Replies to post #95179 on Biotech Values

[DewDiligence]

Update on IDIX/GSK’s IDX899 (a/k/a GSK2248761):

GSK has evidently decided to make the phase-2b trial of IDX899 in the second-line setting a nuke-sparing trial; this effectively combines two planned phase-2b trials into one by testing cocktails consisting of a non-nuke, a PI, and integrase inhibitor without a nuke: IDX899+Prezista+Isentress vs Intelence+Prezista+Isentress:

http://clinicaltrials.gov/ct2/show/NCT01199731

The trial, called SONNET, has not yet started recruiting patients, but IDIX is due a significant milestone payment from GSK when the first patient is enrolled—my guess is $12.5M (see #msg-49743057).

SONNET has 50 patients in each of three arms: IDX899 200mg BID, IDX899 100mg BID, and Intelence (as prescribed in FDA label). All patients must have failed a prior HIV regimen including a non-nuke (typically Sustiva).

Based on 16-week data from the two IDX899 arms, the preferred dose of IDX899 will be selected and patients in the non-preferred IDX899 arm will switch to the preferred IDX899 dose after 24 weeks. The comparison of IDX899 to Intelence will then continue until 48 weeks. The randomization of patients to one of the two IDX899 arms is blinded, but the IDX899 vs Intelence comparison is open-label.

Viral load will be measured at 16, 24, and 48 weeks. The 16-week data on which the IDX899 dose will be selected is expected in Apr 2011. (The expected completion date, according to clinicaltrails.gov, is Dec 2015, but this must include safety monitoring well beyond 48 weeks.)

Insofar as the trial described above is testing IDX899 and Isentress in the same cocktail, the drug-drug-interaction study conducted by GSK last spring (#msg-48913630) must have had adequate results. (clinicaltrals.gov shows that this trial is “not yet open,” but this is presumably an error.)

As previously noted (#msg-54847385 ), a phase-2b trial in the first-line setting, testing IDX899+Truvada vs Sustiva+Truvada, is expected to start in early 2011.

A phase-2b trial testing IDX899 with GSK’s own integrase inhibitor, S/GSK1349572 may or may not be in the works; IDIX has furnished no information on such a study recently, which suggests that the idea is on the back burner.