About 10,000 compounds will be tested for an individual drug to eventually reach the market. It might be helpful recapitulating previous failures and identifying the main factors of the disappointments. In this review, the author(s) detailed the 7 cardiovascular compounds discontinued after reaching animal studies or Phase I-III clinical trials during 2015. Meanwhile, the reasons for these discontinuations were reported. Among these drugs, most discontinuations (6 drugs) were attributed to lack of efficacy. In general, failures due to lack of efficacy and safety demonstrate the need for the development of more predictive animal models. However, recent related studies showed that the absence of toxicity in animals provided little or virtually no evidential weight that adverse drug reactions would also be absent in humans. In this case, microdosing and collaborating more closely with biotech companies may be the better choices to improve the success ratio. Future researches may benefit from the seven developments and investigators conducting similar studies may learn from these failures.