Preclinical efficacy in therapeutic area guidelines from the U.S. Food and Drug Administration and the European Medicines Agency: a cross-sectional study.

<bold>Background and Purpose: </bold>Therapeutic area guidelines (TAGs) published by the EMA and the FDA offer guidance in planning the launch of a trial in a certain indication. We assessed and compared the guidance on preclinical efficacy of all available TAGs from EMA and FDA.<bold>Experimental Approach: </bold>EMA and FDA websites and databases were searched for all TAGs. A mixed deductive and inductive approach was applied to analyse and cluster content for preclinical efficacy.<bold>Key Results: </bold>A total of 114 EMA and 120 FDA TAGs were identified, covering 126 indications. Our core finding is that 75% of EMA TAGs and 58% from the FDA TAGs do not offer any guidance on preclinical efficacy. TAGs varied widely on the extent, nature and detail of guidance.<bold>Conclusions and Implications: </bold>Guidance on preclinical efficacy in a consistent, comprehensive and explicit way that still allows for justified deviations is an important but neglected aspect of transparency for drug development. This transparency would help sponsors in designing preclinical studies and in negotiating more efficiently with regulators. [ABSTRACT FROM AUTHOR]