Tuesday, May 25, 2010

Vertex Reports Strong Late-Stage Hepatitis-C Drug Data

In a report by the Wall Street Journal, Vertex reports some nice results from the first of three highly anticipated anti-HCV drug trials. The study included 1095 people with HCV genotype 1 which is the most common form of the virus found in the U.S. and Europe. Genotype 1 is also the most difficult to treat and has the lowest success rate of any of the 11 major types.

The data shows that 75% of subjects taking teleprevir (a protease inhibitor) for 12 weeks along with standard therapy for 12 weeks + an additional 12 weeks (24 total weeks of standard therapy*) achieved a sustained virological response (SVR) which is not complete elimination of the virus but is defined as the suppression of virus to undetectable levels. As compared to the control subjects who recieved the standard therapy*, achieved an SVR of 44%. Unfortunately, it is expected that the cost for the drug regimen will cost in the 10's of thousands of dollars. The other important thing to remember is like HIV, HCV is an RNA virus which means rapid mutation, which means rapid selection for resistance to drugs. It is a step in the right direction, and as more drugs are synthesized, cocktails can be changed to adapt to the mutating virus.

These findings are key for 3 reasons:
1. Increase of 31% in the treated subjects of SVR
2. Treatment is shortened from 48 to 24 weeks
3. Very minimal side effects (rash, anemia)

The results from 2 other large trials will be reported by Vertex in the 3rd quarter. Vertex plans on marketing the drug by itself, with overseas help form Johnson & Johnson. Numerous other companies are working on HCV therapeutics including Bristol-Myers Squibb Co., Gilead Sciences Inc., Roche Holding AG, and Abbott Labs.

The major alternative therapy for HCV is milk thistle (silymarin) may have various benefits to the liver, such as:

•Promoting the growth of liver cells
•Fighting oxidation and oxidative stress
•Inhibiting inflammation

Thus far, few scientific studies have found evidence that milk thistle helps in treating HCV. Some studies showed a possible benefit, while other studies have not.

Polyak SJ, Morishima C, Hawke R, Antiviral effects of silymarin against hepatitis C: the jury is still out., Hepatology (Baltimore, Md.) 48: 1, 345-6, Jul, 2008.

* Standard therapy is currently Pegylated interferon-alpha-2a or Pegylated interferon-alpha-2b (brand names Pegasys or PEG-Intron) and the antiviral drug ribavirin for 48 weeks

Lance D. Presser has a PhD in Microbiology & Immunology, and is a Public Health Laboratorian.

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