Investigators said pre-exposure prophylaxis rollout is efficient in settings with high HIV incidence, but not in settings with low HIV incidence.
Introducing long-acting injectable cabotegravir (CAB-LA) as high pre-exposure prophylaxis (PrEP) for HIV without any delays can substantially impact the HIV epidemic, according to the results of a study published by the Journal of the International Aids Society. Additionally, investigators said the PrEP rollout would be efficient in settings with high HIV incidence, but not in settings with low HIV incidence.1
According to the HPTN 083/084 study (NCT02720094), CAB-LA was superior to the daily oral regimen of tenofovir disoproxil fumarate (TDF/FTC) in preventing HIV infection in men who have sex with men and transgender women.Investigators found that the incidence of HIV infection occurred in 13 individuals in the CAB-LA group and 39 in the TDF/FTC group.2
Due to the results, investigators used 3 risk-stratified HIV transmission models to determine the impact of expanding PrEP coverage with CAB-LA in Atlanta, Montreal, and the Netherlands. The models showed an estimated mean of TDF/FTC coverage at 29% in Atlanta, 7% in Montreal, and 4% in the Netherlands in 2022.1
The projected HIV incidence per 100 person per year decreased from 2.06 to 1.62, 0.08 to 0.03, and 0.07 to 0.001, respectively, by 2042, according to the investigators. They expanded on this simulation to include new CAB-LA patients and by switching different proportions of TDF/FTC patients to CAB-LA.1
Further, investigators evaluated the efficacy of PrEP expansions over 20 years in comparison to the baseline scenarios that only included TDF/FTC.1 The results of the study demonstrated an increase of PrEP coverage by 11 percentage points, increasing it from 29% to 40% by 2032.
There was a median 36% of new HIV acquisitions in Atlanta.1 However, investigators reported substantially larger increases in prep coverage, of 40% and 30%, were needed to achieve similar reductions in Montreal and the Netherlands, respectively.1
Further, investigators said that a median of 17 additional person per year were needed to prevent 1 acquisition in Atlanta at 40% coverage compared to 1000 or more in Montreal and 4000 or more in the Netherlands. However, with 50% PrEP coverage by 2023 among new CAB-LA patients among PrEP-eligible men who have sex with men, there could be a reduction of greater than 45% of new HIV acquisitions across all settings, according to the investigators.1 They also noted that when the target coverage was achieved 5 years earlier, there was an increase of approximately 5 to 10 percentage points.1
Additionally, in the Atlanta model, the PrEP expansions for 40% and 50% reduced the differences in PrEP access between White and Black men who have sex with men from 23 to 9 percentage points and 4 percentage points, respectively.1 Investigators concluded that offering CAB-LA to current and prospective patients using PrEP could increase adherence, which would increase the impact of the prophylaxis medication.