pharmacodynamic biomarker
Also written as: PD biomarker — pharmacodynamic biomarker
A measurable biological indicator that demonstrates a drug's effect on its target or downstream pathways, used to monitor treatment activity in precision oncology.
Full Definition
Pharmacodynamic biomarkers are measurable biological parameters that indicate whether a therapeutic intervention is engaging its intended target and producing the expected biological effect. In precision oncology, these biomarkers help clinicians determine if a targeted therapy is working at the molecular level, even before clinical response is apparent. Examples include changes in phosphorylated proteins after kinase inhibitor treatment, or circulating tumor cell counts following targeted therapy. Unlike predictive biomarkers that identify likely responders, pharmacodynamic biomarkers monitor ongoing treatment effects. They are particularly valuable for dose optimization, early detection of resistance, and confirming target engagement in clinical trials.
Usage
Usage note: Distinguish clearly from predictive and prognostic biomarkers in clinical contexts.
In Context
- "Decreased phospho-mTOR levels served as a pharmacodynamic biomarker of effective PI3K pathway inhibition." — clinical trial report
- "The absence of expected pharmacodynamic biomarker changes suggested inadequate target engagement." — dose-escalation study