Chart assignment
Charts to read and discuss
Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.
Chart 1 of 1 · Clinical trials
How many clinical trials are in each phase?
The interactive chart needs JavaScript. The numbers are on the chart's page.
52% of the 466,000 clinical trials registered on ClinicalTrials.gov as of November 2026, some 241,000, have no phase: phases describe drug trials, and these test devices, surgery, behavior or diet. Among drug trials, Phase 2 is the most common with about 66,000. Phase 1 tests safety in a few people, Phase 2 asks whether a treatment works and at what dose, Phase 3 compares a treatment with the usual care in many, and Phase 4 follows a drug after approval.
Questions to discuss
- In one sentence of your own, what does this chart show?
- Find the biggest change or difference in the chart. What might explain it?
- Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?
Source: ClinicalTrials.gov (U.S. National Library of Medicine), counted with its API v2 (Public domain (U.S. government work); source National Library of Medicine) · Data as of Nov 4, 2026
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