Clinical Benefit of Continuing a Failing ART Regimen in AIDS Patients

Studies of treatment interruption in salvage therapy have yielded disappointing results (ACC Oct 1 2003). However, the benefits of continuing a failing antiretroviral regimen in a salvage setting are also questionable. Now, investigators in France have compared the clinical outcomes of stopping antiretroviral therapy (ART), continuing a failing regimen, and maintaining suppressive ART in patients with AIDS.

The 12,765 study participants received ART between 2000 and 2005 and had CD4 counts <200 cells/mm³ while receiving such treatment. Of these patients, 18% had at least one treatment interruption lasting ≥3 months, 69% had at least one period of virologic failure (≥2 consecutive viral-load measurements ≥500 copies/mL), and 51% had at least one period of virologic suppression (≥2 consecutive viral-load measurements <500 copies/mL). Investigators compared the incidence of AIDS-defining events during treatment interruption with the incidence during virologic failure and the incidence during virologic suppression. Thirty-four percent of patients were included in more than one of these exposure groups (for example, a single patient could have contributed data during both a treatment interruption and a period of virologic suppression). Results were stratified by the patient’s CD4 count (<50 vs. 50–200 cells/mm³) at the time of entry into a given exposure group.

The rate of new AIDS-defining events (per 100 patient-years) was 18.5 during treatment interruptions, 14.5 during periods of virologic failure, and 4.9 during periods of virologic suppression. Similar differences were noted in both CD4-cell–count strata and for all types of events (viral, fungal, protozoal, bacterial, and other). In a multivariate analysis, risk for a new AIDS-defining event was 22% lower during virologic failure — and 62% lower during virologic suppression — than risk during treatment interruption.