What is a Clinical Trial?
- A study conducted to test if a particular medical treatment / device is safe and effective in patients.
- Most trials are for medicine, but can be for any form of treatment or medical device.
- Some trials involve testing completely new treatments, others study the safety and effectiveness of slight changes in already existing treatments, whilst others are run to determine if an existing treatment can be safely used to treat diseases other than those for which the drug was first developed.
Why are Clinical Trials so important?
- Allow doctors to understand how a new medicine works.
- Help doctors assess if the new medicine is safer and more effective than existing medicines.
- Gain an understanding of the best way to use particular treatments.
- Work towards increasing the benefits and decreasing the risks associated with effective treatments.
How are Clinical Trials conducted?
A clinical trial falls into one of four phases:
Phase One Trials:
- Involve a small number of healthy people, although in some cases, people with a disease may be enrolled.
- Any adverse effects are easier to see if the patient is healthy.
- Performed to determine the basic characteristics of the medicine eg;
- The safe range of doses.
- How the medicine should be given.
- How it interacts with the human body.
- Detecting side effects with increasing doses of the medicine.
Phase Two Trials:
- Involve a larger group of patients (no more than a few hundred).
- Address the effectiveness of the medicine/device being studied.
- Provide additional information on the safety of the medicine and the proper dosage required.
- Gather more information on the short-term risks associated with the treatment.
Phase Three Trials:
- Are much larger studies involving many hundreds, or thousands, of patients.
- Compare the effectiveness of the new treatment with already existing treatments for the same condition.
- Less common side effects may also emerge.
- If the medicine is safe and effective, it may be licensed for marketing by the Therapeutic Goods Administration (TGA) of Australia (or by similar agencies around the world, e.g. the US Food and Drug Administration, FDA).
Phase Four Trials:
- Are carried out after the medicine has been released into the market.
- Are conducted to learn more about the medicine.
- Determine the impact of the medicine in long-term use.
- May find rare, but important, side effects not detected in earlier trials.
- If these are serious, it can lead to the medicine being removed from the market.
Who runs a Clinical Trial?
- A team of people from a wide variety of backgrounds help conduct a clinical trial.
- The team is usually led by a doctor, who is known as the Principal Investigator.
- Other doctors, as well as pharmacists, nurses and scientists assist.
- The clinical trial team is responsible for assessing the health of the participants before the trial begins and monitor the participant’s health and wellbeing during and after the trial.
Who can participate in a Clinical Trial?
- For every clinical trial, there are a set of guidelines specifying who can participate in the trial.
- In order to be suitable for the study, patients must meet the inclusion criteria of the trial.
- In addition, they must not satisfy any of the exclusion criteria.
- These criteria are based on many factors, including age, medical history and any diseases that the patient currently suffers.
- They ensure that only the appropriate patients are enrolled in the trial.
- This is to minimise any study associated risks to the patient.
If you are found ineligible for a study – it is for your own safety!
Why participate in a Clinical Trial?
There are many benefits to be gained from participating in a clinical trial. For patients these include:
- Gaining access to treatments that are otherwise unavailable to the general public.
- Obtaining the treatment at no cost during the clinical trial.
- Obtaining access to medical care that is associated with the trial.
- Participating in the development of new treatments that may later aid many people.
In addition to the benefits available from participating in a clinical trial, there are also risks associated with being a participant in a study. These include:
- The new treatment being ineffective.
- Side effects that may result from the use of the new treatment.
- More frequent visits to the doctor, hospital or medical centre in order to participate in the study.
- Undergoing invasive procedures, such as blood tests.
Finally, the patient also has responsibilities e.g. committing to clinic visit schedules, or having to maintain a diary of your condition.
What is the role of the Ethics Committee?
- Clinical trials must be approved by an Ethics Committee before they can begin.
- The main purpose of the Ethics Committee is to safeguard the interests of the patients involved in the study.
- The Ethics Committee itself is governed by a set of guidelines set by the National Health and Medical Research Council (NHMRC).
- These guidelines ensure that the interests of participants are being protected.
The members of the Ethics Committee come from a wide variety of backgrounds. They include:
- Medical professionals
- Ministers of Religion
- This variety ensures that diverse viewpoints are considered when clinical trials are reviewed.
- The doctor / medical centre / hospital conducting the clinical trial must report their procedures to the Ethics Committee.
- They must also report any risks believed to be associated with the trial and any changes to the study protocol.
- If the risks involved in the trial are greater than the benefits the patients receive, then the study may be rejected, or terminated, by the Ethics Committee.
What are the responsibilities of the Sponsors and Researchers?
- All clinical trials have a Sponsor.
- The Sponsor of a clinical trial is the individual, company, research institution or organisation that funds a research study.
- The Sponsor takes responsibility for beginning and managing a clinical trial.
- Researchers on the other hand, are employed by the Sponsor and are responsible for carrying out the clinical trial.
- Both the Sponsors and the Researchers who conduct the clinical trial must ensure that:
- Regulatory and ethical guidelines that govern all clinical trials are followed.
- The Ethics Committee has given approval to conduct the clinical trial.
- The resources required to conduct the clinical trial are provided, including funding, staff and facilities.
- Appropriate methods of compensation are available should serious injury result from participation in a clinical trial.
- A Sponsor may transfer any or all of their clinical trial-related duties to a Contract Research Organisation. However, the responsibility for the quality of the clinical trial still remains with the Sponsor.
Commonly Used Research Terms
Research terms that are often used when describing a clinical trial include:
Adverse Events Undesirable side effects that may occur in a clinical trial, which may or may not be a result of taking a study medicine are known as adverse events.
Audits Throughout the duration of a clinical trial and after the trial has been completed, audits may be conducted. These routine checks are performed to ensure that the trial is conducted responsibly and ethically.
Informed Consent Participants must give fully informed voluntary written consent before they are able to take part in a study. Before enrolling in a trial, participants discuss the study with the doctor. This consent form indicates that participants are fully informed and are taking part in the study of their own free will.
Placebo A placebo is an inactive substance that may be given to the control group of patients in a study. This substance looks like a medicine but does not contain any medicine.
Protocol A Clinical Trial Protocol is a detailed description of the design and procedures of a research study. The protocol provides information on what is being researched, why it is being researched, how the research will be conducted and when the research will begin and end.
TGA (Therapeutic Goods Administration) The TGA is an Australian organisation that regulates the testing, manufacture and use of medicines and devices. Medicines and medical devices must be approved by the TGA before they can be made available commercially to the public.
Many factors can influence the effectiveness of a clinical trial and whether the results of the trial are valid. These can include:
Single-blind studies In blind studies either the participant or the doctor is unaware of which treatment they are receiving. In these studies, doctors are aware of the treatment that the patient is receiving.
Double-blind studies In double-blind studies both the doctor and the participant are unaware of which of the listed study treatments the participant is receiving.
Blind and double-blind studies Minimise the chance of biased reporting when participants or doctors discuss the effects of the treatment. Blind and double-blind procedures lead to a more effective study.
Control Groups In clinical trials, there are usually at least two groups. One is an experimental group which is given the new treatment being studied. The other is a control group which is given a standard treatment currently available on the market. If standard treatment is unavailable, the control group is given a placebo (a look-alike pill with no active medicine). Control groups help ensure that the outcomes of the new treatment are not biased by patients’ beliefs.
Randomisation Randomised trials are clinical trials where participants are assigned to a treatment group on a random basis. This means that patients are assigned to groups irrespective of their age, gender, medical condition or any other similar factors. These sorts of trials are more reliable.
Sample size This refers to the number of patients involved in the study. Usually, the more people involved in a trial, the more reliable the results of the study will be.