CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

healthcare perspective, as compared to CE thresholds ($590-$3525/DALY for South Africa and $500-$750 for other settings). One-way sensitivity analyses included CE threshold, DSD effectiveness, cost, and disability weight. Results: CAG was cost-effective for all country/model settings under upper CE thresholds (ICERs: $295– $678/DALY). UAG yielded higher DALYs averted at higher costs than CAG (ICERs: $512–$773/DALY). In all settings, HomeART was dominated by UAG. All ICERs decreased with longer time horizons of analysis, making DSD cost-effective over 30 to 40 years, depending on the setting. CE of CAG remained robust in sensitivity analyses on DSD effectiveness, cost, and disability weight, except when effectiveness decreased from 25% to 10% in Malawi. However, CE of UAG and HomeART was sensitive to the aforementioned three factors. Conclusion: CAG and UAG can provide cost-effective alternatives to the SoC clinical-based HIV treatment in SSA, depending on the setting and time horizon of interest. These findings support current efforts to scale DSD in SSA. 1230 Model Comparison of the Cost-Effectiveness of Long-Acting Cabotegravir for HIV PrEP in South Africa Jesse A Heitner 1 , Sarah Stansfield 2 , Lise Jamieson 3 , Gesine Meyer-Rath 4 , Leigh F. Johnson 5 , David Kaftan 6 , Anna Bershteyn 7 , Jennifer Smith 8 , Valentina Cambiano 8 , Loveleen Bansi-Matharu 8 , Andrew Phillips 8 , Mia Moore 2 , Ruanne V. Barnabas 1 , Marie-Claude Boily 9 , Dobromir Dimitrov 2 1 Massachusetts General Hospital, Boston, MA, USA, 2 Fred Hutchinson Cancer Center, Seattle, WA, USA, 3 University of the Witwatersrand, Johannesburg, South Africa, 4 Boston University, Boston, MA, USA, 5 University of Cape Town, Cape Town, South Africa, 6 New York University, New York, NY, USA, 7 New York University Langone Medical Center, New York, NY, USA, 8 University College London, London, United Kingdom, 9 Imperial College London, London, United Kingdom Background: Long-acting injectable cabotegravir (CAB-LA) is superior to oral emtricitabine / tenofovir disoproxil fumarate (TDF-FTC) for HIV pre-exposure prophylaxis (PrEP) and has the potential to expand PrEP usage. Evaluation of the cost-effectiveness (CE) in sub-Saharan Africa is needed to optimize health resource allocation. Methods: Three independent age- and risk-stratified HIV transmission models (EMOD-HIV, Synthesis, and Thembisa) were calibrated to epidemiological data for South Africa. Expanding PrEP usage to 5, 10, or 15% of the sexually active population via leveraging CAB-LA to supplement and increasingly replace TDF-FTC within 5 or 10 years and sustaining initiations until 2042 was simulated and compared to status quo PrEP use. Use by risk exposure varied by model. Effects were assessed in disability-adjusted life years (DALYs) over 50 years. Costs incorporated PrEP provision, outpatient antiretroviral therapy provision, and HIV-related inpatient costs by CD4 count. The potential annual total delivery cost of CAB-LA was varied from 1 to 50 times that of TDF- FTC's (US$124). Costs and DALYs were discounted at 3%/year. An empirically estimated CE threshold of US$3,767/DALY was utilized. Results: All models showed diminishing CE with higher PrEP usage, at least partly because higher usage reaches more people with lower risk. Expansions in 5 vs 10 years typically had similar CE, with Thembisa showing the largest differences in favor of 5 years. On average, 5% usage in 5 years had the best CE and 15% in 10 the worst. With Thembisa, the median CE for 5% in 5 years was $605/DALY if CAB-LA is delivered at cost parity with TDF-FTC, and $49,617/ DALY at 50-fold costs, compared to $1,076 and $72,147, respectively, if 15% PrEP usage is reached within 10 years. Compared to Thembisa, the EMOD-HIV and Synthesis models assumed more risk-informed PrEP delivery, modeled lower HIV incidence declines without CAB-LA, and had higher continuing TDF-FTC provision. Both projected expanding PrEP use with CAB-LA to be cost-saving if delivered at cost parity with TDF-FTC under all scenarios. At 50-fold costs, median estimates were $3,206 and $6,845/DALY at 5% PrEP usage in 5 years and $6,135 and $21,782 at 15% usage in 10 years for EMOD-HIV and Synthesis, respectively. Conclusion: Three independent models predict expanding PrEP coverage with CAB-LA would be cost- effective if delivered at a cost near that of TDF-FTC, and highlight the importance of reaching people with high risk for CE at higher prices.

1231 Cost-Effectiveness of a Urine Tenofovir Point-of-Care Assay for ART Adherence Feedback in Namibia Ntombizodwa M Nyoni 1 , Sigal Maya 1 , Jacques Kamangu 2 , Daniella Mouton 3 , Assegid Mengistu 2 , Matthew A. Spinelli 1 , Pearl Kalimugogo 4 , Gram Mutandi 4 , Steven Y. Hong 4 , Jim Kahn 1 , Peter Minchella 4 , Monica Gandhi 1 , Leonard T. Bikinesi 2 1 University of California San Francisco, San Francisco, CA, USA, 2 Ministry of Health and Social Services, Windhoek, Namibia, 3 Namibia Institute of Pathology, Windhoek, Namibia, 4 Centers for Disease Control and Prevention, Atlanta, GA, USA Background: Virologic failure (VF) in patients on TLD often results from non adherence given dolutegravir's high resistance barrier. Real-time adherence measurement could improve counseling, help patients achieve virological suppression (VS), reduce viral load (VL) tests, and promote cost-effective (CE) adherence interventions. In Namibia, we found that a new point-of-care (POC) urine-based tenofovir (TFV) assay-based intervention increased VS to 90% among those with VF on TLD after 3 months of WHO-recommended enhanced adherence counseling (EAC). These results contrast with an overall 71% VS rate worldwide for those on ART as estimated by the UNAIDS July 2023 report. Methods: We modeled the health and cost impacts of two possible implementation scenarios with the urine assay over a year, comparing them to the standard of care (SoC) involving monthly EAC alone for VF, with VL tests every 3 months. Scenario 1 involved monthly TFV POC testing and EAC with a VL test after 3 consecutive positive POC tests; scenario 2 further restricted the use of VL testing to patients with no record of VS throughout the intervention period and an assumption that those who achieved VS remained adherent for a year. In 2020, the cost of VL and TFV POC testing was $63 and $1.33, respectively, for both SoC and the two scenarios. The cost of EAC ranged from $1.17 to $1.92 based on duration of session. Baseline ART adherence and VS data were obtained from the clinical study and UNAIDS. We assumed no patients would drop out of care. Results: When following SoC guidelines, in a hypothetical cohort of 100 patients with VF on TLD, EAC alone increases VS to 71% at a total cost of $27,348. Scenario 1, in which POC tests were used to determine eligibility for VL tests, saved a total of 46 VL tests with a cost-savings of $2000, and resulted in 97% adherence and 90% VS. Scenario 2, where VL testing was not performed after VS was achieved, averted another 242 VL tests and an additional $15,190 (Table). It was assumed this large reduction in VL testing would not impact overall VS rates. Conclusion: The study evaluates the cost and cost-effectiveness of incorporating a POC urine TFV test into counseling for ongoing viremia on TLD; the intervention was less expensive and improved health compared to SoC. An upcoming clinical trial will compare SoC EAC to urine assay counseling in a large sample with further CE analysis with hopes of eventual wide implementation of the urine assay worldwide to reduce VF, viral resistance, and transmission.

Poster Abstracts

CROI 2024 403