Table 1.

Potential benefits of response biomarkers

Benefits to the Patient	Effects on Clinical Practice	Socioeconomic Benefits	Benefits to Industry
Minimal exposure to potentially toxic drugs that are unbeneficial.	Can tailor therapy for patients by development of a biomarker that reflects chemosensitivity and resistance.	Payors (including insurance companies and patients) will pay much less for ineffective drugs.	Clinical trial design would be revolutionized: a) Will provide a new trial endpoint for phase I trials, enabling identification of appropriate doses and patient populations with less harm to trial participants. b) Phase II trials can be performed more quickly, using the biomarker as a surrogate marker for benefit. c) Would greatly facilitate a “go-no go” phase II-III adaptive designs106.
Reduced cumulative toxicities will improve quality of life.	The current practice is to administer a drug until toxicities or disease progression occur. A response biomarker may inform on early chemoresistance. This has the following benefits: a) Inappropriate dose escalations can be avoided. b) Inappropriately prolonged treatments can be avoided. c) Possibility of rotating to a new potentially effective drug regime before progression and clinical deterioration occur.	Patients whose quality of life is preserved and whose disease is controlled with less toxicity will be more likely to be able to resume normal work activities.	Subpopulations that will benefit from drugs will be more easily identified.
Preservation of performance status will facilitate administration of later lines of therapy.	May enable dose titration: lowest effective dose for an individual could be administered.	Novel drug development will be less expensive and more efficient. This may translate to development of more, less costly drugs.	It may become cost effective to screen agents for use in rare cancers.
A response biomarker may expand the therapeutic armamentarium available for patients: low cost trials of drugs on individuals.	A serum biomarker of response would enhance treatment of patients with malignant conditions that are difficult to gauge radiologically e.g. peritoneal disease, bile duct cancer and esophagogastric cancer.		There may be less need for predictive biomarkers, which are specific to each drug, and which take years to develop and validate.