SILVER SPRING, Md.—Merck's drug candidateVictrelis (boceprevir) secured U.S. Food and Drug Administration (FDA) approvalthis month, amking it the first hepatitis C drug to gain approval in 20 years.Victrelis is approved to treat adults with chronic hepatitis C who still retainsome liver function and who have either failed previous drug therapy or havenot undergone such treatment. The drug is approved for combined use withpeginterferon alfa and ribavirin.
"Victrelis is an important new advance for patients withhepatitis C," says Edward Cox, M.D., director in the Office of AntimicrobialProducts in the FDA's Center for Drug Evaluation and Research. "This newmedication provides an effective treatment for a serious disease, and offers agreater chance of cure for some patients' hepatitis C infection compared tocurrently available therapy."
Victrelis' safety and effectiveness were evaluated in twoPhase III clinical trials with 1,500 adult patients. In both trials, two-thirdsof patients who received Victrelis together with pegylated interferon andribavirin experienced a significantly increased sustained virologic response,meaning that the hepatitis C virus was not detected in the blood 24 weeks aftertreatment ended, compared to those who received pegylated interferon andribavirin alone, which is the current method of treatment. A sustainedvirologic response after treatment is completed suggests that the HCV infectionhas been cured. A sustained virologic response can result in decreased complicationsof liver disease, decreased cirrhosis (scarring of the liver), decreased ratesof liver cancer (hepatocellular carcinoma) and decreased mortality.
Victrelis is taken orally three times a day with food, andfalls into the class of drugs known as protease inhibitors, as it works bybinding to the hepatitis virus and preventing it from multiplying. The commonside effects reported from those taking Victrelis include nausea, headache,fatigue, low red blood cell count (anemia) and taste distortion (dysgeusia).
Hepatitis C is a contagious liver disease that can vary inintensity from an illness that lasts for a few weeks after infection (acutehepatitis C virus infection) to a lifelong illness that constantly attacks theliver (chronic hepatitis C virus infection). According to the U.S. Centers forDisease Control and Prevention (CDC), acute infection will lead to chronicinfection in approximately 75 to 85 percent of people who become infected withhepatitis C. The CDC notes that an estimated 3.2 million people in the U.S.have chronic hepatitis C, though numbers for this disease are difficult to pindown exactly since most people don't know they are infected since they do notfeel sick. Many people with hepatitis don't display any symptoms until liver damageoccurs, something that could take years. Hepatitis C is spread through theblood and can be transmitted by sharing needles with an infected person orbeing born to a mother with HCV. There is no vaccine for hepatitis C.
A majority of the liver transplants in the U.S. are requiredbecause of progressive liver disease caused by a hepatitis C infection. Somepeople suffering from chronic hepatitis C infection will develop cirrhosis, orscarring, of the liver after several years, which can lead to liver damage andcomplications such as jaundice, bleeding, infections, fluid accumulation in theabdomen or liver cancer.