Living With Cancer


Clinical Trials Overview

New drugs are tested in people through clinical trials. The clinical trial process is well documented; some excellent resources are:

* The National Cancer Institute (NCI)
* National Library of Medicine (NLM) ClinicalTrials.gov

Why Consider a Clinical Trial?

The data (information) from clinical trials is analyzed to answer the question: "Is this drug relatively safe and effective for treatment of a specific condition?"


Clinical Trial Entry Criteria

Clinical trials generate data (information) used by the FDA to determine if a drug should be approved. In order to reduce the number of variables in the data and allow meaningful analysis of safety and activity data, patients in the trial must be similar in profile.


Pre-clinical Studies

Before a new medicine is tested on people (which is what the "clinical" part of the phrase "clinical trial" refers to), researchers must first determine its physical and chemical properties in the lab and study its effects on laboratory animals.

Phase I Trials

Information on the new drug is submitted to the FDA (Food and Drug Administration) in an application known as an IND. IND stands for Investigational New Drug.


Phase II Trials

During Phase II testing a larger number of patients are recruited to the clinical trial. The goal of a Phase II trial is to learn whether the dose that has been found to be safe in Phase I is effective against the disease being treated. In some cases, the results are so impressive a drug can be approved on the basis of Phase II trials alone. More often, the drug moves into Phase III testing.

Phase III Trials

Phase III trials are designed to learn if the safety and effectiveness results from the Phase I and II clinical trials will be sustained when the drug is studied in a much larger population. Phase III studies enroll hundreds and sometimes thousands of patients. As an added benefit, testing the drug in a large population is more likely to reveal less common side effects and provide longer-term safety data. The Phase III trial usually compares the new drug's activity to the current treatment for a disease. In order for the new drug to get FDA approval, it only needs to demonstrate that it is not inferior to the current treatment.

Post-marketing Studies (Phase IV Trials)

If a drug company has received accelerated approval for a drug, the drug company must confirm in a Phase IV clinical trial that the early results they found — such as tumor shrinkage — actually mean that the patient lives longer than if they did not take the new drug.