European Medicines Agency's Priority Medicines Scheme at 2 Years: An Evaluation of Clinical Studies Supporting Eligible Drugs.

The Priority Medicines (PRIME) scheme was launched by the European Medicines Agency (EMA) in 2016 to expedite the development and approval of promising products targeting conditions with high unmet medical need. Manufacturers of PRIME drugs receive extensive regulatory advice on their trial designs. Until June 2018, the EMA granted PRIME status to 39 agents, evaluated in 138 studies (102 initiated before and 36 after PRIME eligibility). A third of the studies forming the basis of PRIME designation were randomized controlled trials, and a quarter of the studies were blinded. There was no statistically significant difference between trials initiated before and after PRIME designation in terms of randomized design and use of blinding. However, significantly more efficacy studies included a clinical end point after PRIME designation than before, and significantly fewer included surrogate measures alone. There were no statistically significant differences between the trial designs of PRIME and non-PRIME-designated products.