Efficacy, Safety & Tolerability of Switching EFV/TDF/FTC to BIC/FTC/TAF in Virologically Suppressed Adults With HIV-1

Therapeutic dosage of the tenofovir disoproxil fumarate (TDF) component of ATRIPLA® requires plasma concentrations of the drug that are associated with nephrotoxicity and decreased bone mineral density. Tenofovir alafenamide fumarate (TAF) has a unique metabolism that results in higher intracellular levels of the active phosphorylated moiety tenofovir-diphosphate. Compared with TDF, the therapeutic dosage of TAF reduces tenofovir plasma concentrations by over 90%. This reduction in plasma concentration results in decreased renal and bone risks. TAF has the potential to improve on the efficacy and safety profile of TDF. Efavirenz, another component of ATRIPLA® is widely associated with neuropsychiatric side-effects, including sleep disturbances, depression, and anxiety. Switching from Efavirenz to an integrase inhibitor is associated with improvements in mood. Bictegravir (BIC) is a novel, once daily integrase inhibitor. It has been shown to have potent antiviral activity, a favorable pharmacokinetic profile, good tolerability and an improved resistance profile when compared to previous integrase inhibitors. In a phase 2 trial investigating previously untreated people with HIV, bictegravir plus emtricitabine and tenofovir alafenamide (BIKTARVY®) vs dolutegravir, plus emtricitabine and tenofovir alafenamide both showed high efficacy up to 24 weeks and both regimens were well tolerated. Additionally, switching HAART experienced patients to BIKTARVY® has been shown to be non-inferior to continuation of regimens containing Atazanavir or Darunavir, when they were given with either lamivudine/abacavir or FTC/TDF. The Investigators plan to evaluate in a real world setting the efficacy, safety and tolerability of switching from the older, established single tablet regimen of ATRIPLA® (EFV/FTC/TDF) to a new single tablet regimen of BIKTARVY® (BIC/FTC/TAF). Within the limitations of a real-world study, Investigators have attempted to replicate the protocol of Gilead Science's Phase 3 study evaluating a switch to BIC/FTC/TAF from dolutegravir plus either FTC/TAF or FTC/TDF14. This will have the potential benefit of comparing different regimen switches as well as potentially adding robustness to the body of data regarding BIC/FTC/TAF.