HIV has taught the pharmaceutical industry that the best way to fight an infectious virus that resists a single drug is to make a cocktail that attacks the virus in more than one way. Vertex Pharmaceuticals and its competitors are now following a similar formula with new therapies for hepatitis C.
Vertex, the Cambridge, MA-based company with operations in San Diego, offered a glimpse last week into its strategy for a two-drug combo that could significantly change hepatitis C treatment. If the company has mapped this out correctly, it could rid people of the virus while letting them ditch the detested standard therapies that force them to endure months of flu-like symptoms. I followed up last Friday to learn more from a conversation with Vertex’s chief medical officer, Bob Kauffman.
The big story from the past couple years at Vertex (NASDAQ: [[ticker:VRTX]]) is the development of its first-in-class protease inhibitor drug called telaprevir. This oral pill, taken two or three times a day, must be combined with the pegylated interferon alpha and ribavirin. It has excited researchers because it has been able to double the cure rate while shortening the course of therapy by half. That means that many more of 170 million people worldwide with chronic hepatitis C liver infections will be likely to seek out treatment, and be able to stand up to the side effects of standard therapy over a shorter period of time. If the ongoing clinical trials to test this idea are successful this year, Vertex could bring telaprevir to the market in 2011. U.S. sales alone could amount to more than $2 billion after a couple years, researchers say.
That will be headline news if and when it happens. But researchers around the world, and Vertex’s competitors, see even bigger advantages if someone can get rid of pegylated interferon alpha and ribavirin altogether. The vision is to combine a protease inhibitor like telaprevir with one or more other antiviral drugs that work differently, essentially blocking some of the escape routes that enable the virus to develop resistance to a single drug.
There are three other main therapeutic classes being tested in clinical trials—nucleoside polymerase inhibitors, non-nucleoside polymerase inhibitors, and NS5a inhibitors, Kauffman says. Vertex paid $375 million last year to acquire a small Canadian company, ViroChem Pharma, mainly to obtain a non-nucleoside polymerase inhibitor that Vertex thought would complement its own telaprevir. That drug, called VX-222, has shown promising antiviral punch in some small studies on its own, and now it is entering its first serious test in tandem with telaprevir in a clinical trial.
“It really became clear early on that these hepatitis C agents couldn’t really be given [as single agents] because of the virus’s ability to develop resistance,” Kauffman says. Combinations have long been thought to be the best way forward, and to get rid of the standard treatments. “That was the goal from the beginning,” Kauffman says.
Vertex spent the last year figuring out the right doses, and balance between the two drugs, that it thought would be ideal for a teleprevir/VX-222 combination trial. Last week, it unveiled
