In order to consider biomarkers during drug development processes, they must have been approved directly by the US Food and Drug Administration (FDA) staff or must undergone the FDA's Biomarker Qualification Program (BQP).
The the FDA defines a the qualification of a biomarker as “a conclusion that within the stated context of use, a biomarker can be relied upon to have a specific interpretation and application in drug development and regulatory review”.
According to this institution “a qualified biomarker can be used in multiple drug development program without the need for CDER to reconfirm the suitability of the biomarker’s qualified context of use”.
The 21st Century Cures Act signed into law on December 2016 including the section Qualification of Drug Development tools, formally establishing a multistage process for biomarker qualification:
1 - Letter of Intent (LOI) - Initiates the qualification process of a biomarker for a proposed context of use (COU) in drug development.
2 - Qualification Plan (QP) - Defines the intended development to generate the necessary supportive data to qualify the biomarker for the proposed COU.
3 - Full Qualification Package (FQP) - Contains all accumulated data to support the qualification of the biomarker for the proposed COU.
The FDA is responsible of accepting qualification submission ant any if the three stages, based on different factors such as the scientific merit of the submission.
If it is accepted there is a fourth stage, the Qualification Reccomendation by the FDA, which, Contains FDA’s determination on whether the biomarker is qualified for the proposed COU based on a comprehensive review of the FQP.
Industry perspectives on biomarker qualification by G Lavezzari and AW Womack - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5065241/