A Patient-Centered, Combination Intervention to Support Adherence to HIV Pre-exposure Prophylaxis During Pregnancy and Breastfeeding: A Randomized Pilot Study in Malawi

BACKGROUND: Daily oral pre-exposure prophylaxis (PrEP) can reduce HIV incidence in pregnant and breastfeeding women, but adherence is essential. METHODS: We conducted a pilot randomized trial to evaluate an intervention package to enhance antenatal and postnatal PrEP use in Lilongwe, Malawi. The intervention was based on patient-centered counseling adapted from previous PrEP studies, with the option of a participant-selected adherence supporter. Participants were locally eligible for PrEP and randomized 1:1 to intervention or standard counseling (ie, control) and followed for 6 months. Participants received the intervention package or standard counseling at enrollment, 1, 3, and 6 months. Adherence was measured through plasma and intracellular tenofovir concentrations and scored using a published algorithm. Our primary outcome was retention in care with concentrations consistent with 4-7 doses/week. RESULTS: From June to November 2020, we enrolled 200 pregnant women with the median gestational age of 26 (interquartile range: 19-33) weeks. Study retention was high at 3 months (89.5%) and 6 months (85.5%). By contrast, across the 2 time points, 32.8% of participants retained in the study had adherence scores consistent with 2-5 doses/week while 10.3% had scores consistent with daily dosing. For the composite primary end point, no substantial differences were observed between the intervention and control groups at 3 months (28.3% vs. 29.0%, probability difference: -0.7%, 95% confidence interval: -13.3%, 11.8%) or at 6 months (22.0% vs. 26.3%, probability difference: -4.3%, 95% confidence interval: -16.1%, 7.6%). CONCLUSIONS: In this randomized trial of PrEP adherence support, retention was high, but less than one-third of participants had pharmacologically confirmed adherence of ≥4 doses/week. Future research should focus on antenatal and postnatal HIV prevention needs and their alignment across the PrEP continuum, including uptake, persistence, and adherence.