Surrogate endpoint

Surrogate Endpoint

A Surrogate Endpoint (pronunciation: /ˈsʌrəɡət ˈɛndˌpɔɪnt/) is a term used in clinical trials to refer to a biomarker or physical sign that can be used as an indirect measure of disease progression.

Etymology

The term "surrogate" originates from the Latin word "surrogatus", meaning to substitute or replace. The term "endpoint" in this context refers to the outcome or result of a clinical trial. Thus, a surrogate endpoint is a substitute or replacement for a direct measure of how a patient feels, functions, or survives.

Definition

In clinical research, a surrogate endpoint is a biomarker or physical sign used as a substitute for a clinically meaningful endpoint. A surrogate endpoint does not measure the clinical benefit of a treatment directly, but rather predicts its effect. It is often used in clinical trials when the primary endpoint is expected to take a long time to occur.

Related Terms

Clinical trial: A research study that tests how well new medical approaches work in people.
Biomarker: A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease.
Primary endpoint: The main result that is measured at the end of a study to see if a given treatment worked.
Secondary endpoint: A result that is measured at the end of a study to evaluate additional effects of the treatment.

Usage in Clinical Trials

In clinical trials, surrogate endpoints are often used when the primary endpoint is expected to take a long time to occur. For example, in a trial studying the effects of a new drug on heart disease, the primary endpoint might be the reduction in heart attacks. However, it could take many years to observe a significant difference in heart attack rates. In this case, a surrogate endpoint, such as a reduction in cholesterol levels, could be used to predict the drug's effect on heart attack rates.