FAQs
Companion Diagnostics & Biomarker Strategy

Q15: How do we manage parallel FDA and EU submissions for a companion diagnostic?

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Parallel FDA and EU companion-diagnostic submissions can benefit from a common global evidence strategy. Both the FDA and the EU IVDR expect robust clinical and analytical evidence. However, there are significant differences between the two jurisdictions that will influence the submission package for each market.

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The FDA generally expects the CDx and corresponding therapeutic product to be reviewed and approved contemporaneously when test use is essential to the therapy’s safe and effective use. In Europe under the IVDR, the manufacturer’s performance-evaluation process must establish scientific validity, analytical performance, and, where applicable, clinical performance. 

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A global protocol built around the final intended use, specimen types, instruments, laboratory settings, and clinically relevant decision threshold can reduce unnecessary duplication. However, the FDA submission and IVDR technical documentation must each address their distinct regulatory requirements, labeling, and benefit-risk rationale.

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Another key focus is ensuring clinical evidence reflects the intended-use population for each respective region. Where biomarker prevalence, disease biology, specimen practices, or standard of care differs by region, sponsors must justify representativeness, use bridging analyses, or include geographically diverse samples. Early coordination among the therapeutic sponsor, diagnostic manufacturer, FDA, and EU Notified Body is essential to protect timelines and maintain label alignment.

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