Vertex Nears Hit or Miss

For now, let's focus on PROVE 1, since that's the study that will soon yield some important data. The study has enrolled 260 patients spread across four arms:

• Arm 1: 12 weeks of telaprevir plus 12 weeks of alpha interferon and ribavirin (which I'll now refer to by its shorthand, PEG-IFN/RBV)

• Arm 2: 12 weeks of telaprevir plus 24 weeks of PEG-IFN/RBV

• Arm 3: 12 weeks of telaprevir plus 48 weeks of PEG-IFN/RBV

• Arm 4: A "control" or comparison treatment of 48 weeks of PEG-IFN/RBV (no telaprevir).

The most important data coming from this trial will be "cure" rates, defined as the number of patients in which the level of hepatitis C virus becomes undetectable, as measured by a highly sensitive blood test. In medical parlance, this is known as the rate of "sustained virologic response," or SVR, and it is typically assessed six months after the end of treatment.

In PROVE 1, all patients have completed their 12 weeks of telaprevir dosing. Arm 1 patients are off treatment altogether (having also finished their 12 weeks of PEG-IFN/RBV), while patients in Arms 2, 3 and 4 continue to get PEG-IFN/RBV.

Vertex's stated intent is to use medical meetings as the forum for the release of clinical data, as opposed to simply issuing press releases. The first likely opportunity, then, is the European Association for the Study of Liver Disease, being held April 11 to April 15 in Barcelona. At this meeting, we're likely to get an interim update on treated patients, which will include some shorter-term measure of SVR, or cure, rates.