Phase 0 Trial

Drug takes years to be available in the market for general use. It is an expensive, time consuming and full of uncertainty process. It demands billion of dollars and a good time of 10-15 years to develop a single therapeutic product. Hence, it is important to study the feasibility of drug development process before starting the full scale clinical trial process. Phase 0 studies (also known as exploratory investigational new drug studies) helps in identifying the possible and workable therapeutic product by investing very less resources.


Need of Phase 0 Trial

The need of phase 0 entered into the picture in response to decreasing rate of success of drug development process. The high cost to produce a single worthy compound and the ethical concern related to exposure of human beings to novel products highlighted the requirement of phase 0 (i.e., micro dosing) trial. Phase 0 trial is also known as “Pre-phase 1 trial” or "proof-of-concept trial”.


Endpoints of Phase 0 trial


Features of Phase 0 trial


  • A kind of interim step between pre-clinical research and phase I clinical research

  • Study subjects less in number (usually 10-12)

  • Normally healthy volunteers are taken for the investigation

  • Low dose of investigational drug is used for a minimal duration to minimize the chances of toxicity


Objective of Phase 0 trial


The prime objective of Phase 0 is to check if the investigational product act in human body as it should. Phase 0 also focuses on collecting other relevant information such as basic pharmacokinetic and pharmacodynamic data. This phase do not concentrate on studying the therapeutic effect of the novel product. Phase 0 study provides information which helps in deciding whether to proceed or not with the experiment of the new drug in human body which has shown positive response in animal experiment i.e., pre-clinical research.