February 4, 2001
The final presentation was given by J. Durant and reported the week 12 results of the PharmAdapt trial. This study was an effort by Swiss investigators to examine the role of therapeutic drug monitoring on the outcome of salvage therapy. The study was ambitious, involving 256 subjects. All subjects had genotypic adjustments made in their regimen. At week four, half of the subjects had pK measures obtained and provided to the physician by week eight when a further adjustment in the regimen or dosing could be made. No difference in plasma RNA suppression at week twelve was observed when the control and pK assisted groups were compared. It was my impression that the study was doomed to fail for a number of reasons. The patients were highly treatment-experienced and appeared to be managed by knowledgeable HIV treaters. Many of the study subjects in both arms were already on ritonavir-boosted PI therapy and only 19% of the pK group had a change made at the week eight visit. Those features of the study would make it difficult to demonstrate any benefit of pK data. The bottom line is that the pharmacology data presented today underscores the complexity of truly understanding the pharmacology of HIV therapeutics and did little to resolve the debate about the merit of therapeutic drug monitoring.