Your summary of 908's CONTEXT trial is correct-- the primary endpoint was to test non-inferiority of boosted 908 vs Kaletra in experience patients, looking at a viral load area under the curve minus baseline analysis (AAUCMB). The 48 week analysis has been released in brief and failed to show non-inferiority at the 97.5% confidence intervals. The same analysis also failed to prove inferiority of 908, and did not prove superiority of Kaletra.
The proportions of patients who achieved undetectable viral loads (and the CD4 cell change) were similar between bid-dosed boosted 908 and Kaletra.
I find the first results a statistical wash, meaning that while we cannot say that the drugs are the same, we cannot say that there are differences either. As a result, I depend more on the secondary endpoints for guidance and here the results are more familiar and show similar performances. Are there any differences? perhaps; but recognize that this study randomized patients to receive the drug regimens and in the real world we should be able to carefully pick the regimen based on resistance testing and clinical judgement.
I don't think that the study raises that many questions, since (see below) the selection of salvage therapies depend on many factors.
It's my guess that 908- either boosted or unboosted will play an important role in increasing therapeutic options for patients and clinicians alike. Having another option to treat experienced patients is essential and amprenavir's resistance profile is very encouraging among heavily pre-treated patients. BY
