Efficacy and safety of DTG plus 3TC for prophylaxis of perinatal transmission of HIV infection in pregnant women who have detectable viral load after 14 weeks of gestation: A pilot study (PREGNANCY)

Abstract

Abstract Background The prevention of perinatal HIV transmission depends on the safe and effective use of antiretroviral therapy (ART). Simplifying treatment reduces drug exposure for both mother and child. We evaluated the safety and efficacy of DTG/3TC for antiretroviral-naïve pregnant women living with HIV (PWLHIV). Methods This proof-of-concept trial enrolled ART-naïve pregnant women over 15 years old with HIV infection and a gestational age between 14 and 28 weeks. Participants received a fixed-dose combination of DTG/3TC. Baseline HIV genotyping was performed. Participants were monitored at baseline, every 4 weeks, and at delivery. Infants were assessed at birth, 4 weeks, and 6 weeks of age. Outcomes included the proportion of women achieving an undetectable HIV-1 plasma viral load (<50 copies/mL) at delivery, therapy modification frequency, perinatal HIV transmission rate, and adverse events. Results Between January 2019 and March 2021, 20 women were enrolled. At baseline, the median CD4 cell count was 401.6 ± 113.6 cells/μL, increasing to 690.2 ± 266 cells/μL at delivery. Median viral load was 9,514 copies/mL. All women achieved an undetectable viral load after an average of 40 days. No cases of perinatal HIV transmission were detected. No therapy modifications were necessary during the study, and no adverse events were related to the ART. Conclusion In this pilot trial, DTG/3TC demonstrated safety and efficacy, with all participants achieving viral suppression before delivery. There were no cases of perinatal HIV transmission and no drug-related adverse events. DTG/3TC can be an option for initial treatment of drug-naïve PWLHIV.