Elvitegravir concentrations in seminal plasma in HIV-1-infected men

Abstract

Objectives: The aim of the study was to quantify elvitegravir (EVG) concentrations in the semen of HIV-1-infected men receiving antiretroviral therapy (ART) consisting of an elvitegravir/cobicistat/emtricitabine/tenofovir (EVG/COBI/FTC/TDF) single-tablet regimen. Methods: A phase IV, cross-sectional study was carried out including HIV-1-infected male adults with suppressed plasma HIV-1 RNA who switched ART to EVG/COBI/FTC/TDF. Total EVG concentrations at the end of the dosing interval (C24 h) and HIV-1 RNA were measured in paired seminal plasma (SP) and blood plasma (BP) samples 4 weeks after switching to EVG/COBI/FTC/TDF. Validated liquid chromatography−tandem mass spectrometry (LC-MS/MS) was used to quantify EVG concentrations, and HIV-1 RNA was determined by real-time polymerase chain reaction (PCR). Results: Ten men were included. Their median age was 40 years (range 24–47 years), the median time on ART was 50 months (range 10–186 months), the median time with plasma HIV-1 RNA < 40 copies/mL was 37 months (range 7–113 months), and the median CD4 count was 737 cells/μL (range 190–1122 cells/μL). Four weeks after switching to EVG/COBI/FTC/TDF, all subjects had HIV-1 RNA < 40 copies/mL in both BP and SP. Median EVG C24 h was 277 ng/mL (range 64.8–1790 ng/mL) in BP and 169 ng/mL (range 12.8–792 ng/mL) in SP. A significant correlation was observed between BP and SP EVG concentrations (Spearman rho 0.952; P < 0.001). The median SP:BP EVG concentration ratio was 0.39 (range 0.20–0.92). EVG C24 h in SP was at least 23-fold the in vitro protein-unbound 50% effective response (EC50) of HIV-1 clinical isolates (0.04–0.55 ng/mL). In all but one individual, EVG C24 h in SP was also higher than the blood plasma protein binding-adjusted 95% inhibitory concentration (IC95) of wild-type HIV-1 (45 ng/mL). Conclusions: Seminal EVG concentrations in HIV-infected men treated with EVG/COBI/FTC/TDF sufficed to contribute to maintaining HIV-1 RNA suppression in this compartment.