The clinical role and cost-effectiveness of long-acting antiretroviral therapy

Abstract

Background: Long-acting antiretroviral therapy (LA-ART) is currently under development and could improve outcomes for human immunodeficiency virus (HIV)-infected individuals with poor daily ART adherence.

Methods: We used a computer simulation model to evaluate the cost-effectiveness of 3 LA-ART strategies vs daily oral ART for all: (1) LA-ART for patients with multiple ART failures; (2) second-line LA-ART for those failing first-line therapy; and (3) first-line LA-ART for ART-naive patients. We calculated the maximum annual cost of LA-ART at which each strategy would be cost-effective at a willingness to pay of $100 000 per quality-adjusted life-year. We assumed HIV RNA suppression on daily ART ranged from 0% to 91% depending on adherence, vs 91% suppression on LA-ART regardless of daily ART adherence. In sensitivity analyses, we varied adherence, efficacy of LA-ART and daily ART, and loss to follow-up.

Results: Relative to daily ART, LA-ART increased overall life expectancy by 0.15-0.24 years, and by 0.51-0.89 years among poorly adherent patients, depending on the LA-ART strategy. LA-ART after multiple failures became cost-effective at an annual drug cost of $48 000; in sensitivity analysis, this threshold varied from $40 000-$70 000. Second-line LA-ART and first-line LA-ART became cost-effective at an annual drug cost of $26 000-$31 000 and $24 000-$27 000, vs $28 000 and $25 000 for current second-line and first-line regimens.

Conclusions: LA-ART could improve survival of HIV patients, especially those with poor daily ART adherence. At an annual cost of $40 000-$70 000, LA-ART will offer good value for patients with multiple prior failures. To be a viable option for first- or second-line therapy, however, its cost must approach that of currently available regimens.

Keywords: HIV/AIDS; cost-effectiveness; long-acting antiretroviral therapy; modeling.

Figure 1.

Sensitivity analysis on yearly cost at which long-acting antiretroviral therapy (LA-ART) becomes cost-effective. Horizontal bars indicate the range of threshold costs at which each LA-ART strategy reaches an incremental cost-effectiveness ratio (ICER) of $100 000 per quality-adjusted life-year (QALY) when varying the model parameters shown on the vertical axis. The dotted vertical line in each graph is drawn at the threshold cost at which each LA-ART strategy reaches an ICER of $100 000/QALY under baseline parameter values. A wider bar indicates that varying that parameter produces a greater change in the threshold cost. In parentheses after each parameter name is the base case value of that parameter; at either end of each bar are the parameter values leading to the high/low estimates of the threshold cost. When a particular alternative assumption led to the LA-ART strategy after multiple failures producing no increase in quality-adjusted life expectancy, the threshold cost was not calculated; the parameter value in question is marked NO BENEFIT. The 9 parameters producing the greatest variation in threshold cost for each strategy are shown. Threshold costs (in US dollars [USD]) are shown for LA-ART after multiple failures (A), for second-line LA-ART (B), and for first-line LA-ART (C). Research in the access of care among the homeless (REACH) indicates an adherence distribution based on the Research in Access to Care cohort of marginally housed patients with human immunodeficiency virus in San Francisco [35]. Abbreviations: ART, antiretroviral therapy; PY, person-year.

Figure 1.

Sensitivity analysis on yearly cost at which long-acting antiretroviral therapy (LA-ART) becomes cost-effective. Horizontal bars indicate the range of threshold costs at which each LA-ART strategy reaches an incremental cost-effectiveness ratio (ICER) of $100 000 per quality-adjusted life-year (QALY) when varying the model parameters shown on the vertical axis. The dotted vertical line in each graph is drawn at the threshold cost at which each LA-ART strategy reaches an ICER of $100 000/QALY under baseline parameter values. A wider bar indicates that varying that parameter produces a greater change in the threshold cost. In parentheses after each parameter name is the base case value of that parameter; at either end of each bar are the parameter values leading to the high/low estimates of the threshold cost. When a particular alternative assumption led to the LA-ART strategy after multiple failures producing no increase in quality-adjusted life expectancy, the threshold cost was not calculated; the parameter value in question is marked NO BENEFIT. The 9 parameters producing the greatest variation in threshold cost for each strategy are shown. Threshold costs (in US dollars [USD]) are shown for LA-ART after multiple failures (A), for second-line LA-ART (B), and for first-line LA-ART (C). Research in the access of care among the homeless (REACH) indicates an adherence distribution based on the Research in Access to Care cohort of marginally housed patients with human immunodeficiency virus in San Francisco [35]. Abbreviations: ART, antiretroviral therapy; PY, person-year.