>>> BUT, if combination therapy gains traction (and it sure looks like all 3 companies think it will based on the series of phase 3/4s out there), then it really will boil down to which nucleoside/nucleotide combo gives the best bang for the buck.. <<<
Agreed. Combo therapies could eventually re-sort the sales leaders in HBV drugs in ways that are hard to predict right now. Substandard monotherapy drugs like lamivudine ( vs. telbivudine and entecavir )and adefovir ( vs. tenofovir ) may even capture surprising market shares. The only downside to using a cheap combo first ( say , lam plus tenofovir or adefovir plus telbivudine ), assuming they provide rapid and sustained viral suppression , is the extent to which the patterns of eventual resistance to the combo hobbles follow-on tx. Although I expect tenofovir to displace adefovir as monotherapy , I wouldn't be surprised if it hangs on as a player in combos , at a lower price point , since it seems that the cross-resistance patterns between adefovir and tenofovir might not be as troublesome as one might expect based on structural similarities.
From the perspective of investing in IDIX , the combo tx. scenario will not fully play out until well after the standstill agreement date passes , while IDIX share price in the more near term seems sensitive to the slow ramp in Tyzeka sales. Having Anna Lok say that Tyzeka has "a limited role in HBV monotherapy" , just a few months ago , suggests to me that Tyzeka sales are likely to disappoint for quite a while yet , and that NVS , should they choose , will be able to buy the balance of IDIX at a price not very far removed from the current price.
