The FDA has issued draft guidance on the use of Bayesian statistical methods in clinical trials of drugs and biological products.[1][3] This guidance helps sponsors make better use of available data, conduct more efficient trials, and bring safe and effective treatments to patients more quickly.[3] Bayesian methods combine trial data with relevant prior information to generate a new distribution for conclusions about safety and efficacy.[3][6] They can serve to determine failure or success in adaptive trials, dose selection in further trials, incorporation of data from previous studies or real-world data, and support of the trial's main conclusion.[3][4] They are particularly useful for rare or pediatric indications with smaller numbers of patients.[3] The guidance meets FDA's commitment in Prescription Drug User Fee Act (PDUFA) VII.[3] JAMA published three views on this proposal, two of which welcomed it.[user]