Long-acting antiretroviral formulations (LA-ART), currently in development, aim to achieve monthly or quarterly ART dosing; this could improve health benefits of ART for HIV-infected individuals who have difficulty maintaining daily adherence. We sought to identify the clinical and economic circumstances under which differing clinical roles of LA-ART might be cost-effective in the US.
We used a microsimulation model of HIV disease progression (CEPAC-US) to project the impact of 3 potential roles of LA-ART (compared to daily ART only): 1) initial therapy for all ART-naïve patients, 2) 2nd-line therapy for those failing 1st-line, and 3) use for patients with multiple prior failures on NNRTI- and PI-based regimens. Model outcomes include quality-adjusted life-years (QALYs), lifetime cost, and incremental cost-effectiveness ratio (ICER); strategies with ICER < $100,000/QALY are designated “cost-effective”. We simulate a cohort with mean adherence (medication possession ratio) of 89% (SD = 22%). Depending on adherence, HIV RNA < 400c/mL at 48 weeks on daily ART ranges from 0 to 91%, and loss to follow-up ranges from 41 to 4/100PY. We assume LA-ART's efficacy is 91% regardless of adherence to daily ART, and that LA-ART costs $60,000/patient-year (vs. $28,000 for daily PI-based regimens). In sensitivity analysis, we vary LA-ART's cost, efficacy, and quality of life (QOL) impact (due to benefits of reduced pill burden or detrimental side effects).
In the base case, LA-ART increases overall life expectancy (LE) compared to daily ART by 0.5-0.6 years, and LE of patients with the lowest adherence by 2.3-3.0 years, depending on clinical role; only LA-ART for patients with multiple failures is cost-effective ($86,000/QALY, Table). With a cost of $30,000/year and a favorable QOL impact, 2nd-line LA-ART is cost-effective ($94,000/QALY); varying efficacy of LA-ART has minimal impact on cost-effectiveness results.
LA-ART could improve survival of US HIV patients, especially those with barriers to adherence and poor outcomes on daily ART. With a high cost, it will be a good value for use in patients with multiple prior failures; a cost close to current regimens combined with demonstrable QOL benefit would support broader use.
B. Schackman, None
P. Sax, BMS: Investigator and Scientific Advisor, Grant recipient and Salary
Gilead: Investigator and Scientific Advisor, Research grant and Salary
Janssen: Scientific Advisor, Salary
Merck: Scientific Advisor, Salary
GSK: Investigator and Scientific Advisor, Grant recipient and Salary
A. D. Paltiel, None
R. Walensky, None
K. Freedberg, None
E. Losina, None