Broadening the perspective when assessing evidence on boosted protease inhibitor-based regimens for initial antiretroviral therapy

Several national and international guidelines recommend the use of antiretroviral therapy containing a protease inhibitor (PI) with ritonavir (RTV) boosting for human immunodeficiency virus (HIV)-infected treatment-naïve patients. RTV-boosted PIs such as lopinavir (LPV/r), atazanavir (ATV + RTV), darunavir (DRV + RTV), fosamprenavir (FPV + RTV), and saquinavir (SQV + RTV) are usually recommended in regimens for initial therapy. The guideline recommendations are generally based on the clinical efficacy of the regimens. A broadened perspective of assessing the evidence related to selection of a PI for optimal first-line therapy might consider additional factors for evaluation, such as effectiveness in actual clinical practice and costeffectiveness of individual drugs in formulating recommendations. Among the guidelinerecommended PIs, LPV/r is one of the earliest PIs approved, has been a well-recognized boosted PI for treatment-naïve patients in all guidelines, and demonstrates the most evidence on long-term clinical and economic effectiveness. Studies have shown its efficacy in various controlled and real-world settings in different populations, the relationship of adherence to virologic efficacy, and the implications of resistance when used in sequence with other PI regimens. In the absence of published evidence for other guideline-recommended PIs that will greatly facilitate a fully transparent, comparative effectiveness evaluation, the cumulative evidence from this broader perspective indicates all PIs should not be viewed as equally safe and effective across all patients for initial therapy, nor should any single PI within the class be considered preferred for all treatment-naïve patients.