In the mid 1970s, Harvey J. Alter, Chief of the Infectious Disease Section in the Department of Transfusion Medicine at the National Institutes of Health, and his research team demonstrated that most post-transfusion hepatitis cases were not due to hepatitis A or B viruses. Despite this discovery, international research efforts to identify the virus, initially called ''non-A, non-B hepatitis'' (NANBH), failed for the next decade. In 1987, Michael Houghton, Qui-Lim Choo, and George Kuo at Chiron Corporation, collaborating with Dr. D.W. Bradley from CDC, utilized a novel molecular cloning approach to identify the unknown organism. In 1988, the virus was confirmed by Alter by verifying its presence in a panel of NANBH specimens. In April of 1989, the discovery of the virus, re-named hepatitis C virus (HCV), was published in two articles in the journal ''Science''.
Chiron filed for several patents on the virus and its diagnosis. A competing patent application by the CDC was dropped in 1990 after Chiron paid $1.9 million to the CDC and $337,500 to Bradley. In 1994 Bradley sued Chiron, seeking to invalidate the patent, have himself included as a co-inventor, and receive damages and royalty income. He dropped the suit in 1998 after losing before an appeals court.
In 2000, Drs. Alter and Houghton were honored with the Lasker Award for Clinical Medical Research for "pioneering work leading to the discovery of the virus that causes hepatitis C and the development of screening methods that reduced the risk of blood transfusion-associated hepatitis in the U.S. from 30% in 1970 to virtually zero in 2000."
In 2004 Chiron held 100 patents in 20 countries related to hepatitis C and had successfully sued many companies for infringement. Scientists and competitors have complained that the company hinders the fight against hepatitis C by demanding too much money for its technology. is currently in Phase 3 Trials.
One protease inhibitor, ''BILN 2061'', had to be discontinued due to safety problems early in the clinical testing. Some more modern new drugs that provide some support in treating HCV are ''Albuferon'', ''Zadaxin'',. Antisense phosphorothioate oligos have been targeted to hepatitis C. Antisense Morpholino oligos have shown promise in preclinical studies however, they were found to cause a limited viral load reduction.
Immunoglobulins against the hepatitis C virus exist and newer types are under development. Thus far, their roles have been unclear as they have not been shown to help in clearing chronic infection or in the prevention of infection with acute exposures (e.g. needlesticks). They do have a limited role in transplant patients.
In addition to the standard treatment with interferon and ribavirin, some studies have shown higher success rates when the antiviral drug amantadine (Symmetrel) is added to the regimen. Sometimes called "triple therapy", it involves the addition of 100 mg of amantadine twice a day. Studies indicate that this may be especially helpful for "nonresponders" - patients who have not been successful in previous treatments using interferon and ribavirin only. Currently, amantadine is not approved for treatment of Hepatitis C, and studies are ongoing to determine when it is most likely to benefit the patient and when it is a risk due to their liver deterioration.
Among the more novel treatments under development is the Hemopurifier(R), a first-in-class medical device that selectively removes infectious viruses and immunosuppressive proteins from the bloodstream. In HCV care, the Hemopurifier(R) inhibits viral replication through selective adsorption of circulating HCV and augments the immune response by removing toxic proteins shed from HCV to kill-off immune cells. Recent clinical data validates the mechanical removal of HCV through blood filtration in combination with SOC therapy can increase HCV cure rates by greater than 50%. Studies are ongoing at the Fortis Hospital in New Delhi, India.
Further Reading
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