RP-64477 is primarily used in research settings as a potent and selective antagonist of the 5-HT2B receptor, making it a valuable tool for studying serotonin receptor subtypes and their roles in physiological and pathological processes. It has been investigated for its potential in mitigating cardiac fibrosis, a condition linked to chronic activation of the 5-HT2B receptor, particularly in cases associated with certain drugs or diseases. Due to its high selectivity, RP-64477 helps researchers dissect the specific contributions of 5-HT2B signaling without significant off-target effects on related serotonin receptors. It is also employed in neuroscience and cardiovascular research to explore the links between serotonergic signaling and heart valve integrity, as well as in the development of safer pharmacological agents that avoid 5-HT2B-mediated cardiotoxicity. Its application remains largely confined to preclinical studies, where it aids in validating 5-HT2B as a therapeutic target.