Clinical trials are the orderly process by which new medical treatments are carefully tested for safety and effectiveness before receiving final approval by the Food and Drug Administration for general use. During clinical trials, a limited number of patients are enrolled in controlled tests to determine safety, side effects and the most effective method, frequency or timing of delivery.
New medical treatments are commonly drugs, but often also include medical devices, surgical procedures, and other types of therapies such as radiation therapy. Some trials may study combinations of several types of treatments.
The Reality of Clinical Trials
It can be easy for patients to place all their hopes on some potential miracle cure that might be discovered in a clinical trial they’re part of.
The reality is that only about 15% to 20% of all drugs that enter clinical trials are ultimately approved by the FDA as safe and effective. And even those finally approved may offer only limited improvement in quality of life or a few months advantage in survival.
No patient should be discouraged from nurturing the hope that experimental treatments may extend quality of life and add to the time they have with family and friends. Ultimately, however, the greatest benefit of participating in a clinical trial is not what the participating patient gains. It’s what the patient’s participation adds to medical knowledge that will reduce the suffering and extend the quality of life for future patients.
Every patient today is benefiting from the knowledge gained from many thousands of patients who enrolled in past clinical trials. And clinical trial participants today continue paying it forward.
The Types of Clinical Trials
Clinical trials are classified by purpose.
- Prevention – finding the best ways to prevent a disease from occurring or re-occurring
- Screening – finding the best ways to detect a particular disease or condition
- Diagnosis – finding the best tests for determining if someone has a particular disease or condition
- Treatment – finding the best ways to improve quality of life and survival in patients with a particular disease or condition
- Supportive Care – finding ways to improve the comfort and quality of life for people with chronic illnesses
For the patient diagnosed with mesothelioma, only the treatment and supportive care trials are of benefit.
The Phases of Clinical Trials for Drug Treatments
Clinical trials for drug treatments are divided into stages to allow efficient testing of experimental drugs with the lowest risk to trial participants.
Phase 1: Is it Safe?
After laboratory and/or animal testing, the applicant submits a request to conduct trials with human subjects. Phase 1 trials enroll a very small number of participants (20 to 50) and focus on studying how the drug is metabolized and the how it affects the body at varying dosage levels. The goal is oriented more at gathering biological data and preliminary indications of side effects than it is on providing an effective patient treatment.
Participants accepted into Phase 1 trials for cancer drugs are often end-stage patients who have exhausted their treatment options. A very small number are initially studied for a short time while receiving the drug in very low doses. Subsequent small groups are given incrementally larger doses to better evaluate the drug’s effects. This phase of testing is usually completed within several months.
Patients in Phase 1 trials almost never receive any personal benefit from the drug because of the short duration of treatment and the low doses.
Phase 2: Does it Work?
In Phase 2 trials, the focus shifts toward studying the drug’s effectiveness in treating the disease. This study can involve up to a hundred or more patients and may take more than a year. The goals in Phase 2 are to:
- Measure how effective the drug is
- Determine the most effective dosage
- Continue to assess side effects and risks
Selection criteria for Phase 2 trial participants depend on the nature of the drug and the nature of the study. For cancer drugs, study participants will typically be those with the target disease but for whom currently available treatments have been unsuccessful. These patients may receive a therapeutic benefit from the experimental treatment.
Although it is more likely to occur in Phase 3, some phase 2 trials are randomized trials in which one group of patients receives the new medication while a “control” group receives a standard treatment.
Phase 3: Is it Better?
The objective of Phase 3 testing is to compare the new drug to the current standard treatment to determine if it offers better results or fewer side-effects. These tests can involve hundreds to thousands of patients in randomized trials. Randomized trials are double-blind when possible – meaning that neither the patient nor the doctor knows which participants are receiving the experimental drug. Placebos are never used in randomized trials when an existing treatment is available.
Patients in Phase 3 trials may or may not experience any benefit from participation. Random chance determines which treatment they receive – either the standard treatment or the experimental one. Plus, until the study is completed, no one knows which is better.
If the results of the Phase 3 study show the new treatment is even marginally better than others that are available, the study’s sponsor can apply to the FDA for approval of the new drug.
Phase 4: What More Should We Know?
After a drug has been approved by the FDA, further Phase 4 clinical trials may be conducted to answer additional questions.
- How much more effective (or cost-effective) is the new drug compared to other competing treatments?
- What other conditions is the drug effective in treating?
- What are the drug’s long-term effects (positive or negative)?
These studies may be conducted over many years and many thousands of patients. Because drugs in Phase 4 trials are already available to any patient, participants are not receiving any better treatment or care than non-participants.
You must log in to post a comment.