A Trial of a Single-tablet Regimen of Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir Disoproxil Fumarate for the Initial Treatment of Human Immunodeficiency Virus Type 2 Infection in a Resource-limited Setting: 48-Week Results From Senegal, West Africa

Abstract

Background: There is an urgent need for safe and effective antiretroviral therapy (ART) for human immunodeficiency virus type 2 (HIV-2) infection. We undertook the first clinical trial of a single-tablet regimen containing elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (E/C/F/TDF) to assess its effectiveness in HIV-2-infected individuals in Senegal, West Africa.

Methods: HIV-2-infected, ART-naive adults with World Health Organization stage 3-4 disease or CD4 count <750 cells/μL were eligible for this 48-week, open-label trial. We analyzed HIV-2 viral loads (VL), CD4 counts, clinical and adverse events, mortality, and loss to follow-up.

Results: We enrolled 30 subjects who initiated E/C/F/TDF. Twenty-nine subjects completed 48 weeks of follow-up. The majority were female (80%). There were no deaths, no new AIDS-associated clinical events, and 1 loss to follow-up. The median baseline CD4 count was 408 (range, 34-747) cells/μL, which increased by a median 161 (range, 27-547) cells/μL at week 48. Twenty-five subjects had baseline HIV-2 VL of <50 copies/mL of plasma. In those with detectable HIV-2 VL, the median was 41 (range, 10-6135) copies/mL. Using a modified intent-to-treat analysis (US Food and Drug Administration Snapshot method), 28 of 30 (93.3%; 95% confidence interval, 77.9%-99.2%) had viral suppression at 48 weeks. The 1 subject with virologic failure had multidrug-resistant HIV-2 (reverse transcriptase mutation: K65R; integrase mutations: G140S and Q148R) detected at week 48. There were 8 grade 3-4 adverse events; none were deemed study related. Adherence and acceptability were good.

Conclusions: Our data suggest that E/C/F/TDF, a once-daily, single-tablet-regimen, is safe, effective, and well tolerated. Our findings support the use of integrase inhibitor-based regimens for HIV-2 treatment.

Clinical trials registration: NCT02180438.

Figure 1.

Modified intent-to-treat analysis of CD4 cell count trajectory of human immunodeficiency virus type 2 (HIV-2)–infected patients on elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (E/C/F/TDF) from week 0 to week 48 (n = 29/30). Missing CD4 data at week 0 (n = 1). Bars indicate median CD4 count change from baseline (with interquartile range).

Figure 2.

Modified intent-to-treat analysis (with 95% confidence interval [CI]) of virologic suppression (human immunodeficiency virus type 2 [HIV-2] plasma viral load <50 copies/mL) of HIV-2–infected patients on elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (E/C/F/TDF) over 48 weeks (n = 30). Events: HIV-2 >50 copies/mL (weeks 36 and 48, n = 1), noncompleter (n = 1), missing (week 12, n = 1).