Cohort of Women Living With HIV-1 and Receiving Bictegravir/Emtricitabine/Tenofovir Alafenamide

Biktarvy® is a widely prescribed antiretroviral (ARV) medication used for the treatment of HIV-1, formulated as a single-tablet regimen. This combination therapy consists of three potent antiretroviral drugs: bictegravir (BIC/B), an integrase strand transfer inhibitor (INSTI); emtricitabine (FTC/F), a nucleoside reverse transcriptase inhibitor (NRTI); and tenofovir alafenamide (TAF), the novel prodrug of tenofovir, another NRTI. This tablet (B/F/TAF) is a first-line treatment option recommended by most international guidelines for adults living with HIV. B/F/TAF is widely prescribed due to its high potency, excellent tolerability, and convenient once-daily dosing schedule.

The landscape of HIV management in pregnancy has undergone significant transformation since the mid-1990s. Guidelines for HIV screening during pregnancy, treatment of HIV-positive pregnant individuals, and the use of ARV drugs for prevention of perinatal (vertical) and postnatal HIV transmission have evolved substantially. Current guidelines recommend that pregnant women with HIV receive effective ARV therapy for maternal health and to avoid perinatal transmission; however, recommended treatment options differ in pregnancy due to concerns of toxicity, lower drug exposures, teratogenicity, or lack of information. Recently, pharmacokinetic, efficacy, and teratogenicity data have become available for B/F/TAF when used in pregnancy, and demonstrate consistently that while PK concentrations are lower, viral suppression (VS) is not affected. In response, some guidelines now list B/F/TAF as an alternative regimen to be used in pregnancy but recognize that data are still limited to make this a preferred regimen. French guidelines however, take a more conservative approach, listing BIC among drugs to avoid during pregnancy due to insufficient safety data.

Research question and objectives This retrospective multicentric, multinational observational cohort study is conducted in two distinct parts to evaluate B/F/TAF use in pregnant women with HIV-1.

Part 1: Aims to describe the patterns of B/F/TAF use in women with HIV-1 who received B/F/TAF for at least 30 days at any point during pregnancy. This will be a descriptive analysis of initiation and switch patterns among those exposed to B/F/TAF during pregnancy, and demographics/immunological/clinical characteristics. The reasons for switching B/F/TAF to other ARV treatments during pregnancy will be explored.

Part 2: Aims to describe viral, pregnancy and neonatal outcomes in a subset of women already on B/F/TAF treatment at conception with VS at the first trimester of pregnancy, and among those who continued to receive B/F/TAF through delivery, or switched to another regimen.