CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

Conclusions: While HIV services remain resilient in supporting the aging DTP population, there is a significant disconnect between HIV care and other critical services, particularly for aging and migrant populations. These service gaps may pose long-term challenges to the sustainability of the broader healthcare system and require urgent attention.

1291 Model-Projected Costs Associated With Increasing Numbers of Medicare Beneficiaries With HIV Aged 65+ Emily Hyle 1 , Parastu Kasaie 2 , Luke Ang 1 , Elizabeth Humes 2 , Jessica Phelan 3 , Lucas Gerace 2 , Ciara Duggan 3 , Florence Ebem 1 , John Orav 4 , Ankur Pandya 3 , Tim Horn 5 , Jose Figueroa 3 , Keri N. Althoff 2 , Kenneth A. Freedberg 1 1 Massachusetts General Hospital, Boston, MA, USA, 2 The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA, 3 Harvard TH Chan School of Public Health, Boston, MA, USA, 4 Brigham and Women's Hospital, Boston, MA, USA, 5 National Alliance of State & Territorial AIDS Directors, Washington, DC, USA Background: As people with HIV (PWH) in the US continue to age, costs to Medicare are expected to rise substantially. We projected the number of 65y+ Medicare beneficiaries with HIV in the US from 2023 to 2033 and the potential budget impact on Medicare. Methods: We used the CEPAC microsimulation model of HIV disease and treatment with CDC population estimates and simulated Medicare beneficiaries with HIV aged 65y+ and on ART from 2023-2033. We accounted for PWH already in care turning 65y and new HIV diagnoses in people 65y+. Annual, age-stratified costs were derived from 2014-2018 Traditional Medicare (TM) claims data for people filling ART prescriptions for ≥10 months per year: ART ($31,000-34,400), direct HIV-related care ($2,200-2,800), and other clinical care costs ($19,300-20,100). For people dying during the simulation period, we incorporated age-stratified TM claims in the 12m prior to death: ART ($29,400 31,600), direct HIV-related care ($9,900-17,200), and other care costs ($51,100 66,400). We performed sensitivity analyses on key parameters and assumptions, including a 40-90% reduction in ART prices given the possibility of generic ART regimens or price negotiation under the Inflation Reduction Act. Model outcomes included numbers of PWH aged 65y+ in Medicare and undiscounted dollars spent by Medicare from 2023-2033. Results: We projected that 130,750 PWH would meet age-eligibility criteria for Medicare in 2023 (65-69y: 66,110; 70-74y: 39,320; 75-79y: 17,490; 80y+: 7,830) (Figure, Panel A). By 2033, this number would nearly double to 252,350 (65-69y: 99,950; 70-74y: 80,560; 75-79y: 44,320; 80y+: 27,520). Costs to Medicare for PWH 65y+ would rise substantially, from $7.9 billion in 2023 to $15.2 billion in 2033, with over 50% contributed by ART costs (Figure, Panel B). If ART prices are reduced by 50%, Medicare would save $33.7 billion over the 10y period, lowering ART costs to 33% of overall expenditures. Conclusions: The number of 65y+ Medicare beneficiaries with HIV is likely to double over the next decade, reaching $15.2 billion in annual costs to Medicare by 2033; these projected costs do not include additional costs of Medicare eligible PWH under age 65 or variation in costs among PWH on Medicare Advantage instead of TM. Reductions in ART prices could lead to substantial decreases in overall Medicare spending for older beneficiaries with HIV. The figure, table, or graphic for this abstract has been removed. 1292 Modeling the Impact of Increased PrEP Use on Sexually Acquired HIV Incidence in the United States Benjamin La Brot 1 , Jason Baron 1 , Tamar Tchelidze 1 , Nicole Robinson 2 , Aniruddha Hazra 3 , Kenneth Mayer 4 1 Roche Diagnostics, Somerville, NJ, USA, 2 Roche Laboratories, Indianapolis, IN, USA, 3 University of Chicago Medical Center, Chicago, IL, USA, 4 The Fenway Institute, Boston, MA, USA Background: In 2015, the CDC estimated that 1.2 million Americans could benefit from PrEP; however, this may now be outdated, particularly given ambitious CDC HIV elimination goals. Methods: Using responses to the most recent suitable NHANES survey (2015/16), including respondent age and sex, number and sex of sexual partners, number of times having sex, condom use frequency, prior anal sex and partners 5+ years older/younger, we stochastically imputed survey respondents’ detailed sexual practices over the prior year. This included the age and state of each sexual partner and the sexual acts (counts, activities, condom use) with each partner. Using CDC-disseminated estimates of HIV risk per sexual act, we calculated each respondent’s total HIV acquisition risk (prior year), conditioned on their partners’ HIV/STI statuses. We generated a probabilistic distribution for each HIV/STI status for each partner using CDC prevalence/ incidence data, partner age, sex, and state, and a calibration parameter reflecting national HIV incidence. By aggregating respondents’ conditional HIV acquisition risks over the partner HIV/STI status probabilities, we estimated each respondent’s overall sexually-acquired HIV risk. We translated HIV risk into expected incidence and scaled to the US population 18-59, incorporating survey

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1290 Estimated Benefits of Providing On-Demand PrEP Options for Women in Cape Town: A Modeling Study Sarah Stansfield 1 , Mia Moore 1 , Marie-Claude Boily 2 , Jim Hughes 3 , Deborah J. Donnell 1 , Linda-Gail Bekker 4 , Dobromir Dimitrov 1 1 Fred Hutchinson Cancer Center, Seattle, WA, USA, 2 Imperial College London, London, UK, 3 University of Washington, Seattle, WA, USA, 4 Desmond Tutu HIV Foundation, Cape Town, South Africa Background: Daily and on-demand oral pre-exposure prophylaxis (PrEP) have been shown to be effective at preventing HIV acquisition among cisgender men and transgender women, but only daily PrEP is recommended for cisgender women. On-demand PrEP may be a valuable option to improve PrEP uptake, effective use, and persistence in cisgender women. We use data from HPTN 067 study to estimate effectiveness achieved by different non-daily PrEP options and investigate which sub-groups of women may benefit most from using them. Methods: We created a synthetic cohort of PrEP users using data on the frequency of sex acts, condom use, and PrEP pill taking from the Cape Town site of the HPTN 067 study. We simulated PrEP use and HIV incidence with hypothetical use of the three PrEP regimens tested in HPTN 067: daily, time based (2 pills/week +1 pill after sex), and event-based (1 pill before +1 pill after sex) PrEP, as well as 2-1-1 (2 pills before +1 pill each of the following two days after sex) PrEP for six months each. We estimated PrEP effectiveness based on the number of pills taken around sex acts. Adherence to 2-1-1 PrEP, which was not tested in the HPTN 067, was informed by observed adherence to event based PrEP. Assignment to 2-1-1 PrEP based on daily PrEP adherence, sex act frequency, and hypothetical “optimal” criteria combining better effectiveness and/or lower pill burden were also analyzed. Results: We estimated effectiveness of 81% for daily, 46% for time-based, 42% for event-based, and 59% for 2-1-1 PrEP for HPTN 067 participants in Cape Town (see Figure). PrEP users with low adherence to daily PrEP (less than 2.8 pills per week) benefited most from non-daily PrEP. In this subgroup, comprising 8% of the cohort, PrEP effectiveness increased from 39% to 43% when switching from daily to 2-1-1 PrEP while pill taking decreased from 2 to 1.5 pills per week. We found no advantage in assigning 2-1-1 PrEP by sex act frequency. The effectiveness of hypothetical “optimal” assignment was comparable to assignment based on low PrEP adherence. Conclusions: On-demand PrEP could benefit women with low daily PrEP adherence by decreasing the number of days on which pills need to be taken and increasing effectiveness compared to a daily regimen. This would be a valuable and easy-to-implement additional option in places where daily oral PrEP is already available.

Poster Abstracts

CROI 2025 428