Fidaxomicin as first line: What will it cost in the USA and Canada?

ImportanceRecent changes in the Infectious Diseases and Healthcare Epidemiology Societies of America (IDSA-SHEA) guidelines for managing Clostridioides difficile infections (CDI) have placed fidaxomicin as first-line treatment. ObjectiveTo estimate the net cost of first line fidaxomicin compared to vancomycin in the American and Canadian healthcare systems and to estimate the price points at which fidaxomicin would become cost saving. In Canada, net costs were from the public payer perspective. In the US, costs were from a healthcare and payer perspective. Data sourcesWe identified all randomized controlled trials comparing fidaxomicin with vancomycin through the 2021 IDSA-SHEA guideline update. Medication costs were obtained from internet prices (US) and the Quebec drug formulary (Canada). The average cost of a CDI recurrence was established through a systematic review for each country. Study selectionFor fidaxomicin efficacy, we included double-blind and placebo-controlled trials. For the systematic review of recurrence costs, studies were included if they were primary research articles, had a cost-analysis of CDI, included cases of recurrent CDI, and were calculated with cost parameters from American or Canadian healthcare systems. Studies were excluded if the population was solely pediatric or hospitalized. Data extraction and SynthesisFor the efficacy meta-analysis, data was pooled using a restricted maximal likelihood random effects model. For the cost review, the mean cost across identified studies was adjusted to reflect July 2022 dollars. Main Outcomes and MeasuresThe primary outcome of the meta-analysis was CDI recurrence at Day 40. The primary outcome of the systematic review was the average cost of a CDI recurrence in the American and Canadian healthcare systems. The objective was to estimate the net cost per recurrence prevented and the price point below which fidaxomicin would be cost saving to either the public payer (Canada) or the insurer (US). ResultsThe estimated mean system cost of a CDI recurrence was $15147USD and $8806CAD, respectively. At current drug pricing, to prevent one recurrence by using first line fidaxomicin over vancomycin would cost $43904USD (95%CI $35123-$65856) and $13,760CAD (95%CI $11,008-$20,640), respectively. The likelihood of fidaxomicin offering cost savings varies by country, with a 95% probability of fidaxomicin being cost saving if priced below $1180USD or $860CAD respectively. Conclusions and RelevanceAn increased drug expenditure on fidaxomicin will not be offset through recurrence prevention unless the fidaxomicin price is negotiated.