Definition
Surrogate Endpoint is a biomarker or laboratory measurement intended to substitute for a clinical endpoint in drug trials. It’s reasonably likely to predict clinical benefit but is not itself a direct measure of how a patient feels, functions, or survives.
How Surrogate Endpoints Work
FDA accepts surrogate endpoints when direct measurement of clinical outcomes would require excessively long trials. The surrogate must have strong scientific rationale connecting it to clinical benefit.
Types of Surrogate Endpoints
| Type | Definition | Example |
|---|---|---|
| Validated | Strong evidence predicts clinical outcome | LDL cholesterol for CV events |
| Reasonably Likely | Biologic plausibility but less evidence | Tumor response rate for survival |
| Candidate | Early stage, requires validation | Novel biomarkers |
Use in Accelerated Approval
Surrogate endpoints enable accelerated approval by allowing:
- Shorter, smaller trials
- Earlier access for serious diseases
- Continued evaluation post-approval
- Faster development timelines
Why BD Teams Track Surrogate Endpoints
For business development professionals, surrogate endpoints affect development strategy:
- Deal Implication: Validated surrogates reduce development risk and timelines
- Due Diligence Focus: Assess surrogate-clinical outcome relationship strength
- Opportunity Signal: Novel surrogates create competitive advantages in development