What is clinically significant endpoint?

A clinically significant endpoint is an outcome or event in a clinical trial that provides a direct measure of the benefit or harm of a treatment or intervention for a patient. It reflects changes in health status that matter to patients, clinicians, and regulators, such as improvements in survival, symptom relief, or quality of life. These endpoints are often used by regulatory bodies like the FDA or EMA to evaluate whether a new treatment should be approved.

Clinically significant endpoints can be:

1. Overall survival (OS): The time from the start of treatment until death from any cause.
2. Progression-free survival (PFS): The time during which the patient lives without the disease getting worse.
3. Response rate (RR): The proportion of patients whose disease shrinks or disappears after treatment.
4. Quality of life (QoL): Measures that assess the impact of a treatment on a patient’s well-being, both physically and emotionally.

These endpoints are distinguished from surrogate endpoints, which are indirect measures (such as lab results or biomarkers) that may suggest a treatment effect but do not directly measure clinical benefit.