Cabotegravir and Rilpivirine Long-Acting Antiretroviral Therapy Administered Every 2 Months is Cost-Effective for the Treatment of HIV-1 in Spain

IntroductionCurrent antiretroviral therapies (ARTs) have improved outcomes for people living with HIV. However, the requirement to adhere to lifelong daily oral dosing may be challenging for some people living with HIV, leading to suboptimal adherence and therefore reduced treatment effectiveness. Treatment with long-acting (LA) ART may improve adherence and health-related quality of life. The objective of this study was to evaluate the cost-effectiveness of cabotegravir + rilpivirine (CAB+RPV) LA administered every 2 months (Q2M) compared with current ART administered as daily oral single-tablet regimens (STRs) from a Spanish National Healthcare System perspective.MethodsA hybrid decision-tree and Markov state-transition model was used with pooled data from three phase III/IIIb trials (FLAIR, ATLAS, and ATLAS-2M) over a lifetime horizon, with health states defined by viral load and CD4(+) cell count. Direct costs (in euro) were taken from Spanish public sources from 2021 and several deterministic and probabilistic analyses were carried out. An annual 3% discount rate was applied to both costs and utilities.ResultsOver the lifetime horizon, CAB+RPV LA Q2M was associated with an additional 0.27 quality-adjusted life years (QALYs) and slightly greater lifetime costs (euro4003) versus daily oral ART, leading to an incremental cost-effectiveness ratio of euro15,003/QALY, below the commonly accepted euro30,000/QALY willingness-to-pay threshold in Spain. All scenario analyses showed consistent results, and the probabilistic sensitivity analysis showed cost-effectiveness compared with daily oral STRs in 62.4% of simulations, being dominant in 0.3%.ConclusionFrom the Spanish National Health System perspective, CAB+RPV LA Q2M is a cost-effective alternative compared with the current options of daily oral STR regimens for HIV treatment. Plain Language SummaryOver the past decades, treatments for HIV infection have improved outcomes for people living with HIV. However, most of the treatments available consist of daily oral administration, which may present challenges for some people. These challenges may lead to a less optimal intake of the medicines and, therefore, to a potential reduction of treatment effectiveness. A new long-acting treatment alternative for HIV with two drugs is now available: cabotegravir + rilpivirine long-acting is the first injectable treatment administered in the muscle every 2 months by a healthcare professional. Long-acting injectables may improve treatment administration and health-related quality of life of people living with HIV. This study estimated the cost-effectiveness of cabotegravir + rilpivirine long-acting in Spain compared with daily oral single-tablet treatment for HIV. An economic model using clinical data and Spanish inputs was used to estimate cost-effectiveness and health outcomes over a lifetime. Cabotegravir + rilpivirine long-acting compared with daily oral single-tablet treatment showed an increase in health-related quality of life, leading to a cost-effectiveness ratio of euro15,003, below the Spanish willingness-to-pay threshold of euro30,000. All different scenarios tested showed consistent results, with cabotegravir + rilpivirine long-acting being cost-effective in 62.4% of the simulations and less costly and more effective in 0.3%. This study demonstrated that, in Spain, cabotegravir + rilpivirine long-acting administered every 2 months is a cost-effective alternative to the current daily oral single-tablet treatment options for HIV.