Biomarkers Flashcards
Biomarker
A characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention
Eg. Bp and Hb levels
Usefule biomarker factors
-Informs risk/benefict ratio when there is a decision to be made
-Does so in a better/faster/earlier/cheaper way than existing approaches
-Generally applicable: sample and technology must be availible/accessible
% ineffective SSRI
8%
% ineffective Asthma
40%
% ineffective DIabetes
43%
%Rheumatoid arthritis
50%
% Alzeimer’s disease
70%
% Cancer
75%
Questions that can be addressed by biomarkers
-Have I got cancer: Early detection
-What type of cancer have I got and what is my prognosis: Test (ER-, Pr-, Her2-)
-What treatment is best for me: (tamoxifen)
-Is my treatment working
-Will my cancer come back: Recurrence and possibility of other cancer
Key advantages of biomarkers
-Early detection of disease
-Drug Development
-Assay development
How can BM help save more lives from cancer
Most cancer diagnosied when 1-4cm in size
-By this time it may have metasized
-To reduce cancer-specifc mortality, we need effective biomarkers for:
-Risk Assesment
-Early detection
-Therapy
Factors for diagnostic kit
-Easy to use in clinical setting
-Cost effective
-Proven results
-Samples: Blood, serum, urine, etc. (prostagin antigen (PCA3))
HER2 biomarker disease + Drug
Breast cancer
Herceptin
Estrogen and progesterone receptors
Breast acncer
Tamoxifen
HER2 acronym
Human Epidermal growth factor Receptor 2
Major functions of biomarkers (different types of biomarkers)
Is the therapy hitting the target: Pharmacodynaimc (PD) markers
Is there a response to the therapy: Efficacy markers
Will there be a response to the therapy: Patient stratification and patient selection biomarkers
Is there or will there be toxicity for the therapy: Toxicity biomarkers
Why are new biomarkers needed
-False positives
-Cannot differentiate between stages of disease
-Not universal (CA 125 is expressed in 50-60% of patients during early stages of ovarian cancer)
Bottle-neck in biomarker development
Quality samples
validation
Only 100 BM used in clinic out of 150,000
Why is discovery of useful BM difficult
-Biology: most of genetic changes from malignant tumors are unknown
-Need for infrastructural support
-Need for collaboration among stakeholders: Basic scientists, Clinicians, Public Health proffesionals, Informaticians and Bionformaticians, advocates, Funding organistations, Regulatory authorities
What is needed to discover and use more biomarkers
-Collaborations between Academic institutions and industries (both pharma and diagnostic)
-Input from regulation experts
-Repositories of quality samples
-More funds to promote biomarker research at an academic level
Benefits of biomarkers for all stakeholders
-Patients: Increased effectiveness of therapies
-Doctors: Increased safety in treatment decisions
-Healthcare providers: better outcomes for less cost
-Pharma companies: Regulatory approval and competitive advantage
-Diagnostic companies: New market opportunities
