Genesis of Clinical Trial Failure: A Review

Abstract

Clinical Trials are often labelled as failure or negative when the anticipated results are not observed. The negative results can be due to multiple factors such as primary and secondary endpoints not being met higher incidence of adverse reactions, and sluggish recruitment of trial subjects due to stringent inclusion and exclusion criteria, higher dropout rates due to changed biochemical parameters such as raised liver or hepatic enzymes. Trial Failures are reported globally but within developing countries, the reports are meagre. Inclusion in trials imposes a financial burden on patients and hence dropout rates proportionately increase. Recruitment of patients is often better in open trials as compared to blind studies as drug awareness imposes better confidence in the recruited subjects. The oncology trials that use biomarkers in patient selection have higher overall success probabilities than trials without biomarkers. Complexities in drug development and the inherent uncertainties in medical research also play an important role in a high rate of clinical trial failures.