Presented herein are techniques for clinical-based automated control of the delivery of treatment substances to at least one inner ear of a recipient of an implantable medical device. More specifically, in-vivo biomarkers are analyzed to determine a biological state/status of one or more physiological elements of the inner ear. Subsequent delivery of one or more treatment substances to the inner ear of the recipient are controlled based on the determined biological state of the one or more physiological elements of the inner ear.