Author Interviews, HIV, Pharmacology / 28.11.2016
DTG-Based Medications May Allow Faster Suppression of HIV in Semen
MedicalResearch.com Interview with:
Arkaitz Imaz Vacas
HIV and STD Unit, Department of Infectious Diseases
Hospital Universitari de Bellvitge
MedicalResearch.com: What is the background for this study?
Response: Sexual transmission is the most common route of human immunodeficiency virus (HIV) acquisition in most regions of the world.
The male genital tract is a separate reservoir for HIV and may contribute to HIV shedding in seminal fluid even in individuals receiving antiretroviral (ARV) therapy (ART). Treatment of HIV-infected patients with currently available combined ART suppresses HIV in blood and also in genital fluids and reduces the risk of HIV acquisition by their sexual partners. However, sexual HIV transmission is possible even in patients on ART, especially if treatment was initiated recently. Thus, the ability of ARV drugs to penetrate into the male genital tract is a key factor for achieving HIV suppression in seminal fluid and preventing sexual transmission of the virus.
Dolutegravir (DTG) is a new integrase inhibitor (INI) with high antiviral potency and a high genetic barrier to resistance. In large phase III-a randomized clinical trials, DTG in combination with 2 nucleos(t)ide reverse-transcriptase inhibitors (NRTIs) has shown noninferiority compared with raltegravir and superiority to efavirenz or ritonavir-boosted darunavir as first-line therapy in treatment-naive HIV-1 infected patients. A study in healthy volunteers showed that DTG penetration in seminal fluid was <7% of DTG exposure in blood plasma (BP), and the median seminal concentration at the end of the dosing interval (C24h) was lower than the in vitro protein-adjusted (PA) 90% inhibitory concentration (IC90) for wild-type HIV-1. However, information about protein unbound DTG fraction in seminal fluid is lacking and there is no information regarding DTG concentrations in the semen of HIV-1infected patients or the antiviral activity of a DTG-based ARV combination in this compartment.
The aim of this study was to compare viral decay kinetics and DTG concentrations (total drug and unbound fraction) in the seminal plasma (SP) and BP in a group of treatment-naive HIV-1 infected patients starting DTG plus abacavir (ABC) and lamivudine (3TC) once daily.
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