BACKGROUND: Preventing recurrences is critical in recurrent CDI (rCDI) management because it eliminates/mitigates debilitating and life-threatening complications and reduces associated clinical, humanistic, and economic burden. Fecal microbiota spores, live-brpk (VOWST™; formerly SER-109 and hereafter referred to as VOS) and fecal microbiota, live-jslm (REBYOTA™; formerly RBX2660 and referred to as RBL) are microbiome therapies recently FDA-approved for prevention of rCDI following antibacterial treatment of rCDI in adults.
OBJECTIVE: To model clinical/economic costs of treating patients with rCDI with VOS vs RBL for prevention of recurrences in the US.
METHODS: An Excel-based budget impact model was used to calculate number of recurrences and total costs in patients with rCDI treated with VOS vs RBL. Epidemiologic data, underlying rCDI risks, and treatment/recurrence costs in the model were obtained from published literature. Recurrence risk reductions were obtained from Phase 3 pivotal, randomized, placebo-controlled trials: ECOSPOR III (VOS) and PUNCH CD3 (RBL). The model estimated outcomes for a hypothetical cohort of 100 patients with rCDI over a 1-year follow-up period. All recurrences (first and subsequent) were assumed to be treated either with RBL or with VOS following antibiotic treatment for rCDI. Costs included wholesaler acquisition cost price, administration cost, and cost of recurrence. Cost outcomes (pharmaceutical/medical) were reported undiscounted in 2023 US dollars.
RESULTS: In this analysis, 100 patients had 43 subsequent recurrences accounting for $2.020 million in total costs when treated with RBL, vs 15 recurrences accounting for $0.826 million when treated with VOS. Total drug costs (including RBL administration costs) for treating first and subsequent CDI recurrences were $1.375 million and $2.060 million for RBL and VOS, respectively. Differences in treatment costs associated with VOS vs RBL were fully offset by reductions in medical/antibacterial costs due to VOS preventing 28 additional recurrences vs RBL over 1 year. This resulted in an overall cost savings of VOS vs RBL of $357,882. Treating rCDI at first recurrence with VOS (vs RBL) resulted in per-patient incremental cost of $7068 in microbiome therapy during the study period. However, per-patient total cost savings (-$3579) will be realized after 1 year due to substantial medical cost savings from avoiding subsequent CDI recurrences.
CONCLUSIONS: This model, which utilized clinical outcomes data from Phase 3 trials, predicted a higher number of recurrences with RBL vs VOS. VOS is a cost-saving treatment vs RBL, mainly due to a higher number of CDI recurrences prevented and reduction in recurrence costs with VOS. VOS treatment provides opportunities to improve clinical outcomes in rCDI and reduce healthcare costs associated with recurrence.
