COST-EFFECTIVENESS OF BEZLOTOXUMAB+STANDARD OF CARE (SOC) VERSUS PLACEBO+SOC FOR THE PREVENTION OF RECURRENT CLOSTRIDIUM DIFFICILE INFECTION IN THE UNITED STATES
Clostridium difficile infection (CDI), a form of infectious diarrhea that can recur repeatedly after treatment, is associated with considerable morbidity, mortality and healthcare resource utilization. There were 453,000 new CDI episodes resulting in 29,000 deaths in 2011 in the U.S. Bezlotoxumab is a novel antitoxin agent that, when used in conjunction with SoC antibiotic therapy, prevents recurrent CDI (rCDI), leading to sustained clinical response. The purpose of this research is to model and evaluate the cost-effectiveness of Bezlotoxumab+SoC compared with placebo+SoC patients with CDI in the U.S.
We developed a computer-based Markov health state transition model to simulate the natural history of CDI (Figure 1). In the model, we followed patients with CDI from infection until death and evaluated the costs and effectiveness of bezlotoxumab+SoC compared with Placebo+SoC using a third-party payer perspective. To evaluate cost-effectiveness in different patient population, we conducted our analysis for the entire clinical trial population (subgroup 1), and for CDI patients at higher risk of rCDI—age 65 years and above and having a history of CDI (subgroup 2). Recurrence rates after infusion for bezlotoxumab and placebo were taken directly from the pooled MODIFY I & II phase III clinical trials' efficacy data. Other transition probabilities and costs of rCDI were obtained from the literature. We projected rCDI averted, discounted age-weighted quality-adjusted life years (QALYs), and threshold prices at which Bezlotoxumab would be cost-effective at the $100,000/QALY threshold.
The model predicted that treating patients with
bezlotoxumab+SoC will reduce the combined incidence of first, second, and third
CDI recurrences after infusion by 16.4% and 39.4% in subgroup 1 and subgroup 2,
respectively. This resulted in 0.16 and 0.28 incremental discounted
age-weighted QALYs gained per-patient for subgroup 1 and subgroup 2,
respectively. The threshold price at which bezlotoxumab is cost-effective at
the $100,000/QALY threshold is $17,188 and $30,118 for subgroup 1 and subgroup
2, respectively. Key influential parameters include CDI-specific mortality,
cost of a rCDI episode, and underlying recurrence rate.
Based on the Markov model, bezlotoxumab has the potential to reduce the disease burden associated with CDI in a cost-effective manner, by reducing the incidence of rCDI.
Figure 1: Natural History of CDI