Clinical Trials

Clinical Trials [5] – Clinical trials are used to test and evaluate new cancer treatment options. Testing and evaluation is accomplished via sequential steps called phases. Each phase has a purpose, and one phase must be completed before advancing to the next. We will focus on phase I, II, and III clinical trials, although phase 0 trials help to determine if a new drug should even be evaluated, and phase IV trials look at long term effectiveness and safety of a drug once it has been in use.

  • Phase I – Phase I trials involve a small number of people i.e. 15 to 30. The key function of this phase is to
    • Identify a safe dose of the drug
    • Determine the route of administration for the new drug
    • Observe how the treatment impacts the body and attacks the cancer
  • Phase II – Once phase I is completed then the researcher moves to phase II, this has a larger number of persons participating in the trial but less than 100 persons. During this phase the researcher identifies
    • If the new treatment has some type of effect on the identified cancer
    • Determine the mechanism by which the drug fights the cancer
    • How the new treatment affects the body
  • Phase III – Once it is determined that the drug has an effect on the cancer, and the side effects, then the treatment is compared to the current treatment. This uses a larger population greater than 100 and up to the thousands.
  • FDA Approval [6], [7]

    Prior to the FDA approving a new drug for use, there are a number of steps that must be taken, prior to the clinical trial phases, then the clinical trials follow. The person sponsoring the new drug must accomplish these tasks

    • The FDA must be shown what the sponsor did in preclinical animal testing, the results, and the plan for humans
    • An Investigational New Drug Application (IND) must be submitted and is reviewed by the FDA and an Institutional Review Board (IRB). The IRB must approve the phase I clinical trial prior to implementation
    • The Phase I trial is generally conducted on healthy individuals and identifies how the drug is metabolized and excreted
    • If no unacceptable toxicity is revealed in the Phase I trial, then Phase II trials is allowed to commence. Safety, effectiveness, and side effects are evaluated. Effectiveness must be demonstrated for the drug to proceed to Phase III
    • The FDA and the sponsor agree on how the Phase III clinical trials will be conducted
    • Once the FDA approves a drug for marketing, the sponsor and FDA agree on required post market and commitment studies, with prior additional information about the use, safety, and efficacy of the drug
    • The sponsor then completes the formal step of a New Drug Application – requesting approval
    • The FDA then determines whether the application would be reviewed. Application may be denied if not all required information is provided. If accepted for filing an FDA review team is assigned to evaluate the research data for safety and effectiveness
    • Information that will go on the labeling is reviewed by the FDA
    • Facilities where the drug will be produced are inspected
    • FDA reviewers either approve or issue a letter of response

There are times when drugs may receive accelerated approval, this is usually done for life threatening or serious illnesses that don’t currently have an effective treatment. In this case the drug may be used before data on effectiveness is available.

Summary Clinical Trials

The three main Phases to clinical trials are

  • Phase I – identify dose, route, impact
  • Phase II – effect, mechanism of action, side effects
  • Phase III – comparison of new treatment with established treatment

Before a drug gets to the clinical trials phases it must have initial application of the FDA including approval by an IRB.

Updated: December 21, 2023