Replies to post #1400 on Idenix Pharmaceuticals (IDIX)

[DewDiligence]

Good post—you covered a lot of ground. We’re on the same wavelength about Hepsera: Viread will make it obsolete.

If Ns+Nt combination therapy works, Viread will have the Nt side locked up; the contest will be between Tyzeka, Baraclude, and perhaps Clevudine on the Ns side.

I’ve yet to see anything to convince me that Tyzeka won’t eventually garner a 33% molecule share of the overall HBV market. If it can do that, IDIX’s 50% stake in the U.S. and western Europe and royalties in the rest of the world will generate some serious cash flow.

[gofishmarko]

>>> 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.

[DewDiligence]

>BMY and IDIX/NVS are literally neck and neck in tenofovir combination studies, having begun recruitment within a couple months of one another<

But see the comments in msg #1742 – these studies will be almost impossible to compare because they are in different disease settings.