HIV Preexposure Prophylaxis in the United States: Impact on Lifetime Infection Risk, Clinical Outcomes, and Cost‐Effectiveness

Abstract

Background The combination of tenofovir and emtricitabine (TDF/FTC) shows promise as HIV pre-exposure prophylaxis (PrEP). We sought to forecast clinical, epidemiologic, and economic outcomes of PrEP, taking into account uncertainties regarding efficacy, risk of resistance and toxicity, behavioral disinhibition, and drug costs. Methods We adapted a computer simulation of HIV acquisition, detection, and care to model PrEP in high-risk (1.6% average annual HIV incidence) men who have sex with men (MSM) in the United States. Base case assumptions included: 50% PrEP efficacy and $753 monthly TDF/FTC costs. We used sensitivity analyses to examine the stability of results and to identify critical input parameters. Results In a cohort with mean age 34 years, PrEP reduced lifetime HIV infection risk from 44% to 25% and increased average life expectancy from 39.9 to 40.7 years (21.7 to 22.2 discounted, quality-adjusted life-years or QALYs). Discounted mean lifetime treatment costs increased from $81,100 to $232,700 per person, indicating an incremental cost-effectiveness ratio (ICER) of $298,000 per QALY gained. Markedly larger reductions in lifetime infection risk (from 43.5% to 5.8%) were observed assuming greater (90%) PrEP efficacy. More favorable ICERs were obtained by targeting younger, higher-incidence populations and with improvements in the efficacy and cost of PrEP. Conclusions PrEP could substantially reduce HIV transmission in high-risk populations in the United States. Although it is unlikely to confer sufficient benefits to justify current TDF/FTC costs, price reductions and/or increases in efficacy could make PrEP a cost-effective option in younger or higher-risk populations. Given recent disappointments in HIV prevention and vaccine development, further study of PrEP-based HIV prevention is warranted.

Assessing the Cost Effectiveness of Pre-Exposure Prophylaxis for HIV Prevention in the US

“…A 2008 study of pre-exposure prophylaxis by Desai and colleagues [50] calculated that the incremental cost per QALY gained in the US was $31,970 (2007 US$), while a year later Paltiel and colleagues [51] calculated that the incremental cost per QALY saved was $298,000 (2006 US$). Both of these studies used HIV transmission and progression models to estimate the cost of reducing the number of new HIV infections, and both used published estimates of the cost of HIV treatment to generate their estimates of the incremental cost of a QALY.…”

Les moyens de prévention de l’infection à VIH à base d’antirétroviraux

“…Par exemple, proposer la PrEP à 60 % des HSH pourrait réduire de 30 à 55 % le nombre de nouvelles infections au cours des dix prochaines années si la PrEP s'avérait efficace à 40-90 % [39]. Cibler une population jeune, et/ou où l'incidence du VIH est plus élevée, et/ou où l'usage du préservatif est faible, et/ou où le taux de dépistage des personnes VIH + reste faible contribuerait à augmenter le rapport coût/efficacité [40]. En effet, l'implémentation de la PrEP dans une population où le taux de dépistage est faible, et donc la proportion de …”

HIV Prevention by Oral Preexposure Prophylaxis

“…Despite the indications of biologic effectiveness, the implementation of PrEP will need to overcome many challenges to provide a meaningful benefit at the population level. Mathematical models have suggested that the effectiveness of PrEP may be offset by low uptake, suboptimal adherence, and risk compensation, which refers to increases in HIVrisk behavior among PrEP users on the assumption that they are protected against HIV infection (Abbas et al 2007;Desai et al 2008;Paltiel et al 2009). As was the case during the implementation of ARV for treating HIV infections, plans for PrEP implementation will likely include multiple components on optimal drug delivery, safety screening, behavioral intervention, integration of PrEP as part of comprehensive care, and monitoring the impact of PrEP at the population level (Underhill et al 2011).…”