OBJECTIVES: Clinical investigation in the treatment of HIV has shifted towards the long-term safety profile of antiretroviral therapy (ART) use in people living with HIV (PLHIV). Tenofovir alafenamide (TAF) based ART regimens have shown a more favourable renal and bone safety profile than some of the currently most frequently used non-TAF based ART regimens. This research aimed to estimate the clinical and economic impact of the introduction of TAF based ART regimens, with a focus on the long-term incidence of co-morbidities among PLHIV in Portugal.

METHODS: A de novo patient-level simulation model was developed to simulate the progression of a variety of parameters, related either to viral response or the occurrence of co-morbidities, under different ART regimen sequences. Chronic kidney disease (CKD), cardiovascular disease (CVD) and fracture incidences were driven by published risk equations. Model inputs, assumptions and structure were validated by a national expert panel. TAF-based regimens were compared to tenofovir disoproxil fumarate (TDF) and abacavir (ABC) based regimens for both ART naïve and experienced PLHIV.

RESULTS: For ART naïve PLHIV, the introduction of TAF based regimens was estimated to result in relative reductions in the age-standardized annual incidence of CKD and CVD of up to 30.7% and 29.2%, respectively. For ART experienced PLHIV switching to a TAF based regimen, these estimates go up to 21.2% (CKD) and 15.6% (CVD). No clinically significant relative reductions in the age-standardized annual incidence of fractures were estimated, except for ART naïve PLHIV comparing TAF based to TDF based regimens (4.6%). For ART naïve PLHIV, average life-time per-patient co-morbidity-related cost savings of up to €6,395 could be obtained, whereas for ART experienced PLHIV, this estimate goes up to €1,981.

CONCLUSIONS: The introduction of TAF based ART regimens in Portugal is estimated to result in significant clinical and economic benefits for PLHIV.