Presentation (CTI)

OBJECTIVES: Reimbursement submissions to Canada’s Drug Agency (CDA) require epidemiological estimates of the disease for the indications being reviewed. These estimates are required by province, territory, and First Nations populations. Often with rare diseases, there is a dearth of real-world evidence (RWE) estimating epidemiological parameters in local jurisdictions. To examine the methods available to determine local-level epidemiological estimates of rare disease in the absence of RWE, we performed a literature review. We further reviewed reimbursement submissions to CDA in the past 10 years to identify the approaches used and the suitability of these approaches according to CDA commentary.
METHODS: The literature review on methods of soliciting epidemiological estimates for rare diseases was conducted using MEDLINE and EMBASE. The review of rare disease reimbursement submissions to CDA was conducted by searching the submissions online and reviewing the publicly available sponsor submitted evidence and CDA recommendations and reasons reports.
RESULTS: Extrapolation of international epidemiological data, adjusting for key demographic factors, where possible, emerged as the most recommended method. Incidence- or prevalence-based modeling was also frequently used, generally incorporating disease duration and mortality to derive estimates. Expert elicitation, ideally through Delphi panels, was also cited as a valuable method for determining or refining estimates. Sensitivity analyses were consistently recommended to address uncertainty. In our review of past CDA submissions, extrapolation of international epidemiological data appeared to be the most common approach utilized, with little push-back noted from CDA reviewers. Incidence or prevalence-based modelling was less common, but generally acceptable to CDA. Expert elicitation alone was highly criticized but was recommended to validate estimates.
CONCLUSIONS: In the absence of local real-world data, reimbursement submissions to CDA for rare diseases predominantly rely on the extrapolation of international epidemiological data adjusted for demographic differences. This approach is generally well-received by CDA reviewers.