been treated for hepatitis C infections, just like the earlier trial. The study, which enrolled 500 patients, is also looking to see how many clinical cures it can generate, and whether there’s any benefit in subjecting patients to the standard 48-week course of therapy, or whether they do just as well in half the time, Kauffman says. “It should validate that 24 weeks is enough,” Kauffman says.
The third study, called “Realize,” is important for strategic and competitive reasons. This trial enrolled 663 patients who had previously been treated for hepatitis C, but weren’t cured. Vertex has shown some promising results in this tough-to-treat patient population in the past, which is the sort of data that can really give physicians confidence in the drug’s punch. Vertex has taken care to stratify this study into three different kinds of patients—those who benefitted for a while but relapsed, those who only partially responded to prior therapy, and those who never really benefitted at all. Patients will get telaprevir in addition to the standard treatment, or just the standard stuff, for a total of 48 weeks.
As I described back in September 2008, this study is one of the key ways that Vertex seeks to differentiate itself from a competitors that are following fast—Merck’s boceprevir.
Kauffman declined to speculate on how high the clinical cure rates will need to be for Vertex to declare victory. Last October, Vertex presented results from patients who failed prior therapy, which demonstrated telaprevir could induce cure rates between 55 percent and 90 percent. Vertex said back in April 2008, before it invested in the pivotal round of telaprevir trials, that between 61 percent and 68 percent of treatment-naïve patients were clinically cured in the smaller trials (Prove 1 and Prove 2).
After the past two years of recruiting patients, supplying the clinical sites with experimental drugs, monitoring the sites to make sure they follow the study protocol, and gathering all the data, you could say the expectations are high for this study. Wall Street, after all, is giving Vertex that $7.5 billion market valuation on anticipation of telaprevir’s sales trajectory more than any other factor. If the pivotal studies confirm the smaller trials—which is never a given in drug development—you will probably hear the victory whoops skimming all the way across the Charles River from Vertex headquarters in Cambridge.
“Phase III is the ultimate confirmation,” Kauffman says. “They are the largest and most definitive studies. It’s a very important time for us at the company now.”
