"That Dog Won't Hunt" Dept.: Once A Day Isentress®

This is actually scant news -- if it is news at all. [Earlier background on Isentress^® revenue-model here.]

From Whitehouse Station this morning, then:

. . . .This Phase III study evaluated the safety and efficacy of an investigational once-daily dose of raltegravir (800 mg once daily) versus the approved twice-daily dose (400 mg twice daily), each given in combination with a once-daily fixed-dose combination of emtricitabine and tenofovir disoproxil fumarate, in adult treatment-naïve HIV-1-infected patients. In this study, 775 patients were randomized, and 770 patients received study drug and are included in the current analyses. After 48 weeks in the study, 83.2 percent (n=318/382) of patients receiving the regimen including ISENTRESS once daily achieved undetectable viral levels (HIV-RNA < 50 copies/mL), compared to 88.9 percent (n=343/386) of patients receiving the regimen including ISENTRESS twice daily. The treatment difference between the 800 mg once daily group and 400 mg twice daily group was -5.7 percent, with an associated 95 percent confidence interval (CI) of (-10.7 percent, -0.83 percent). The difference did not meet the pre-defined statistical criteria for non-inferiority.

The overall treatment difference observed between the once-daily and twice-daily groups was primarily due to results in patients with high viral load. Among patients with more than 100,000 copies/mL of HIV-RNA, 74.3 percent (n=113/152) of those in the once-daily group achieved viral suppression compared to 84.2 percent (n=128/152) of those in the twice-daily group. . . .

In some ways, as perverse as it sounds, this actually means Merck will procure a continuing "double-dose" of Isentress^® -- a good thing, from the perspective of its gross revenues line. There is the chance, though, that Gilead's candidate becomes a clear winner, here -- and takes the bulk of the revenue in the next few years. But that is rather a long-shot -- as it is hard to see a path for reimbursement of what would have to be a nearly universal prophylactic. Stay tuned.