How to search for clinical trials by phase
Many clinical trials, though not all, are classified into phases (table taken from Wikipedia):
| Phase | Goal |
| Preclinical | Testing of drug in non-human subjects, to gather efficacy, toxicity and pharmacokinetic information. |
| Phase 0 | Pharmacokinetics; particularly, oral bioavailability and half-life of the drug. |
| Phase 1 | Testing of drug on healthy volunteers for safety; involves testing multiple doses (dose-ranging). |
| Phase 2 | Testing of drug on patients to assess efficacy and side effects. |
| Phase 3 | Testing of drug on patients to assess efficacy, effectiveness and safety. |
| Phase 4 | Post marketing surveillance – watching drug use in public |
In its Clinical Trials data set, Mergeflow also has this information available. You can search for clinical trials classified into a certain phase like this:
phase1*[project]
This would search for clinical trials in Phase 1. Simply combine this search by AND with the topic(s) in which you are interested. For example, the following query shows you Phase 2 clinical trials that involve "reactive oxygen species":
"reactive oxygen species" AND phase2*[project]
Suggested further reading: How to get better search results for tech discovery