Foundations of ART Management in Heavily Treatment–Experienced Patients

Those healthcare professionals who have been treating patients with HIV for only a few years may not have had direct experience with multidrug-resistant virus. We should consider how multidrug-resistant HIV occurs.²

In the early days of ART, it was routine to use monotherapy regimens or sequentially add a second drug to compose a dual-therapy regimen. Unfortunately, it was only later that we learned that this was the recipe to sequentially select for increasingly resistant virus.

One of the most important factors that defines whether someone will have highly treatment–resistant virus is whether they ever received an unboosted protease inhibitor (PI)—such as nelfinavir or indinavir—because these people were at risk for developing PI-resistant virus. Those who started with a boosted PI as their first regimen rarely developed protease resistance.

How often do we see these heavily treatment–experienced patients? In reality, this is a relatively rare event. These are data from the Centers for AIDS Research Network of Integrated Clinical Systems, which includes more than 26,000 treatment-experienced people in care in multiple clinics.³ Among this cohort, the investigators looked at the number who had limited treatment options, including ≤2 available classes or ≤2 active drugs. In the Years 2000-2007, the prevalence was in the range of 5% to 7%, but by 2008, the percentage of people in care with multidrug-resistant virus dropped to 1% to 2%.

Although people with multidrug-resistant HIV are relatively uncommon in current practice, they are an extremely important group because the stakes are very high to do everything possible to get their virus under control and prevent them from selecting for additional resistance.