Dataset Information

Two-dose emtricitabine/tenofovir alafenamide plus bictegravir prophylaxis protects macaques against SHIV infection.

ABSTRACT:

Objectives

Current prophylaxis options for people at risk for HIV infection include two US FDA-approved daily pre-exposure prophylaxis (PrEP) regimens and guidelines for a 2-1-1 event-driven course specifically for men who have sex with men. Despite this, PrEP use rates remain suboptimal, and additional PrEP options may help to improve uptake among diverse populations. Here, we evaluated protective efficacy of two-dose PrEP and two-dose postexposure prophylaxis (PEP) schedules with emtricitabine (FTC)/tenofovir alafenamide (TAF) with or without bictegravir (BIC) in an SHIV macaque model.

Methods

Macaques received one oral dose of 200?mg emtricitabine, 25?mg tenofovir alafenamide and 25-100?mg of bictegravir to establish pharmacokinetic profiles of each drug either in the plasma or the peripheral blood mononuclear cells. Protective efficacy of multiple two-dose PrEP and PEP schedules with FTC/TAF with or without bictegravir was then assessed in two repeat low-dose rectal SHIV challenge studies.

Results

The data revealed over 95% per-exposure risk reduction with FTC/TAF PrEP initiated 2?h before the exposure, but a loss of significant protection with treatment initiation postexposure. In contrast, FTC/TAF plus BIC offered complete protection as PrEP and greater than 80% per-exposure risk reduction with treatment initiation up to 24?h postexposure.

Conclusions

Together, these results demonstrate that two-dose schedules can protect macaques against SHIV acquisition and highlight the protective advantage of adding the integrase inhibitor bictegravir to the reverse transcriptase inhibitors emtricitabine and tenofovir alafenamide as part of event-driven prophylaxis.

SUBMITTER: Bekerman E

PROVIDER: S-EPMC7879143 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

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Publications

Two-dose emtricitabine/tenofovir alafenamide plus bictegravir prophylaxis protects macaques against SHIV infection.

Bekerman Elena E Cox Stephanie S Babusis Darius D Campigotto Federico F Das Moupali M Barouch Dan H DH Cihlar Tomas T Callebaut Christian C

The Journal of antimicrobial chemotherapy 20210201 3

<h4>Objectives</h4>Current prophylaxis options for people at risk for HIV infection include two US FDA-approved daily pre-exposure prophylaxis (PrEP) regimens and guidelines for a 2-1-1 event-driven course specifically for men who have sex with men. Despite this, PrEP use rates remain suboptimal, and additional PrEP options may help to improve uptake among diverse populations. Here, we evaluated protective efficacy of two-dose PrEP and two-dose postexposure prophylaxis (PEP) schedules with emtri ...[more]

PMID: 33202006

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Project description:BackgroundIn the absence of an effective vaccine, HIV continues to spread globally, emphasizing the need for novel strategies to limit its transmission. Pre-exposure prophylaxis (PrEP) with antiretroviral drugs could prove to be an effective intervention strategy if highly efficacious and cost-effective PrEP modalities are identified. We evaluated daily and intermittent PrEP regimens of increasing antiviral activity in a macaque model that closely resembles human transmission.Methods and findingsWe used a repeat-exposure macaque model with 14 weekly rectal virus challenges. Three drug treatments were given once daily, each to a different group of six rhesus macaques. Group 1 was treated subcutaneously with a human-equivalent dose of emtricitabine (FTC), group 2 received orally the human-equivalent dosing of both FTC and tenofovir-disoproxil fumarate (TDF), and group 3 received subcutaneously a similar dosing of FTC and a higher dose of tenofovir. A fourth group of six rhesus macaques (group 4) received intermittently a PrEP regimen similar to group 3 only 2 h before and 24 h after each weekly virus challenge. Results were compared to 18 control macaques that did not receive any drug treatment. The risk of infection in macaques treated in groups 1 and 2 was 3.8- and 7.8-fold lower than in untreated macaques (p = 0.02 and p = 0.008, respectively). All six macaques in group 3 were protected. Breakthrough infections had blunted acute viremias; drug resistance was seen in two of six animals. All six animals in group 4 that received intermittent PrEP were protected.ConclusionsThis model suggests that single drugs for daily PrEP can be protective but a combination of antiretroviral drugs may be required to increase the level of protection. Short but potent intermittent PrEP can provide protection comparable to that of daily PrEP in this SHIV/macaque model. These findings support PrEP trials for HIV prevention in humans and identify promising PrEP modalities.

Project description:BackgroundBictegravir (B)/emtricitabine (F)/tenofovir alafenamide (TAF) is guideline-recommended treatment for human immunodeficiency virus type 1 (HIV-1). We evaluated whether people receiving dolutegravir (DTG) plus F/TAF or F/TDF (tenofovir disoproxil fumarate) with viral suppression can switch to B/F/TAF without compromising safety or efficacy, regardless of preexisting nucleoside reverse transcriptase inhibitor (NRTI) resistance.MethodsIn this multicenter, randomized, double-blinded, active-controlled, noninferiority trial, we enrolled adults who were virologically suppressed for ≥6 months before screening (with documented/suspected NRTI resistance) or ≥3 months before screening (with no documented/suspected NRTI resistance) on DTG plus either F/TDF or F/TAF. We randomly assigned (1:1) participants to switch to B/F/TAF or DTG + F/TAF once daily for 48 weeks, each with matching placebo. The primary endpoint was proportion of participants with plasma HIV-1 RNA ≥50 copies/mL at week 48 (snapshot algorithm); the prespecified noninferiority margin was 4%.ResultsFive hundred sixty-seven adults were randomized; 565 were treated (284 B/F/TAF, 281 DTG + F/TAF). At week 48, B/F/TAF was noninferior to DTG + F/TAF, as 0.4% (1/284) vs 1.1% (3/281) had HIV-1 RNA ≥50 copies/mL (difference, -0.7% [95.001% confidence interval {CI}, -2.8% to 1.0%]). There were no significant differences in efficacy among participants with suspected or confirmed prior NRTI resistance (n = 138). No participant had treatment-emergent drug resistance. Median weight change from baseline at week 48 was +1.3 kg (B/F/TAF) vs +1.1 kg (DTG + F/TAF) (P = .46). Weight change differed by baseline NRTIs (+2.2 kg [F/TDF] and +0.6 kg [F/TAF], P < .001), with no differences between B/F/TAF and DTG + F/TAF.ConclusionsThe single-tablet regimen B/F/TAF is a safe, effective option for people virologically suppressed on DTG plus either F/TDF or F/TAF, including in individuals with preexisting resistance to NRTIs.Clinical trials registrationNCT03110380.

Project description:BackgroundBictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) is a single-tablet regimen recommended for HIV-1 treatment. The safety and efficacy of B/F/TAF as initial therapy was established in two Phase 3 studies: 1489 (vs dolutegravir [DTG]/abacavir/lamivudine) and 1490 (vs DTG + F/TAF). After 144 weeks of randomized follow-up, an open-label extension evaluated B/F/TAF to 240 weeks.MethodsOf 634 participants randomized to B/F/TAF, 519 completed the double-blinded treatment, and 506/634 (80%) chose the 96-week open-label B/F/TAF extension, which was completed by 444/506 (88%) participants. Efficacy was based on the secondary outcome of the proportion of participants with HIV-1 RNA <50 copies/mL at Week 240 by missing = excluded and missing = failure methods. All 634 participants who were randomized to B/F/TAF and received at least one dose of B/F/TAF were included in efficacy and safety analyses. (Study 1489: ClinicalTrials.govNCT02607930; EudraCT 2015-004024-54. Study 1490: ClinicalTrials.govNCT02607956; EudraCT 2015-003988-10).FindingsOf those with available virologic data, 98.6% (95% CI [97.0%-99.5%], 426/432) maintained HIV-1 RNA <50 copies/mL at Week 240 (missing = excluded); when missing virologic data were considered as failure, 67.2% (95% CI [63.4%-70.8%], 426/634) maintained HIV-1 RNA <50 copies/mL. Mean (SD) change in CD4+ count from baseline was +338 (236.2) cells/μL. No treatment-emergent resistance to B/F/TAF was detected. Adverse events led to drug discontinuation in 1.6% (n = 10/634) of participants (n = 5 with events considered drug-related). No discontinuations were due to renal adverse events. Median (IQR) total cholesterol increased 21 (1,42) mg/dL from baseline; the change in total cholesterol:HDL was 0.1 (-0.5,0.6). Median (IQR) weight change from baseline was +6.1 kg (2.0, 11.7) at Week 240. In Study 1489, hip and spine bone mineral density mean percent changes from baseline were ≤0.6%.InterpretationThrough 5 years of follow-up, B/F/TAF maintained high rates of virologic suppression with no treatment-emergent resistance and rare drug discontinuations due to adverse events. These results demonstrate the durability and safety of B/F/TAF in people with HIV.FundingGilead Sciences.

Dataset Information

Two-dose emtricitabine/tenofovir alafenamide plus bictegravir prophylaxis protects macaques against SHIV infection.

Objectives

Methods

Results

Conclusions

Publications

Two-dose emtricitabine/tenofovir alafenamide plus bictegravir prophylaxis protects macaques against SHIV infection.

Similar Datasets

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