. 2018 Apr 27;16(2):124–134. doi: 10.1176/appi.focus.20170044

TABLE 3.

FDA Biomarker Classification Based on Contexts of Use^a

Biomarker Type	When Biomarker Is Measured	What Biomarker Indicates
Prognostic	Prior to treatment	Indicates (estimates) the risk or likelihood that a patient who receives no further cancer-directed therapy will experience a specified clinical outcome, such as recurrence, progression, or death
Predictive	Prior to treatment	Interpret with defined criteria to identify patients who are likely to benefit from a specific treatment compared with patients who do not meet the specified criteria
Response indicator	During or after treatment	Demonstrates a pharmacological or physiological response to the treatment but does not necessarily signify patient benefit. Examples are declines in prostate-specific antigen, measures of tumor shrinkage, or pharmacodynamic changes in a parameter to show the on-target effect of a drug as proof of mechanism or to optimize dosing.
Efficiency response (surrogate)	After treatment	Provides an early and accurate prediction of both a clinical end point and the effects of the treatment on that end point

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