A presentation at the 2015 International AIDS Society conference in Vancouver reported 24-week results comparing a maintenance regimen of rilpivirine (Edurant) + boosted darunavir (Prezista/ritonavir) to a three-drug regimen of a boosted protease inhibitor and two NRTIs. This could offer some people a new treatment option should they experience significant adverse effects or resistance while on NRTIs.
The PROBE study enrolled 60 people who had controlled HIV for more than six months. Everyone was on a boosted protease inhibitor regimen with either Truvada (emtricitabine/tenofovir) or Epzicom (abacavir/lamivudine). Half of them continued on their regimens while the other half switched to the maintenance regimen.
Four out of five participants were men, average age was 48, and 1 out of 5 had had a previous AIDS diagnosis. No one had HIV that was resistant to rilpivirine and no one had current hepatitis B infection. The great majority (83%) had been on regimens with either boosted atazanavir (Reyataz) or boosted darunavir. The median time on HIV meds was 6.2 years, and the median number of regimens that had been used per person was 3. Average CD4 count was 623 and everyone had undetectable viral loads.
At 24 weeks, after being randomized to switch or stay on their previous regimens, no one had to stop therapy for any reason. Everyone who switched to the maintenance regimen continued to have viral load <50 copies, compared to 86.7% in the other group. Those on the maintenance regimen had a slightly higher increase in CD4s (+24 vs. -13) but fewer CD8 cells (-4 vs. +17). As for fasting triglycerides, the maintenance regimen had less of an increase (+10mg/dl vs. +23mg), and the regimen had larger increases in both total (+14mg/dl vs. -0.7mg) and HDL ("good") cholesterol (+0.6mg/dl vs. -4.2mg).
F Maggiolo, et al. Switch from PI/rtv + 2 nucleos(t)ides to RPV+DRV/rtv maintains HIV suppression and is well tolerated. IAS 2015, Vancouver, Canada. July 19â€“22, 2015.