Biotech Values

[mcbio]

Re: IDX136 vs. IDX316

Which IDIX protease inhibitor is better, IDX136 or IDX316?

[The following is reposted from the IDIX board in reply to “gym gravity.” The discussion stems from IDIX’s poster presentation on IDX136/IDX316 at EASL, which can be found in the first embedded link in #msg-37315636.]

[GG]: My guess is they favor IDX316 based on potency in the biochemical assay and longer pharmacokinetics in animal plasma.

[Dew]: I respectfully disagree because potency is not the issue here—both drugs are plenty potent and the determination of which one to bring forward ought to depend on tolerability and resistance.

The half-life is not a major issue for an HCV protease inhibitor as long as it’s suitable for BID dosing; both of these are, based on the preclinical data.

[GG]: IDX136 remains active against 4 mutations while IDX316 is active against 3.

[Dew]: This could be the decisive factor unless there is a material difference between the two drugs in tolerability. The rapidity with which mutations are generated is the Achilles heel of HCV PI’s, and hence you want the highest barrier to resistance you can get.

All told, I would say IDX136 has the edge based on the data to date.

I just listened to the IDIX presentation at the Morgan Stanley Healthcare Conference from Monday and it sounds like they have picked a PI to move forward from IDX136 and IDX316. They didn't identify which one it was but they indicated that the driving factor was "potency and once/day dosing." They further indicated that the ability to co-formulate with IDX184 in the future in once/day dosing was another driving factor. I assume they have chosen IDX316 given the references to potency and once/day dosing. The discussion is just after the 17-minute mark of the presentation.