Biomarker — What It Means in Clinical Trials
Plain English Definition
A biomarker is a measurable substance or characteristic in your body that helps doctors make decisions about your treatment. In clinical trials, biomarkers might include specific proteins, gene mutations, or blood test results. Many modern trials require you to have a specific biomarker to qualify.
Why It Matters
Targeted therapies work on specific biomarkers. If a trial requires a biomarker you do not have, you will not be eligible. Ask your doctor to test for relevant biomarkers — this can open doors to more trial options.
Example
A listing might say: "Must have confirmed HER2-positive breast cancer" or "PD-L1 expression >= 50%." These are biomarker requirements.
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