Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) is a single pill regimen that was approved by the FDA in February 2018 for treatment of HIV. The marketed name of the drug is Biktarvy. In two phase 3 comparative clinical trials, including one with ABC/3TC/DTG, it was found to be non-inferior to dolutegravir-containing regimens in terms of virologic outcomes. B/F/TAF was also well tolerated, with few discontinuations for adverse events. As a result, B/F/TAF is an ideal non-abacavir containing regimen to assess the effect of removing ABC on coronary flow reserve.
Positron emission tomography (PET) imaging allows precise and reproducible quantification of myocardial blood flow, thereby providing a direct assessment of coronary vascular health. Coronary flow reserve (CFR, calculated as the ratio of peak hyperemic myocardial blood flow over that at rest) is emerging as a powerful quantitative prognostic imaging marker of clinical cardiovascular risk. CFR provides a robust and reproducible clinical measure of the integrated hemodynamic effects of epicardial coronary artery disease (CAD), diffuse atherosclerosis, vessel remodeling, and microvascular dysfunction resulting from endothelial cell dysfunction on myocardial tissue perfusion across the entire coronary circulation. These processes have direct relevance to the underlying vascular pathobiology in patients with HIV infection. Consequently, quantitative CFR provides a unique opportunity to examine the potential impact of novel therapies on the biology of the disease and its association with cardiovascular outcomes. By testing the fundamental concept of whether novel ART therapies in HIV can lead to improved coronary blood flow and myocardial tissue perfusion, TAF-CFR would provide important mechanistic insights of the capabilities of TAF therapy to improve key determinants of clinical risk. This is an open label, multicenter, uncontrolled, single arm pilot study. Patients with stable HIV currently treated with abacavir/lamivudine/dolutegravir STR regimens will be eligible for the B/F/TAF-CFR study. PET scans will be performed after enrollment while on the abacavir/lamivudine/dolutegravir STR regimen and at 24 weeks after the switch to B/F/TAF regimen. Patients will be encouraged to remain on stable medical therapy throughout the enrollment period.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
25
Open-label, multicenter, single-arm study to Evaluate the Safety and Efficacy of Switching from Regimens Consisting of Abacavir/Lamivudine/Dolutegravir (ABC/3TC/DTG) to the Bictegravir/ Emtricitabine/Tenofovir Alafenamide (B/F/TAF) Fixed-Dose Combination (FDC) in Virologically-Suppressed HIV-Infected Adult Subjects
Tufts Medical Center
Boston, Massachusetts, United States
Brigham and Women's Hospital
Boston, Massachusetts, United States
Boston Medical Center
Boston, Massachusetts, United States
Change in Global CFR
Change in global coronary flow reserve, as measured by PET imaging at baseline and 24 weeks after initiation of B/F/TAF therapy. Coronary flow reserve (CFR), the ratio of peak vasodilator stress to rest myocardial blood flow (MBF), represents the maximal ability to augment coronary flow and myocardial perfusion. Absolute MBF was computed from the rest and stress myocardial perfusion PET images using commercially available software (Corridor4DM; Ann Arbor, Michigan) and a two-compartment tracer kinetic model. Impaired MBFR is defined as a ratio of \<2.0, which is associated with increased cardiovascular risk.
Time frame: baseline and week 24
Change in Peak Stress Global MBF
Change (from baseline) in peak-stress global myocardial blood flow (in mL/min/g) at 24 weeks after initiation of B/F/TAF. Absolute MBF was computed from the rest and stress myocardial perfusion PET images using commercially available software (Corridor4DM; Ann Arbor, Michigan) and a two-compartment tracer kinetic model. Impaired stress MBF is defined as \<1.8 mL/min/g and is associated with increased cardiovascular risk.
Time frame: baseline and 24 weeks
Change in Serum Biomarkers of Inflammation (Hs-CRP (in mg/L))
Change in serum biomarkers of inflammation (hs-CRP (in mg/L)) at 24 weeks after initiation of B/F/TAF. Serum biomarkers of inflammation (high sensitivity C-reactive protein) were measured. hs-CRP \> 1 mg/L are considered abnormal and associated with increased cardiovascular risk.
Time frame: Baseline and 24 weeks
Change in Myocyte Injury and Strain (hs Troponin (in ng/L))
Change in Myocyte Injury and Strain (hs Troponin (in ng/L)) at 24 weeks after initiation of B/F/TAF. Serum biomarkers of myocardial injury/strain (high sensitivity troponin) were measured. hs-troponin \>14 ng/L are considered abnormal and associated with increased cardiovascular risk.
Time frame: Baseline and 24 weeks
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Change in Myocyte Injury and Strain (NT-proBNP (in pg/mL))
Change in Myocyte Injury and Strain (NT-proBNP (in pg/mL)) at 24 weeks after initiation of B/F/TAF. Serum biomarkers of myocardial injury/strain (NT-pro-BNP) were measured. NT-proBNP \> 100 pg/mL are considered abnormal and associated with increased cardiovascular risk.
Time frame: Baseline and 24 weeks