For the last few decades, the contributions of different biomarkers to the field of drug discovery and development has been precious. From identification of the target to its validation to clinical application, biomarkers have an overall impact on the drug production. To understand their role, let us first explore what a biomarker is all about –

What is a biomarker?

In the medical field, a biomarker is defined as a measurable indicator used in the identification of severity and presence of a particular diseased state. It is, in fact, a substance that can be introduced into the body as a mediator for examining the functioning of the targeted organ or any other health aspect. They are mostly biological properties or any biomolecules that can be utilized in the detection and measurement in various body tissues or organs. Some common types of biomolecules used are – enzymes, molecules, specific cells, hormones, genes or gene products.

Biomarker Assays in Drug Discovery and Development –

A biomarker contributes both to the drug development and clinical assessment of the severity of a particular disease. Over time, they have become an integral part of drug development processes such as screening, disease detection, and quality optimization. Since generations, they are being used in keeping a check on the biological processes.

Importance of biomarker assay validation –

Qualification and validation of biomarker assay is essential as they are extensively used in the process of drug development. While qualification involves assessing the biomarker action, validation is a documentation process to understand the efficacy of the selected biomarker. Depending on the type of biomarker assays and their requirements, there are two essential categories of biomarkers – exploratory and valid.

Selection of a biomarker –

There are various factors to consider before shortlisting a particular biomarker for your biomarker assays –

  • In the very first step, the clinician must identify and define the end-point essential for biomarker testing.
  • Secondly, data assembly is done for establishing a correlation between the possible biomarkers, chemical exposure, and the final end-point of the study.
  • Next, the assessment of both the specificity and sensitivity of the biomarker in co-relation to their exposure and health significance is conducted.
  • Specimen consideration to be targeted for analysis.
  • Reviewing the possible analytical procedures for qualification and quantification of the biomarkers being used.
  • Development, establishment, and validation of an appropriate protocol for quality assurance and control for the biomarkers

Challenges before biomarker validation –

Validation is a process wherein you assess the analytical method selected for a particular biomarker, thereby facilitating its performance characteristics. Criteria for validating the biomarkers are as follows –

  • What is the target of action or the question for which this biomarker is being designed?
  • Degree of certainty which will define an answer to the previous question.
  • Assumptions to be made for establishing a relationship between changes in the biomarker’s behavioural pattern and the selected clinical end-points or clinical utilities.

Important points to be considered during biomarker validation –

The following points are essential for biomarker validations –

  • The requirement of the endogenous quality controls
  • The behavioural pattern of endogenous molecules
  • Verification of the properties of the endogenous molecules