Objective: Respiratory syncytial virus (RSV) hospitalization rates have increased since the American Academy of Pediatrics updated guidelines in 2014 to recommend against the use of palivizumab for preterm infants 29 – 35 weeks’ gestational age (GA) without additional risk factors. A new treatment candidate, nirsevimab, is being developed to target this population. We compared the cost-effectiveness of palivizumab with standard care (no prophylaxis) in this population and estimated the cost-effective price for nirsevimab.

Methods: Using a theoretical cohort of preterm infants, a semi-Markov model was constructed to predict the RSV clinical course in the first year of life and sequelae in the subsequent four years from the healthcare and societal perspectives. Costs, utilities, and probabilities for the model were derived from a comprehensive literature review. The model calculated costs and quality adjusted life-years (QALYs) to produce an incremental net monetary benefit (iNMB) evaluated at a willingness-to-pay threshold of $150,000/QALY. Deterministic and probabilistic sensitivity analyses were performed to assess the impact of assumptions. A threshold analysis was conducted to determine the cost-effective price for nirsevimab.

Results: Palivizumab was not cost-effective vs. standard care, costing $9,575 and $9,606 more from the healthcare and societal perspectives, respectively, with 0.0019 QALYs gained per patient over 5 years, resulting in iNMB of -$9,291 and -$9,322 from each perspective, respectively. The result was robust to parameter uncertainties, and probabilistic sensitivity analysis revealed that at $150,000/QALY, standard care had a 100.0% probability of being cost-effective. The threshold analysis suggested that, from the societal perspective, nirsevimab would be cost-effective compared with standard care and palivizumab if priced below $1,932 and $11,254, respectively.

Conclusions: Palivizumab is dominated by standard care from the healthcare and societal perspectives for preterm infants 29 – 35 weeks’ GA that are otherwise healthy. Nirsevimab, if priced appropriately, may be a cost-effective alternative.