HIV-1 infection kinetics, drug resistance, and long-term safety of pre-exposure prophylaxis with emtricitabine plus tenofovir alafenamide (DISCOVER): week 144 open-label extension of a randomised, controlled, phase 3 trial.

BACKGROUND

Data characterising the long-term use and safety of emtricitabine plus tenofovir disoproxil fumarate as daily oral pre-exposure prophylaxis (PrEP) are scarce and there are uncertainties regarding the value of routine HIV-1 RNA testing during oral PrEP follow-up.

METHODS

The DISCOVER trial was a randomised, controlled, phase 3 trial in which cisgender men and transgender women aged 18 years and older with a high likelihood of acquiring HIV were recruited from 94 clinics in Europe and North America and randomly assigned to receive either emtricitabine plus tenofovir disoproxil fumarate (200/25 mg) tablets daily, with matched placebo tablets, or emtricitabine plus tenofovir alafenamide (200/300 mg) tablets daily, with matched placebo tablets, for at least 96 weeks. After completion of the trial, participants were offered enrolment in this 48-week open-label extension study of emtricitabine plus tenofovir alafenamide. In participants diagnosed with HIV during the randomised and open-label phases of the study, we characterised HIV-1 test results and measured HIV-1 RNA viral load retrospectively when available. Adherence based on tenofovir diphosphate concentrations in dried blood spots and genotypic resistance were assessed in participants diagnosed with HIV. Safety assessments included adverse events, laboratory parameters, and, in a subset of participants, bone mineral density. HIV-1 incidence in participants initially randomly assigned to receive emtricitabine plus tenofovir alafenamide was estimated using a Poisson distribution. Changes from baseline in safety endpoints were described in participants assigned to received emtricitabine plus tenofovir alafenamide and in those who switched from emtricitabine plus tenofovir disoproxil fumarate during the open-label phase. This trial is registered with ClinicalTrials.gov, NCT02842086, and is ongoing.

FINDINGS

Between Sept 13, 2016, and June 30, 2017, 5399 participants were enrolled and randomly assigned in DISCOVER. 2699 were assigned to receive emtricitabine plus tenofovir disoproxil fumarate and 2700 were assigned to receive emtricitabine plus tenofovir alafenamide, of whom 2693 and 2694, respectively, received at least one dose of study drug. 2115 (79%) assigned to emtricitabine plus tenofovir disoproxil fumarate switched to emtricitabine plus tenofovir alafenamide in the open-label phase, and 2070 (77%) continued with emtricitabine plus tenofovir alafenamide in the open-label phase. As of data cutoff (Dec 10, 2020), after 15 817 person-years of follow-up, 27 new HIV-1 diagnoses were observed across the total study period, with three occurring during the open-label phase. In participants who were initially assigned to emtricitabine plus tenofovir alafenamide, the incidence was 0·13 per 100 person-years (95% CI 0·061-0·23; ten of 2670). Stored plasma samples were available for 23 of 27 participants, including 22 with incident infection. In four (17%) of 23 participants, retrospective testing detected HIV-1 RNA before serological HIV-1 test positivity; one was a suspected baseline infection. Of the three incident cases, all three were non-adherent to PrEP and none developed drug resistance. Among participants taking emtricitabine plus tenofovir alafenamide for up to 144 weeks, markers of glomerular filtration and proximal renal tubule dysfunction (β2-microglobulin to creatinine ratio and retinol-binding protein to creatinine ratio) improved or remained stable at 144 weeks compared with baseline, bone mineral density in hip and lumbar spine increased or remained stable from baseline to week 144 (n=191), cholesterol and glucose concentrations remained stable, and median bodyweight increased by less than 1 kg per year. In participants who switched from emtricitabine plus tenofovir disoproxil fumarate during the open-label phase (2115 [79%] of 2693), markers of glomerular filtration and proximal renal tubule dysfunction improved or remained stable, bone mineral density increased, cholesterol concentrations increased, glucose concentrations were similar, and median bodyweight increased more compared with those who remained on emtricitabine and tenofovir alafenamide.

INTERPRETATION

Routine HIV-1 RNA testing for follow-up of individuals on daily oral PrEP provides modest additional clinical benefit. Long-term use of emtricitabine and tenofovir alafenamide as daily oral PrEP is safe and well tolerated and can be an especially appropriate choice for people with bone or renal morbidities.

FUNDING

Gilead Sciences.

Informations de copyright

Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.

Déclaration de conflit d'intérêts

Declaration of interests DAW has received grants, consulting fees, and speaker honoraria from Gilead Sciences; grants from Merck; consulting fees and speaker honoraria from ViiV Healthcare; and consulting fees and speaker honoraria from Janssen Pharmaceuticals. CDS has received funding, grants, consulting fees, and non-financial support from Gilead Sciences; grants and speaker honoraria from AbbVie; grants and personal fees from Janssen-Cilag; grants and personal fees from MSD, ViiV Healthcare, BioNtech, and Eli Lilly; grants from Cepheid; grants, personal fees, and non-financial support from B Braun Melsungen; consulting fees from AstraZeneca; personal fees, non-financial support, and other support outside the submitted work from Apeiron Biologics; and personal fees from GSK, Formycon, Moderna, Molecular Partners, Novartis, Roche, Sobi, and Pfizer. JF, PJR, and RMG have received research funding from Gilead Sciences. CBH has received research grant support from Gilead Sciences. SD-L has received research grant support (paid to their institution) from Gilead Sciences and Merck. J-MM has received grants (paid to their institution) from Gilead Sciences and Merck; consulting fees from Gilead Sciences, Merck, and ViiV Healthcare; and payments for participation on an advisory board from AELIX Therapeutics. AM has received research funding (paid to their institution) from Gilead Sciences, ViiV Healthcare, Merck, GSK, AbbVie, and TaiMed Biologics; speaker honoraria from Gilead Sciences, ViiV Healthcare, and EMD Serono; and payments for participation on an advisory board from Gilead Sciences and ViiV Healthcare. CB has received funding and speaker honoraria from Gilead Sciences; speaker honoraria from ViiV Healthcare; and support for attending principal investigator meetings from Gilead Sciences, ViiV Healthcare, GSK, PPD (Thermo Fisher Scientific), Merck, Viking Therapeutics, Syneos Health, Novo Nordisk, AbbVie, Regeneron Pharmaceuticals, Janssen, and Shionogi. MR has received funding and speaker and consulting fees from Gilead Sciences, speaker and consulting fees from ViiV Healthcare, consulting fees from MSD and Abbott, and speaker honoraria from AbbVie and Janssen. AC has received advisory boards fees from Gilead Sciences, ViiV Healthcare, MSD, and Theratechnologies; funding for clinical trials (paid to their institution) from Gilead Sciences, MSD, GSK, ViiV Healthcare, and Pfizer; speaker fees from MSD; and support for congress attendance from Gilead Sciences and ViiV Healthcare. GC has received research funding (paid to their institution) from Gilead Sciences for conducting research discussed in this manuscript. CM has received funding and speaker fees from Gilead Sciences and grants and speaker fees from ViiV Healthcare and Theratechnologies. CC, SC, JCH, YS, MD, AK, and JMB are shareholders and employees of Gilead Sciences. KMo has received funding from Gilead Sciences; speaker fees and advisory board fees from Gilead Sciences, ViiV Healthcare, Janssen Therapeutics, Theratechnologies, and Epividian; and funding for clinical trials (paid to their institution) from Gilead Sciences, ViiV Healthcare, and Janssen Therapeutics. KMa has received research funding from Gilead Sciences, and unrestricted grants and advisory board fees from Gilead Sciences and Merck.