CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

893

Body Composition Changes in People With HIV Switching From or Maintaining TDF-Based Regimens Jovana Milic 1 , Stefano Calza 2 , Stefano Renzetti 2 , Federico Motta 1 , Gianluca Cuomo 3 , Marianna Menozzi 3 , Giuseppe Mancini 1 , Cristina Mussini 1 , Giovanni Guaraldi 1 1 University of Modena and Reggio Emilia, Modena, Italy, 2 University of Brescia, Brescia, Italy, 3 AOU Policlinico di Modena, Modena, Italy Background: Weight gain might occur in people with HIV (PWH) switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF)-based antiretroviral therapy (ART), but data regarding body composition are missing. The objective of the study was to explore body composition (BC) changes in PWH switching from or maintaining TDF-based ART. Methods: This was an observational longitudinal study including ART experienced PWH attending the Modena HIV Metabolic Clinic (Italy) from 2004 to Feb 2024 with at least 3 assessments for BC, measured by dual energy X-ray absorptiometry (DEXA). BC comprised total lean and fat mass, including trunk fat. Baseline (time 0, T0) was defined as the first available DEXA in which TDF-based ART was recorded. In the switching groups, time 1 (T1) was the date of switching to TAF (group 2) or abacavir (ABC) and/or lamivudine (3TC)-based ART (group 3), while in PWH who maintained TDF (group 1) was the closest date to other two groups. Groups were matched for median time duration between T0 and T1. Time 2 (T2) was defined as 2 years after the switch in all groups. The effect of switching from or maintaining TDF on BC changes was explored in the linear mixed model (LMM) adjusted for age and sex. Results: A total of 1235 PWH were included (29.5% women). At T0, median age was 45 yrs, median BMI was 23.4 kg/m2, median CD4 cell count 590 c/microL. At T1, groups 2 and 3 were older (Group 1, 2, 3: 48, 53, 50 yrs) and had higher: BMI (Group 1, 2, 3: 23.6, 24.5, 23.4 kg/m2), total fat (Group 1, 2, 3: 15, 21, 16 kg) and trunk fat (Group 1, 2, 3: 8, 8.6, 11 kg) compared to Group 1 (all p<0.001). No differences were observed in total lean mass among the groups at T1. After a follow-up of 2 years, differences were observed in BMI (Group 1, 2, 3: 23.6, 24.5, 23.5 kg/m2), total (Group 1, 2, 3: 16, 21, 17 kg) and trunk (Group 1, 2, 3: 8.4, 10.8, 9.1 kg) fat mass (all p<0.001). In LMM, at T2, trends for BMI and lean mass increase were significantly higher in PWH switching to TAF or ABC and/or 3TC when compared to PWH maintaining TDF (Table 1). Conversely, trends for total fat and trunk increase were higher in PWH maintaining TDF when compared to switching to TAF (Table 1). Trends over time for BC changes among the groups is shown in Table 1. Conclusions: After 2 years of follow-up, maintaining TDF was associated with decrease in BMI and total lean mass, suggesting that weight loss observed with TDF regimens might be related to unhealthy lean loss.

892

Weight Change on F/TAF vs Placebo: Using Common F/TDF Groups to Bridge Data Across Clinical Trials David Glidden 1 , Andrew Whiteman 2 , Yuan Tian 2 , Joshua Gruber 2 , Cal Cohen 2 , Andrea Marongiu 1 University of California San Francisco, San Francisco, CA, USA, 2 Gilead Sciences, Inc, Foster City, CA, USA Background: The impact of antiretrovirals on body weight in people with HIV is unclear. Reversible weight-suppressive effects of emtricitabine/tenofovir disoproxil fumarate (F/TDF) have been demonstrated, while effects of emtricitabine/tenofovir alafenamide (F/TAF) are debated. Comparison of F/TAF with placebo in people without HIV may give valuable insight into F/TAF’s effect on weight. We used data from pre-exposure prophylaxis efficacy studies to compare weight gain with F/TAF vs placebo among people without HIV. Methods: Data from 2 randomized clinical trials were used: iPrEx (NCT00458393; F/TDF vs placebo; N=2499) and DISCOVER (NCT02842086; F/ TAF vs F/TDF; N=3573). Weight was measured during regular study visits. The common F/TDF groups were used to bridge studies and compare mean weight change on F/TAF to placebo. Participants from countries not represented in the iPrEx placebo sample were excluded from this analysis (European sites from DISCOVER). Sensitivity analyses were limited to participants from North America and DISCOVER participants who used F/TDF at baseline (BL). Results: DISCOVER participants were older, more likely of White race, had higher body mass index at BL, and more frequently used medication associated with weight change vs iPrEx participants. After adjusting for differences in demographics across trials, estimated mean weight change with F/TDF was similar between studies ( Figure ). Weight change from BL in participants on F/ TAF with no prior F/TDF use (n=1422) was similar to placebo ( Figure ); there were no statistically significant differences in mean (95% CI) weight change at Week (W) 48 (+0.44 [-0.04, 0.92] kg) and W96 (+0.53 [-0.28, 1.34] kg). Among DISCOVER participants who switched from F/TDF to F/TAF (n=360), differences in mean weight change vs placebo were larger: +1.15 (0.53, 1.77) kg at W48 and +1.74 (0.78, 2.70) kg at W96. Results were consistent when restricted to North American participants and when using different model and sample weighting approaches. Conclusions: This is the first analysis comparing changes in weight with F/ TAF vs placebo. The observed weight trajectories in the 2 study samples with F/ TDF were nearly overlapping, supporting the general validity of our cross-trial comparison. Greater weight gain among those who switched from F/TDF was consistent with a reversible weight-suppressive effect of F/TDF. Similar observed weight change with F/TAF and placebo in people without HIV suggests no clinically meaningful effect of F/TAF on weight gain.

Poster Abstracts

894

Risk Factors Associated With Extreme Weight Gain in People With HIV Laven Mavarani 1 , Sarah Albayrak-Rena 1 , Stefanie Sammet 1 , Felix Maischack 1 , Anja Potthoff 2 , Martin Hower 1 , Andreas Schoenfeld 1 , Dirk Schadendorf 1 , Boerge Schmidt 1 , Stefan Esser 1 , for the HIV HEART Aging Cohort Study Group 1 University Hospital Essen, Essen, Germany, 2 Ruhr-University Bochum, Bochum, Germany Background: Increasing prevalence of obesity has been observed among people with HIV (PWH). Weight gain is a multifactorial process. This study evaluates potential factors for weight gain over 5 years in PWH. Methods: The HIV-HEART (HIVH) cohort is a prospective study assessing cardiovascular risk of PWH in the Ruhr area of Germany since 2004. PWH with weight measurements at two different time points in 5 years were included in this analysis. To assess risk factors for weight gain, logistic regression adjusted for baseline age, sex, and duration of HIV was used to compare participants with a weight gain of ≥10% (group A, N=212) versus a stable weight from 0 to ±5% (group B, N=974) within 5 years. Odds ratios (OR) and corresponding 95% confidence limits (Cl) were presented. For continuous factors, the OR was shown per standard deviation (SD). Variables were considered at baseline (BL). For the

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