Federal health officials said Tuesday a highly anticipated hepatitis C drug from Vertex Pharmaceuticals successfully treats the majority of patients with the virus in less time than older medicines that have been used for 20 years.
The Food and Drug Administration posted its review of Vertex's telaprevir ahead of a meeting Thursday where outside experts will vote on the benefits of the experimental drug. On Wednesday the experts will review a similar drug from Merck & Co. Inc.
Both new drugs work by blocking the enzyme protease, which allows the hepatitis virus to reproduce. The new approach represents a breakthrough from older medicines, which are designed to help boost the immune system to fight hepatitis.
Like HIV drugs, the new drugs will be prescribed as part of a cocktail with the two older drugs to help lower viral levels.
"A drug like telaprevir does an amazing job clearing the virus, but there's a small portion that is just intrinsically less responsive and it's the job of the older drugs to clear up that mess that's left behind," said Dr. Camilla Graham, Vertex's vice president for global medical affairs.
The current two-drug treatment for the virus cures only about 40 percent of people and causes side effects like nausea, fatigue and vomiting.
FDA scientists said 79 percent of first-time hepatitis C patients taking telaprevir and the older medicines were cured, compared to 46 percent of those taking the older medications alone, according to Vertex's studies. Among patients who had already been treated for hepatitis C once, 65 percent achieved a cure after taking telaprevir, compared with 17 percent of those taking the older medications.
In general, telaprevir's cure rates are higher than those seen with Merck's boceprevir. The two drugs are expected to compete in a multibillion dollar global market.
Shares of Vertex Pharmaceuticals Inc. rose $5.96, or 12.4 percent, to $54 in midday trading.
Vertex's studies were designed to show that adding telaprevir to the older drug combination could cure most patients in six months _ cutting the standard treatment time in half and reducing exposure to negative side effects.
According to the FDA, 58 percent of new patients were eligible for this shorter treatment regimen based on reduced viral levels after four or 12 weeks. The FDA's review states that patients who have previously been treated for the disease should respond similarly.
FDA notes that the drug was significantly less effective for African Americans. The most common side effect with the drug was a skin rash and fatigue.
The agency will ask its panel to comment on those issues on Thursday. The FDA is not required to follow the advice of its panelists, though it usually does
Hepatitis C is a major cause of liver transplants, and it kills about 12,000 U.S. patients a year, a number expected to triple by 2030 as baby boomers succumb to the disease.
The disease is often associated with users of illegal injectable drugs like heroin, though it could also be picked up from blood transfusions before 1992, when testing of the blood supply began.
Most people with hepatitis C don't even know they have the virus until years later when liver damage has occurred, which can cause abdominal pain, fatigue, itching and dark urine.
Vertex Pharmaceuticals is based in Cambridge, Mass., and was founded in 1989 by a former Merck scientist. If approved, telaprevir would be the company's first commercialized product in the U.S. Vertex holds marketing rights for North America, while Johnson & Johnson will market the drug in other parts of the world.