Initial investigation of using Norwegian health data for the purpose of external comparator arms - an example for...

Using real-world (RW) data from registries to mimic or substitute a comparator arm of clinical trials is increasingly investigated. The feasibility of using data sources for this purpose depends on the source's completeness of the wide spectrum of a disease characteristics and relevant endpoints, which could allow for proper matching of important variables.

This is a Norwegian study using data from three population-based registries, the Cancer Registry (CRN), the National Patient Registry (NPR), and the Norwegian Prescribed Drug Registry (LMR). We assessed if the registries contained the information necessary for selecting a RW cohort of patients with characteristics that mimicked the inclusion and exclusion criteria from the control arm of the phase 3 trial (KeyNote-407) on patients with stage IV, squamous NSCLC. We did this both on an aggregated - and individual data level. We also described the survival in the RW-cohorts and compared it with the survival in the control arm of the KN-407 trial.

Using aggregated data from the CRN allowed us to find the patients based on some clinically relevant inclusion criteria, but only to a limited extent could we apply the exclusion criteria of KN-407. When we used individual data from the CRN, NPR and the LMR we could create a patient cohort that shared more criteria corresponding to the eligibility criteria from KN-407, including exclusion criteria. Compared to the 11.3 months (CI 95% 9.5, 14.8) median survival in the control arm of KN-407, both RW-cohorts had a shorter median survival, 7.07 months (CI 95% 6.7, 9.5) (individual) and 8.0 months (CI 95% 5.8, 10.5) (aggregated).

Even if we demonstrated that the registries contain clinically relevant information necessary to mimic the eligibility criteria of a selected RCT, the survival is shorter for RW patients compared to their control arm counterpart in the RCT.