Effectiveness of second-line antiretroviral therapy: the impact of drug switches

ABSTRACT

Including antiretroviral drug switches as a measure of ART failure could be more suitable than conventional measures to evaluate health outcomes in “real-world” settings. This is part of a historical cohort of HIV-infected adults who initiated ART from 2001–2005, and were followed up for a maximum of five years in three HIV/AIDS centers in Belo Horizonte, Brazil. Follow-up information included data from 2001–2010. All patients switched from first-line ART were included. Second-line ART effectiveness was measured as the time-to-ART failure. Failure was defined simulating two scenarios: (1) Clinical, immunological and virological failure (scenario 1); and scenario 1 plus ART switches (scenario 2). Descriptive analysis, Kaplan-Meier curves, log-rank test, and Cox proportional hazards model were performed. We identified 119 eligible patients; most had protease inhibitor (PI)-based regimens prescribed as second-line. The incidence of failure was different for the two scenarios (29.4% vs. 54.6% for scenario 1 and 2, respectively; p < 0.001). The main identifiers of failure were increase in viral load (31.1%) for scenario 1 and ART switches (42.8%) for scenario 2. Median duration on second-line ART was 36.8 vs. 19.8 months for scenario 1 and 2, respectively. In the Cox analysis of scenario 2, increased risk was found for patients given PI-based second-line regimens (HR = 2.26; 95% CI: 1.09–3.17). There is a high incidence of ART failure associated with PI-based regimens when ART switches are considered as an indicator of failure. This demonstrates the impact of ART switches in representing lack of ART effectiveness.

KEYWORDS:

• HIV/AIDS
• antiretroviral therapy
• therapeutic failure
• effectiveness
• cohort studies

Ackowlegments

The authors are grateful to collegues from the class of Writting Papers Tecniques at School of Pharmacy from UFMG, for the valuable contributions to the discussion of this paper and to Leonardo Bahia Tavares for figure editing. The authors also gratefully acknowledge the financial support from Pró-Reitoria de Pesquisa – PRPq, Universidade Federal de Minas Gerais (UFMG), for language editing of the manuscript, and for the contribution from the HIV/AIDS referral centers. Authors are also grateful to Dr. Rodrigo Maia de Pádua in the figure editing for better resolution.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Letícia Penna Braga http://orcid.org/0000-0001-9754-356X

Additional information

Funding

This work was supported by Fundação de Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG [grant number APQ0043-10]; Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq [grant number 484865/2011-0]; Pró-Reitoria de Pesquisa PRPq/UFMG.