Cost-effectiveness of broadly neutralizing antibodies for infant HIV prophylaxis in settings with high HIV burdens: a simulation modeling study

Introduction

Approximately 130 000 infants acquire HIV annually despite global maternal antiretroviral therapy scale-up. We evaluated the potential clinical impact and cost-effectiveness of offering long-acting, anti-HIV broadly neutralizing antibody (bNAb) prophylaxis to infants in three distinct settings.

Methods

We simulated infants in Côte d'Ivoire, South Africa, and Zimbabwe using the Cost-Effectiveness of Preventing AIDS Complications-Pediatric (CEPAC-P) model. We modeled strategies offering a three-bNAb combination in addition to WHO-recommended standard-of-care oral prophylaxis to infants: a) with known, WHO-defined high-risk HIV exposure at birth (HR-HIVE); b) with known HIV exposure at birth (HIVE); or c) with or without known HIV exposure (ALL). Modeled infants received 1-dose, 2-doses, or Extended (every 3 months through 18 months) bNAb dosing. Base case model inputs included 70% bNAb efficacy (sensitivity analysis range: 10-100%), 3-month efficacy duration/dosing interval (1-6 months), and $20/dose cost ($5-$100/dose). Outcomes included pediatric HIV infections, life expectancy, lifetime HIV-related costs, and incremental cost-effectiveness ratios (ICERs, in US$/year-of-life-saved [YLS], assuming a ≤50% GDP per capita cost-effectiveness threshold).

Results

The base case model projects that bNAb strategies targeting HIVE and ALL infants would prevent 7-26% and 10-42% additional pediatric HIV infections, respectively, compared to standard-of-care alone, ranging by dosing approach. HIVE-Extended would be cost-effective (cost-saving compared to standard-of-care) in Côte d'Ivoire and Zimbabwe; ALL-Extended would be cost-effective in South Africa (ICER: $882/YLS). BNAb strategies targeting HR-HIVE infants would result in greater lifetime costs and smaller life expectancy gains than HIVE-Extended. Throughout most bNAb efficacies and costs evaluated in sensitivity analyses, targeting HIVE infants would be cost-effective in Côte d'Ivoire and Zimbabwe, and targeting ALL infants would be cost-effective in South Africa.

Discussion

Adding long-acting bNAbs to current standard-of-care prophylaxis would be cost-effective, assuming plausible efficacies and costs. The cost-effective target population would vary by setting, largely driven by maternal antenatal HIV prevalence and postpartum incidence.

Projections of diagnosed HIV infection in children and adolescents in New York State

Decreasing mother-to-child transmission is changing the population of children and adolescents with HIV. This project used recent epidemiological data to develop short-term projections of children and adolescents living with diagnosed HIV infection in New York State. A population simulation model was created to project prevalence of diagnosed HIV cases aged 0-19 years by age, sex, race/ethnicity and risk for years 2007-2014. Using 2006 data as the baseline population and 2001-2006 diagnosis and death data, annual diagnoses and deaths were calculated for each age/sex/race/risk category and known cases were 'aged' into the next year. The model produced annual estimates until 2014. The model predicts a decline in the number of persons aged 0-19 years living with diagnosed HIV in New York from 2810 in 2006 to 1431 in 2014, a net decrease of 49%. Living cases with paediatric risk continue to decrease. Cases aged 13-19 with non-paediatric risk increase slowly, leading to a shift in the risk composition of the population. The dominant effect seen in the model is the ageing out of perinatally infected children born before measures to prevent mother-to-child transmission were broadly implemented in the mid- to late 1990s. Changing trends in the young HIV-infected population should be considered in developing public health programmes for HIV prevention and care in New York State for the coming years.