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• Cancers at a glance
• Research highlights
• About cancer research
  • What is 'research'?
  • The scientific method
  • Different areas of research
    • Basic research
    • Translational research
    • Clinical research
      • Phase 1 trials
      • Phase 2 trials
      • Phase 3 clinical trials
      • Phase 4 clinical trials
    • Behavioural and population research
    • Psychosocial research
• Understanding 'risk'
• Our history and achievements

Phase 2 clinical trials

Phase 2 trials are carried out to see whether the drug or treatment is effective for treating cancer. Only a treatment that passes phase 1 is tested in a phase 2 trial.

Researchers test the new treatment in about 30 to 100 patients. They may all have the same type of cancer, or several different types of cancer. The optimal dose found in the phase 1 study is usually used in these trials.

Treatments can affect people in different ways. By giving the treatment to a larger group of people, the researchers also get a better idea about how safe it is.

The same treatment is often tested in many different phase 2 trials. This is so the researchers can look at the effect of the treatment in a range of cancer types.

If you want to find out even more about phase 2 clinical trials, have a look at the ‘Understanding clinical trials’ section of our CancerHelp UK website.