Dosing of ritonavir-boosted darunavir for treatment of HIV in pregnancy

OBJECTIVE: To assess the effectiveness of once- and twice-daily ritonavir-boosted darunavir (DRV/r)-containing regimens for treating HIV in pregnancy to inform the 2025 World Health Organization antiretroviral treatment guidelines update. DESIGN: Analysis of pooled data from two observational study networks with sites in Romania, Switzerland, and the United Kingdom. METHODS: Pregnancies resulting in a live birth or stillbirth in women receiving 800/100 mg DRV/r once-daily or 600/100 mg twice-daily during pregnancy were included. The primary outcome was viral suppression (<50 copies/ml) near delivery (from 28 days prior to 7 days after delivery). RESULTS: Among 162 women on once-daily DRV/r, 95% were virally suppressed near delivery, with no difference between those on DRV/r from conception (95%, 113/119) and those who started on or switched to DRV/r during pregnancy (95%, 41/43). Among 27 women on twice-daily DRV/r, 78% were virally suppressed near delivery. Most women remained on the same DRV/r regimen until delivery, and there were no vertical transmissions. Darunavir drug concentrations for the limited number of pregnancies with data available fell within the expected ranges. CONCLUSIONS: This analysis provides some reassurance that once-daily DRV/r can be used successfully in pregnancy. However, given the possibility of reduced drug levels in pregnancy with once-daily dosing, viral load monitoring during pregnancy remains essential. Surveillance of pregnancies in women receiving once-daily DRV/r is needed to further support the use of this dosing during pregnancy.