4. What are biomarker “validation” and “qualification”?

TECHNICAL VALIDATION addresses the question “does the test work?”:

• Can the measurement be made, anywhere in the world, in a robust, consistent and reproducible way?
• Are there ethical, financial, legal or regulatory issues that would prevent use?

QUALIFICATION addresses the question: “what does the test result mean”?

• It is a ‘graded, fit-for-purpose evidentiary process linking a biomarker with biological processes and clinical end-points, dependent on the intended application’
• The key question is: can the biomarker measurement be interpreted when it is negative?

SURROGACY addresses the question: “can the biomarker substitute for a clinical endpoint in regulatory approvals?”

Wagner JA, Williams SA, Webster CJ. Biomarkers and surrogate end points for fit-for-purpose development and regulatory evaluation of new drugs. Clin Pharm Ther 2007;81:104–7