Triple-Class Failure Rates Plateau

In the early years of successful combination antiretroviral therapy (ART), patients who experienced treatment failure on both protease inhibitor (PI)- and nonnucleoside reverse transcriptase inhibitor (NNRTI)-based combinations were mostly those who had started ART with one drug, then added a second, and subsequently a third, leading to the sequential accumulation of classwide resistance mutations. How common is triple-class virologic failure now that patients start treatment with combination ART?

Researchers examined a huge European database to identify individuals who began combination ART after January 1998 and developed treatment failure after exposure to a PI, an NNRTI, and at least two nucleosides. Treatment failure was defined as a vi…