OBJECTIVES: To evaluate the potential epidemiological and economic impact of early initiation of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF), the only single-tablet regimen recommended for rapid initiation in diagnosed patients, on HIV transmission compared with the current antiretroviral therapy (ART) initiation observed in clinical practice in the Kingdom of Saudi Arabia (KSA).

METHODS: A previously developed transmission model was adapted to estimate the cumulative HIV infection incidence and potential cost savings based on the number of HIV infections prevented over a 10-year period. The analysis compared early treatment initiation with B/F/TAF (7 days from diagnosis until treatment) versus current ART practice (29 days). The model used one-year cycles, consisting of a prevalent population of Saudi men and women living with HIV that were divided between different health states, each with a different risk of transmission. Infectious individuals contributed to the incidence of new infections in that year via their risk of transmission estimated by sexual contact. HIV lifetime cost (USD, 2021) included direct costs of HIV management.

RESULTS: In the base-case analysis, early therapy initiation with B/F/TAF was estimated to prevent 157 new HIV infections over the next 10 years compared to late initiation with a pool of INSTIs, NNRTIs and PIs. Considering the lifetime costs (SAR 1,724,208 = $459,530/person) of treating the infections avoided over the next 10 years, the reduction in the HIV incidence could result in potential savings of SAR 269,966,756 ($71,950,649). According to OWSA results, besides the time horizon, the time for ART initiation was the parameter with the highest impact on HIV incidence.

CONCLUSIONS: The ART rapid initiation in newly diagnosed patients is a high value strategy for the KSA national health system. Rapid initiation with B/F/TAF contributes to the reduction in HIV incidence and related costs as demonstrated by the model results.