Population-level impact of expanding PrEP coverage among men who have sex with men with long-acting injectable cabotegravir: model comparison analysis for Atlanta, US and Montreal, Canada

Title

Population-level impact of expanding PrEP coverage among men who have sex with men with long-acting injectable cabotegravir: model comparison analysis for Atlanta, US and Montreal, Canada

Presenter

Sarah Stansfield

Authors

S. Stansfield * (1), K.M. Mitchell (2), C.M. Doyle (3), R.M. Milwid (3), M. Moore (1), J. Heitner (4), D. Donnell (1), M. Maheu-Giroux (3), M.-C. Boily (2), D. Dimitrov (1)

Institutions

(1) Fred Hutchinson Cancer Research Center, Seattle, United States, (2) Imperial College London, London, United Kingdom, (3) McGill University, Montreal, Canada, (4) University of Washington, Seattle, United States

BACKGROUND: Long-acting injectable cabotegravir (CAB-LA) demonstrated superiority to daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for HIV pre-exposure prophylaxis (PrEP) in the HPTN 083/084 trials and is currently approved for HIV prevention in the United States. We compared the potential impact of expanding PrEP coverage by offering CAB-LA to men who have sex with men (MSM) in Atlanta, US/Montreal, Canada, cities with different HIV epidemics.
METHODS: Two age- and risk-stratified HIV transmission models were independently parameterised and calibrated to local data. Scenarios achieving 40% and 50% PrEP coverage after 5 and 10 years by switching 0%-50% of TDF/FTC users to CAB-LA in 2022 and recruiting additional CAB-LA users were simulated. Intervention impact was measured as the proportion of cumulative HIV infections averted over 20 years compared to base-case scenarios with TDF/FTC use only (median values presented).
RESULTS: Model simulations predict that, in the base-case without CAB-LA, overall PrEP coverage in Atlanta/Montreal could reach 32%/10% by 2042 with HIV prevalence decreasing to 17%/2%. Achieving 40% PrEP coverage in 2027 by adding CAB-LA is expected to avert 37%-40% of new HIV infections over 20 years in Atlanta and 47% in Montreal (Figure). Switching TDF/FTC users to CAB-LA (0% vs 50%) has a modest impact (~3 percentage points increase (pp)) in Atlanta with no clear effect in Montreal where base-case PrEP coverage is significantly lower. Delaying achieving 40% coverage until 2032 reduces the impact by 4pp and 9pp in Atlanta and Montreal, respectively. Reaching 50% PrEP coverage in 2027 increases the impact in Atlanta by 16pp-18pp and by 8pp-10pp in Montreal compared to 40% coverage.

CONCLUSIONS: Achieving high PrEP coverage by offering CAB-LA could impact the HIV epidemics substantially if rolled out without delays. Recruiting additional new CAB-LA users is expected to have a greater impact on preventing new HIV infections than switching current TDF/FTC users to CAB-LA.

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