticals Inc - both inhibitors of NS3 protease were approved for use on May 13, 2011 and May 23, 2011 respectively.

A possible association between low Vitamin D levels and a poor response to treatment has been reported. In vitro work has shown that Vitamin D may be able to reduce viral replication. While this work looks promising the results of clinical trials are awaited.

Other agents that are under investigation include nucleoside/nucleotide analogue inhibitors and non nucleoside inhibitors of the RNA dependent RNA polymerase, inhibitors of nonstructural protein 5A and host targeted compounds such as cyclophilin inhibitors and silibinin.

A few researchers are looking into the benefits of using blood filtration, as an adjunct to the standard of care therapy, to increase the cure rate with chronic hepatitis C patients, and patients in difficult-to-treat states. Cure rate is defined as a sustained viral response measured 6 months after the end of treatment. It has been shown that by reducing the viral load during the initial onset of the ribavirin and pegylated interferon therapy has greatly enhanced the efficacy of the therapy and increase the cure rate without adding additional drugs and their associated side effects.

Recently Asahi Kasei Medical in Japan has demonstrated that by using a double-filtration plasmapheresis,(DFPP) technique, a simple physical reduction in circulating HCV using a 1-week pretreatment increased the cure rate for treatment-naïve type 1 HCV patients from 50% (controls) to 78% (treated). For previous nonresponders, the cure rate increased from 30% to 71%. This new adjunct treatment, called VRAD has been approved and is currently being administered in Japan. It is also covered by the Japan National Health Insurance Program.

Aethlon Medical is also pursuing blood filtration to enhance the current standard of care regimen. Aethlon uses a lectin affinity plasmapheresis or(LAP) method to filter out the HCV virus from the blood. The key advantage of LAP over DFPP is that it selectively targets the virus by mimicking the body's own immune response. It uses the viruses affinity to certain proteins to selectively remove the virus from the blood stream. DFPP filters based on size and therefore will remove other components of the blood along with the virus. LAP is safer and more effective at removing the virus than DFPP and has shown to reduce viral load by 57% - 82% with only 3 treatments in 2 weeks time. Currently Aethlon's Hemopurifier®, a filtration system using LAP, is the subject of a human clinical study in India to evaluate its ability to accelerate viral load depletion when utilized in combination with the current HCV standard of care drug therapy.