1492 - Targeted Substitution of Omadacycline in Place of Standard of Care for CABP Treatment is Associated with a Risk Reduction of Clostridioides difficile Infection and Financial Cost Savings in the Acute Care Setting

Background: Real-world evidence studies indicate that around 3% of hospitalized patients with community-acquired pneumonia (CAP) develop Clostridioides difficile infection (CDI; Chalmers et al, J Infect 2016;73:45–53). Factors associated with increased CDI risk include Davis risk score (DRS) ≥ 6, and treatment with high-risk antibiotics such as fluroquinolones (FQ) and ceftriaxone (CTX). Omadacycline (OMC) is indicated for the treatment of community-acquired bacterial pneumonia (CABP) and has demonstrated a low propensity to induce CDI in preclinical and clinical studies. In the phase 3 OPTIC study, 2% of CABP patients who received moxifloxacin (MOX) developed CDI vs 0% for OMC (Stets et al, N Engl J Med 2019;380:517–27); 14% of MOX patients with DRS ≥ 6 developed CDI vs 0% in the OMC group (Table 1; Figure 1). We assessed the economic impact of substituting current CABP treatment (FQ and CTX) with OMC for hospitalized CABP patients with DRS ≥ 6.Table 1
Figure 1


Methods: A deterministic healthcare-decision analytic model was performed. Only excess costs associated with each treatment were considered. Base-case model inputs were: yearly CAP admission in US, prevalence of CAP patients with DRS ≥ 6, CDI risk for CAP patients with DRS ≥ 6 with current CABP treatments, CDI costs (initial and recurrent), and OMC cost (Table 2). Efficacy and safety of treatments were assumed to be equal. CDI risk of 0% was assumed for OMC. Costs are reported as USD.Table 2


Results: For patients with CABP, total CDI costs were $738M, with first-episode costs of $489M plus recurrence costs of $249M. The cost of 5 days (mean hospital length of stay for CABP) of OMC was $207M. Use of OMC for the estimated 100,000 CABP patients with DRS ≥ 6 would result in a potential cost saving of up to $531M for this patient population, assuming CDI risk of 0% with OMC. As CDI is a risk from any antibiotic use, cost savings can be achieved when OMC is used in place of high-risk antibiotics patients when CDI risk rates exceed 3.9%.

Conclusion: Our findings suggest prioritizing use of omadacycline over current CABP treatments in hospitalized CABP with a DRS ≥ 6 may substantially reduce attributable CDI costs. These results can serve as a basis for stewardship interventions to reduce hospital CDI rates and associated costs.