PALIVIZUMAB FOR USE IN INFANTS WITH CYSTIC FIBROSIS: EFFECTIVENESS AND COST-EFFECTIVENESS

Purpose: With an incidence of approximately 1 in 3,600 live births and a prevalence of 12 per 100,000 population, cystic fibrosis (CF) is the most common fatal genetic disease affecting Canadian children and young adults. Children with CF are at higher risk of severe respiratory syncytial virus (RSV) infection, which may contribute to deterioration in lung function. Palivizumab (PMB) effectively prevents RSV hospitalizations; however, at approximately $10,000 per patient per RSV season, the high cost of PMB limits its widespread use. We assess the effectiveness and cost-effectiveness of PMB prophylaxis in CF children <2 years old.

Method: A Markov cohort model of CF disease and infant RSV infections was developed based on data from the literature. Infants <2 two years old were treated with monthly PMB injections over the five-month RSV season. We defined two patient populations: all infants with CF and those infants with CF who are at high risk of RSV (having multiple siblings, born in late fall/early winter months, daycare attendance). Lifetime health outcomes, life expectancy, quality-adjusted life years (QALYs) and costs, discounted at 5%, were estimated from the Canadian healthcare payer’s perspective. Findings are summarized as incremental cost-effectiveness ratios (ICERs) and budget impact. Parameter uncertainty was assessed through deterministic sensitivity analysis. 

Result: The model was found to be a very good representation of the true population dynamics of CF in Canada. For the high-risk infants, the estimated discounted life expectancy per child was 16.29 and 16.16 for the PMB and no PMB groups respectively (16.12 and 16.09 for all CF infants). In terms of QALYs, this translated to 14.92 and 14.81 discounted QALYs for the PMB and no PMB groups, respectively (14.99 and 14.96 for all CF infants). Implementation of a hypothetical RSV prophylaxis program resulted in ICERs of $652,560 (for all CF infants) and $157,3312 (for high-risk CF infants) per QALY gained and an annual budget impact of $1,400,000 (for all CF infants) and $285,000 (for high-risk CF infants). The analysis was highly sensitive to the probability of severe RSV, the degree of lung deterioration following infection, and the cost of PMB.

Conclusion: While not considered cost-effective by commonly used thresholds, PMB prophylaxis may be considered for select CF infants given the potential long-term health benefits and relatively small budget impact.