There is more than one race going on. In addition to the race to get the first all-oral Hep C GT1 treatment to market, Vertex is racing to simplify and cut the treatment times for the current Incivek/interferon/ribavirin Hep C GT1 treatment. Long before any all-oral treatment for GT1 is available, Vertex will have cut the Incivek based GT1 treatment from three times a day dosing to twice a day and the treatment duration will be cut to just 12 weeks. Pharmasset's obsession with interferon intolerance leads me to believe that their game plan will be to market a less effective all-oral therapy for GT1 patients and then use a very broad definition for interferon intolerance that includes nearly every patient with Hep C GT1. Then the patients and their doctors will have to decide if they want a higher cure rate or a few less side effects.
The FDA, when considering approval of new antiviral agents, would need to redefine what is an acceptable SVR or cure rate for each subset of chronic hep C patients, given the variablitlity of reponse based on genotype, IL28B status, race, severity of liver damage, coinfection with HIV, or hep C in liver transplants etc., given the higher cure rates established with the approved PIs. Clearly IFN free regimens would be preferred by patients for fewer side effects and is "the holy grail" for all the players in this race for an all oral treatment. But SVR is still the primary objective for the patients who if they fail treatment, continue to have a lethal disease. Vertex has over the past 6 years completed or is in the proces of completing testing of TVR in various combination therapy in not just GT 1 naives and prior GT 1 SOC treatment failures, but in the various difficult to treat subsets of GT 1 patients listed above. Pharmasett, suggests it's agent based on success in treating the easier to treat GT2 and 3 patients should get a broad approval for all hep C patients regardless of genotype including the difficult to treat GT1 subsets. Yet rather than test each subset as a separate trial as Vertex is doing, they are proposing to test a GT 1 group they define as "IFN intolerant" and evidently cannot clearly and consistently define what that term means in their last conference call. The FDA will likely only allow a label to approve treatment of those subsets of hepatitis C which have clinical trial results with SVR results comparable to treamtment already in use. Pharmasett should not be allowed to the the "fear factor" of adverse effects to deter patients and prescribers from using the most effective treatment availiable for a this lethal disease. Marketing a less effective drug as preferable because it has a lower incidence of rash is not working out so well for Merck's Victrellis.
"Pharmasett, suggests it's agent based on success in treating the easier to treat GT2 and 3 patients should get a broad approval for all hep C patients regardless of genotype including the difficult to treat GT1 subsets."
VRUS did more mid-stage testing of GT1 patients than GT2/GT3. Are you aware that the phase 2 ELECTRON study in GT1 patients is ongoing? Are you aware that one of the two GT1 oral arms is in null-responders? Do you think interferon-intolerant patients would be easier to treat than the standard treatment naive patient? If so why?