Triple-Class Failure in HIV-Infected Patients

Many patients treated before the availability of potent combination antiretroviral therapy (ART) developed resistance to multiple agents because of sequential monotherapy or dual therapy. How commonly do HIV-infected patients who initiate ART with ≥3 drugs develop extensive triple-class virologic failure (TCVF), defined as failure of multiple nucleoside reverse-transcriptase inhibitors (RTIs), of a nonnucleoside RTI, and of a ritonavir-boosted protease inhibitor (PI)? To find out, investigators studied an observational cohort of 7916 patients who initiated ART with ≥3 agents. The patients were treated at 10 large centers in the U.K.

During 27,441 person-years of observation, extensive TCVF developed in 167 patients. Ninety percent of patient…