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

Importance Recent 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. Objective To 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 sources We 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 selection For 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 Synthesis For 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 Measures The 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). Results The 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 Relevance An increased drug expenditure on fidaxomicin will not be offset through recurrence prevention unless the fidaxomicin price is negotiated. ### Competing Interest Statement EGM and TCL are principal investigators on a Canadian Institutes of Health Research Funded clinical trial looking at alternative vancomycin dosing strategies for the first episode of C. difficile. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors