Reference
Glossary
The terms this site's evidence grades are built from, defined the way the methodology uses them.
PDUFA dateThe FDA's target date for deciding a drug application, set under the Prescription Drug User Fee Act.Primary endpointThe single pre-specified outcome a trial is designed and statistically powered to test.Surrogate endpointA substitute measurement, usually a lab or imaging marker, standing in for how a patient actually feels, functions or survives.Hard endpointA clinical event, symptom or function outcome, or a regulator-accepted disease-defining measure, as this site's rubric defines it.Randomized controlled trial (RCT)A trial that assigns participants to treatment or control by chance, so the groups differ only by the treatment.Placebo-controlledA trial design in which the comparison arm receives an inactive treatment that looks identical to the real one.Double-blindNeither the participants nor the investigators know who is receiving which treatment.Open-labelA trial in which participants and investigators both know which treatment is being given.Single-arm studyA trial where every participant receives the study drug and there is no concurrent comparison group.Clinical trial phasesThe staged sequence of human testing: phase 1 (safety and dose), phase 2 (proof of concept), phase 3 (confirmation), phase 4 (post-marketing).Non-inferiority trialA trial designed to show a drug is not meaningfully worse than an existing treatment, within a pre-specified margin.Statistical significanceA pre-specified statistical threshold showing a result is unlikely to be chance alone; necessary for a confirmatory claim, not sufficient for a meaningful one.Effect sizeHow large the treatment effect actually was: the difference between arms, not just whether a difference existed.Evidence gradeThis site's design-quality verdict on a trial: strong, moderate or weak, shown as Reliable, Partial or Weak signal.Primary completion dateThe registry's estimated date for the final data collection on a trial's primary endpoint.ReadoutThe moment a trial's results become known, typically via a sponsor announcement after the primary data are collected and analyzed.NCT numberA trial's permanent identifier on ClinicalTrials.gov: the letters NCT followed by eight digits.INN (international nonproprietary name)A drug's global generic name, assigned by the WHO; the same molecule keeps one INN across every brand and market.BiosimilarA biologic approved as highly similar to an already-licensed reference biologic, with no clinically meaningful differences.Mechanism of actionHow a drug produces its effect: the target it acts on and what it does to that target.EASI-75A responder threshold in atopic dermatitis trials: at least a 75 percent improvement in the Eczema Area and Severity Index from baseline.