CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

1008 Impact of Offering PrEP Choice on HIV Incidence in High-Risk Pregnant Women in Kenya Tessa Concepcion 1 , John Kinuthia 2 , Felix Abuna 2 , Eunita Akim 2 , Lauren A. Gomez 1 , Emma Mukenyi 2 , Nancy Ngumbau 2 , Jerusha Mogaka 1 , Ben Ochieng 2 , Monisha Sharma 1 , Grace John-Stewart 1 , Jillian Pintye 1 1 University of Washington, Seattle, WA, USA, 2 Kenyatta National Hospital, Nairobi, Kenya Background: HIV incidence remains a significant concern among pregnant and postpartum women. Offering multiple HIV PrEP options can increase coverage and use, yet the impact of HIV infections averted with implementation of various HIV PrEP options for pregnant/postpartum women is unknown. Methods: We developed an equation to project HIV incidence through pregnancy and postpartum between a reference scenario (oral PrEP only) and five LA-PrEP scenarios: 1) Oral/Ring, 2) Oral/Ring/Injectable, 3) Oral/Ring/ Injectable/Event-Driven, 4) Oral/Ring in pregnancy and Oral/Ring/Injectable/ Event-driven in postpartum, and 5) Ring/Injectable/Event-driven as second-line PrEP (for those who discontinue Oral). The model incorporated uptake rates for different PrEP types, adherence and efficacy estimates, and base HIV risk. Uptake was based on data from a discrete choice experiment among pregnant and postpartum women participating in a PrEP adherence trial in Kisumu and Siaya, Kenya; adherence and efficacy were based on literature. All scenarios were compared to the reference of oral PrEP only. Results: Assuming Oral/Ring availability, resulted in a 23.4% reduction in maternal HIV incidence (50.7 cases averted) and 22.7 cases of VT averted compared to the reference scenario. In the Oral/Ring/Injectable scenario, 40.1% of maternal HIV infections and 38.9 VT cases were averted. Oral/Ring/ Injectable/Event-Driven was associated with 34.8% maternal HIV incidence reduction and 33.5 VT cases averted. Oral/Ring in pregnancy and Oral/Ring/ Injectable/Event-driven in postpartum was projected to reduce maternal HIV cases by 34.5% and VT by 33.6 cases. Ring/Injectable/Event-driven PrEP for those who discontinued Oral resulted in a 25.6% maternal HIV incidence reduction and 24.5 VTs averted. (Figure 1: Reduction in HIV cases and VT across long-acting PrEP scenarios, compared to daily oral PrEP) Conclusions: LA-PrEP formulations achieved greater reductions in total HIV infections and VT compared to oral PrEP only. Scenarios with universally available injectable PrEP, such as Oral/Ring/Injectable and Oral/Ring/ Injectable/Event-Driven, showed the largest reductions. LA-PrEP only offered in postpartum also had substantial reductions. Utilizing LA-PrEP as a second line intervention was better than oral PrEP alone but less effective than more comprehensive approaches. Injectable and event-driven PrEP could reduce maternal HIV, and VT, by up to 40% among high-risk peripartum women and infants.

results to be presented later. This analysis evaluated predictors of recent urine TFV result at 3-months follow-up across arms using logistic regression adjusted for age and gestational age (GA), with the acceptability of urine TFV testing. Results: In n=750 pregnant women, median age was 26 (IQR:22-32); median GA at baseline was 29 weeks (IQR:22-35); 42% were primigravid, 48% had completed secondary or tertiary education, 34% were lowest socio-economic status. At 3-months, n=588 women attended the study visit (78%), 84% reported taking PrEP in the last 30-days (87% in pregnancy, 75% postpartum, p<0.01) and 47% in the last 7-days (n=51% in pregnancy; 39% postpartum, p<0.01). Overall 550 women met criteria and completed a urine TFV test: 49% of women had positive urine TFV results (n=272; 59% in pregnancy vs 42% postpartum; p<0.01). ( Table 1 ).Correlation between reported adherence and urine TFV+ was 0.60. Younger age (<24 vs >24: aOR=1.47;95%CI=1.04-2.06), education (secondary vs primary: aOR=1.47;95%CI=1.04-2.05), earlier GA at enrollment (3rd trimester vs. 2nd trimester aOR=1.85;95%CI=1.32-2.62) and taking PrEP at baseline (vs. not; aOR=1.83;95%CI=1.27-2.64) were associated with urine TFV+ results at 3m follow-up. 11% (40/374) reported taking PrEP in last week with urine TFV- results. Acceptability was high: 99% reported they understood the result, 92% said the result was as expected, 92% expressed satisfaction with the test, 63% reported that the result influenced their adherence. Conclusions: Urine TFV measurement is an acceptable, objective measure of recent PrEP adherence in PPW and can be used to measure recent PrEP use. Postpartum women continue to need additional support for optimal adherence. 1010 TFV-DP Concentrations in PBMCs and Safety of Daily Directly Observed F/ TDF PrEP During Pregnancy Linxuan Wu 1 , Peter Anderson 2 , Nelly Mugo 3 , Matilda Saina 4 , Clare E. Brown 1 , Torin Schaafsma 1 , Katherine K. Thomas 1 , Deborah J. Donnell 5 , Elena A. Rechkina 1 , Bhavna H. Chohan 1 , Kenneth Ngure 3 , Sarah Mbugua 4 , Elex Hill Bachelors 1 , Lane Bushman 2 , Kenneth K. Mugwanya 1 , for the Women Benchmark Study Team 1 University of Washington, Seattle, WA, USA, 2 University of Colorado Anschutz Medical Campus, Aurora, CO, USA, 3 Partners in Health and Research Development, Thika, Kenya, 4 Kenya Medical Research Institute, Kilifi, Kenya, 5 Fred Hutchinson Cancer Center, Seattle, WA, USA Background: Intracellular tenofovir diphosphate (TFV-DP) concentrations from F/TDF PrEP in dried blood spots are ~30-50% lower during pregnancy, but data on TFV-DP levels achieved in peripheral blood mononuclear cells (PBMCs), the clinically relevant site for HIV prevention, are limited. We evaluated the effect of pregnancy on TFV-DP levels in PBMCs and birth and infant growth outcomes in cisgender women using F/TDF. Methods: Directly observed daily F/TDF PrEP was administered to healthy 18 pregnant and 18 non-pregnant Kenyan women for 8 weeks (clinicaltrials.gov: NCT05057858). TFV-DP was quantified in PBMCs collected at week 2, 4, 6, and 8 using validated LC-MS/MS assays at the University of Colorado. Log transformed TFV-DP concentrations were compared between pregnant and non-pregnant groups using linear mixed models adjusted for age and week. Pregnancy outcomes and infant growth in the pregnant group were assessed at 1, 6, and 12 months postpartum and compared to historical controls from the placebo arm (no F/TDF PrEP exposure) of the Partners PrEP Study (NCT00557245). Results: Median (IQR) baseline age and creatinine clearance estimated by cockroft-gault equation was 23 (IQR: 20-27) and 178 (152-198) mL/Min for pregnant and 23 (20-25) and 131 (113-146) mL/Min for non-pregnant women, respectively. For pregnant women, median gestational age was 16 (15-20) weeks. Overall, 137 steady state PBMC samples were analyzed: 68 in pregnant vs 67 in non-pregnant group. Observed geometric mean PBMC TFV-DP levels were 47.8 fmol/10 6 for pregnant vs 55.6 fmol/10 6 in non-pregnant women (Figure 1). Similarly, the fitted mean (95%CI) PBMC TFV-DP concentrations was 47.9 (40.7, 56.2) fmol/10 6 in pregnant vs 55.0 (47.9, 64.6) fmol/106 in non-pregnant women (p=0.17). No preterm birth or birth defects occurred in the PrEP exposed

Poster Abstracts

1009 PrEP Adherence and Acceptability of Urine Tenofovir Testing in Pregnant and Postpartum Women Dvora L. Joseph Davey 1 , Kalisha Bheemraj 2 , Rufaro Mvududu 2 , Nafisa Wara 1 , Sumaya Dadan 2 , Kathryn L. Dovel 1 , Monica Gandhi 3 , Landon Myer 2 1 University of California Los Angeles, Los Angeles, CA, USA, 2 University of Cape Town, Cape Town, South Africa, 3 University of California San Francisco, San Francisco, CA, USA Background: Oral PrEP is effective at preventing HIV in pregnant and postpartum women (PPW). Measuring urine tenofovir (TFV) in people taking PrEP is a new, objective method to evaluate recent PrEP use. We report on rapid urine TFV test acceptability, usability, and results in PPW in a randomized control trial (RCT) in Cape Town, South Africa where urine TFV was used objectively measure adherence in women on PrEP. Methods: SCOPE-PP (Stepped care to optimized PrEP effectiveness in PPW) is an ongoing RCT among PPW on oral PrEP aimed to improve PrEP adherence. Women across arms reporting taking PrEP in the last 7-days received a urine TFV test at baseline and quarterly visits if they report using PrEP in the past 7-days. The intervention arm received biofeedback counseling on the urine test with

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