Their argument is supported by fi ndings of a
subgroup analysis, in which a regimen containing
one active background drug is less likely to achieve
virological suppression than one with two active
background drugs. In this study, among patients with
one active background drug, 78% in the elvitegravir
group and 68% in the raltegravir group achieved viral
suppression; among those with two active background
drugs the proportions were 59% and 55%, respectively.
Again, patients with two active background drugs
had signifi cantly higher voluntary discontinuation
rates (p=0·015), suggesting decreasing adherence as
remaining treatment options increase. This paradoxical
virological response rate is, however, in stark contrast
to previous observations in similar trials with raltegravir
(BENCHMRK),12 etravirine (DUET),13 and maraviroc
(MOTIVATE).