Overview
There's a growing trend of using real-world data from different countries when traditional randomized control trials might not be feasible. However, this raises an important question about whether real-world evidence from one country can be used for HTA decision-making in another, a concept known as “transportability”, as it has not been well established whether outcomes observed in one country will apply to another.
This research evaluates the transportability of overall survival estimates from the US to the UK for metastatic breast cancer (mBC) using nationally representative data from the Flatiron Health EHR-derived, deidentified database for the US and the National Cancer Registration and Analysis Service cancer registry for the UK. After accounting for differences in population characteristics, outcomes for patients with mBC were similar in the US and UK. This suggests that when local data is unavailable, US data can serve as a reliable alternative, as adjusted US values closely correspond with observed outcomes for UK patients.
Why this matters
When local data is unavailable or insufficient, international data can help reduce uncertainty about how well a drug or treatment is expected to perform in another country. This research validates transportability as a methodology for using data across borders, with the potential to improve standards of care, speed to access treatments, and provide more confidence in how medicines perform. Further research is needed to evaluate the transportability of real-world evidence across additional diseases and between other countries, and to explore the suitability of using other methods of adjustment.