What is a biomarker?

The term biomarker or biological marker refers to a big selection of measures that record what is occurring in a cell or organism at a given time. Biomarkers are objective medical symptoms (versus patient-reported symptoms) used to measure the presence or progression of a disease or the results of treatment. Biomarkers could be molecular, histological, radiographic, or physiological. Examples of biomarkers include every part from blood pressure and heart rate to basic metabolic tests and X-ray results to complex histological and genetic tests of blood and other tissues. Biomarkers are measurable and don’t define how an individual feels or functions.

Although the term biomarker is comparatively latest, medical symptoms have been utilized in clinical practice for hundreds of years. Many biomarkers, comparable to heart rate, urinalysis, and blood lead levels, are widely used and well-studied. With the event of genomics and other advances in molecular biology, latest biomarker research has entered a promising era with the potential for early diagnosis and effective, personalized treatment of many diseases. In clinical trials, biomarkers can function indirect markers of disease and help determine whether a specific therapy is effectively treating the disease. The more conventional approach of using endpoints comparable to quality of life or mortality in clinical trials could make collecting sufficient data each time-consuming and expensive. Using a biomarker-based approach can shorten the time to clinical trials and speed up product development and regulatory approval.

Types of biomarkers

Types of biomarkers include:

1. Molecular – have biophysical properties that enable their measurement in biological samples (e.g. plasma, serum, cerebrospinal fluid, bronchoalveolar lavage, biopsy)
2. Radiographic – obtained from imaging studies
3. Histological – reflect biochemical or molecular changes in cells, tissues or fluids
4. Physiological – measures of processes occurring within the body

Examples:

• Blood glucose (molecular)
• Classification and staging of tumors (histological)
• Bone mineral density (radiographic)
• Blood pressure (physiological)

Biomarker Applications

Biomarkers have many useful applications in healthcare, including disease prevention and detection, determining individual disease risk, and monitoring disease. They will also be used to measure the security or toxicity of a therapeutic regimen or certain environmental exposures.

The use of established biomarkers in basic and clinical research, in addition to in clinical practice, has grow to be widespread, and their inclusion as endpoints in clinical trials is now widely accepted. Biomarkers allow for a greater understanding of disease processes and the ways during which drugs work to combat disease. This knowledge could be used to diagnose diseases earlier or prevent them before they occur. Biomarkers could be used to enhance the efficacy and safety of existing drugs and to develop latest drugs. New molecular biomarkers have the potential to personalize disease prevention and treatment, making healthcare delivery more precise, protected, and cost-effective, ultimately improving health outcomes (Raby, 2023).

Amur, S. (n.d.) Biomarker Terminology: Speaking the Same Language. US Food and Drug Administration Online Educational Materials Retrieved from https://www.fda.gov/files/BIOMARKER-TERMINOLOGY–SPEAKING-THE-SAME-LANGUAGE.pdf

BEST (Biomarkers, EndpointS, and other Tools) Resource. May 2, 2018 FDA-NIH Biomarker Working Group. Downloaded from https://www.ncbi.nlm.nih.gov/books/NBK326791/pdf/Bookshelf_NBK326791.pdf

Lou, E., Johnson M., Sima, C., Gonzalez-Espinoza, R., Fleisher, M., Kris, M., and Azzoli, C., (2014). Serum biomarkers to evaluate histology and end result in patients with metastatic lung cancer. Cancer Biomarkers, 14(4). doi: 10.3233/CBM-140399

Raby, B. (2023, September 6). Personalized medicine. Current. https://www.uptodate.com/contents/personalized-medicine