Clinical study and Clinical trial

Clinical trial and clinical study are semantically related. In some cases you can use "Clinical trial" instead a noun "Clinical study".

Clinical trial noun - A rigorously controlled test of a new drug or a new invasive medical device on human subjects; in the United States it is conducted under the direction of the FDA before being made available for general clinical use.

Clinical study and clinical trial are semantically related. You can use "Clinical study" instead a noun phrase "Clinical trial".