Hemodynamic surrogate end-points in phase I studies?

Clinical pharmacology studies in healthy volunteers ("human pharmacology studies") characterize the pharmacokinetic and pharmacodynamic hallmarks of pharmacological action and their interrelation in the intact effector system unconfounded by disease and comedication. They constitute a valuable basis for the subsequent explicit investigation of the clinical efficacy, safety, efficiency, and therapeutic benefit in patients, but are not a valid surrogate for them.