Research has begun to explore combining the protease inhibitor Prezista (darunavir) with the experimental boosting drug called cobicistat into one pill. Prezista is currently a preferred drug for people going on HIV treatment for the first time.
Prezista is now taken with a separate small dose of Norvir (ritonavir) to maintain its blood level. Combining it with cobicistat would cut down on the number of pills a person would have to take each day. There may also be another benefit as cobicistat has, so far in clinical studies, shown to cause less problems with gastrointestinal distress and lipid elevations, though it does cause elevations in certain kidney enzymes when a person starts taking it.
Further development of Prezista + cobicistat will also continue towards its own full-regimen pill. If the drug manufacturers sign their development agreements, Prezista + cobicistat will be combined with Emtriva (emtricitabine) and an experimental pro-drug version of tenofovir called GS 7340.
Cobicistat is also currently being studied as part of the new “quad” pill, which is made up of Viread (tenofovir), Emtriva (emtricitabine) and the experimental integrase inhibitor elvitegravir. If successful in its clinical study, the “quad” will be the third complete single-tablet regimen, behind Atripla and the recently approved Complera.
With luck, perhaps sometime in 2013, we may see as many as four combination pills available for people to take as a complete regimen.