Idenix Pharmaceuticals (IDIX)

[gofishmarko]

>> The benefit of ribavirin may not be all that complicated. Riba's main contribution is probably that it works well against mutant strains while NM283 works mostly against wild-type HCV. <<

If the only benefit of riba is on direct antiviral activity , that may be true. However , it seems to be widely acknowledged that riba reduces relapse rates , at least as regards usage in combo with ifn. That implies that if you look at two groups of patients , one group treated with ifn and the other with ifn/riba , and in which all patients become HCV-negative at week X and remain HCV-negative Y weeks until EOT , you will see a higher SVR rate in the combo group. Assuming this is true , this further implies an effect beyond one on direct antiviral activity. One MOA that has been proposed for this is the tendency of riba-treated patients to show a Th1-biased immune response as opposed to a less effective Th2-type response.

JP sort of hinted at this in the webcast while talking about the "magic" of ribavirin , when he lamented that although many patients in the nonresponder trial were HCV-neg for six months or more , none achieved SVR. I think it's possible that he and others at IDIX may have been truly surprised by this , but I question whether they should have been.