Researchers in Barcelona, Spain, reported results from a pilot study where volunteers who were taking ART were screened and then recruited. Once in the study their regimens were changed to the following combination of just two drugs:

  • etravirine (Intelence) 200 mg every 12 hours and raltegravir (Isentress) 400 mg every 12 hours

Prior to entering the study, all participants had their viral loads below the 50-copy/ml mark for at least six months.

According to the researchers, in general, participants "were [in their mid-50s] ... and had a long history of HIV infection and extensive treatment experience and changed to dual therapy mostly for tolerance and toxicity problems [with their prior treatments]."


Researchers reported results from 25 participants (52% male, 48% women) after at least 48 weeks of observation. At the end of 48 weeks, 84% (21 out of 25 participants) continued to have viral loads less than 50 copies/ml.

At the start of the study, CD4+ counts were about 400 cells and at the 48th week they increased to about 500 cells/ml.

All 21 participants who reached week 48 of the study with a low viral load (less than 50 copies/ml) chose to continue with the study regimen, in some cases for up to a total of 194 weeks without any problems.

There were small but favourable improvements in levels of HDL-cholesterol, glucose (sugar) and triglycerides in the blood of participants at week 48.

Adverse Events

The researchers stated that two participants quit the study after eight weeks because of "gastrointestinal intolerance."

Among participants who continued in the study there were no reports of rash.

One death was reported, due to overwhelming bacterial infection. This was not due to the study drugs.


Technicians assessed blood samples for levels of etravirine and raltegravir and found them to be "adequate," including cases where treatment failure occurred.


These results, while interesting and hopeful, are not definitive. However, the study can serve as a guide when designing a more robust clinical trial to explore the effects of dual therapy with etravirine and raltegravir.


Monteiro P, Perez I, Laguno M, et al. Dual therapy with etravirine plus raltegravir for virologically suppressed HIV-infected patients: a pilot study. Journal of Antimicrobial Chemotherapy. 2014 Mar;69(3):742-8.