Information for Potential Participants on Clinical Trials
This information is designed to answer questions you may have if you have been
invited to take part in a clinical trial. This may be your first time on a clinical trial or you
may have been involved in one before, but either way the idea of participating in a trial
may seem daunting. Below is a brief run-down on what clinical trials are, and what is
involved if you agree to participate in a clinical trial.
1. What is a clinical trial?
A clinical trial is basically essentially a scientific study that involves human participants.
Clinical trials are often done by a pharmaceutical company in collaboration with
independent investigators. The aim of clinical trials is to investigate whether a medicine
is reliable, safe and effective for a particular disease or condition.
Clinical trials are used by authorities such as the Ministry of Health (MoH) in New
Zealand, or the Food and Drug Administration (FDA) in the USA, to decide whether the
medicine should be allowed on the market. After marketing approval, trials continue to
work out in more detail who else may benefit from the medicine, and whether this
medicine has any other applications.
Clinical trials also allow doctors to measure the extent of the medicine‟s effect, so they
can predict with some confidence how much benefit other patients with the same
condition will get, and whether there are any potential side effects doctors need to warn
patients to look out for.
2. What happens in clinical trials?
A clinical trial can be designed in a number of ways.
In randomised controlled clinical trials, large numbers of people are recruited to
participate in the study. The people who have been recruited are divided by random
allocation into two or more groups, so that the groups are similar in terms of age, sex,
illness and other factors that could have an impact on the study results. One group is
given the medicine being studied, the other group is given a placebo (a tablet which has
no active medicine) or a standard treatment for the disease.
You may have read that many clinical trials are „double blind‟ trials. This means that
during the course of the trial none of the participants, clinical trial staff or study staff
know who is taking the study medicine and who is taking the placebo/standard
treatment. This way nobody knows who is taking what until the end of the trial, and so
no one can affect the outcome of the trial in any way. The participants are given the
study medicine or the placebo/standard treatment to take in the same way as their
family doctor would request. At the end of the trial, the results from the people taking
the study medicine are recorded and then compared with the results of the people
taking the placebo/standard treatment, using statistical measures. This way
researchers can get an accurate picture of what people can expect if they begin taking
There is a method called “unblinding” which shows the researcher what trial medication
the participant is taking should they need to know because of a side effect.
3. What are the stages in clinical trials?
There are various stages or phases involved in the journey of the development of a new
medicine, from the laboratory until the local pharmacy where it is available to
Initial Testing: Following the initial development of the medicine, which can take
several years, it is extensively tested in the laboratory and on animals to work out its
actions, to determine what the side effects might be, and to make sure it is not harmful.
After the initial development and testing, clinical testing begins and this requires Ministry
of Health approval and Ethics Committee review. Clinical trials are divided into three
phases of study, each phase involving greater numbers of people.
Phase I: Here the focus is mostly on the safety of the medicine. Studies are normally
conducted on healthy volunteers, usually numbering between 20 to 100 people.
Researchers study the effective and tolerated dose and how the medicine is absorbed,
broken down and eliminated by the body, as well as identifying any side effects at
different doses. This phase generally lasts several months. Usually about two-thirds of
medicines progress past phase 1.
Phase II: Here the focus is on the effectiveness of the study medicine in treating the
intended disease. In this phase there is also some emphasis on side effects and risks
in participants with existing health problems. Generally, a few hundred patients
participate in phase II trials, which take longer than phase I trials. Only about one third
of medicines successfully complete this phase.
Phase III: In this phase the focus is on safety, effectiveness and determining the right
dose to treat the disease. Several hundred people with the disease in question may
participate. By using such large numbers of people, less common side effects will
emerge. Of the medicines that complete phase II, most also successfully complete
4. How do researchers know the medicine won’t have unwanted effects?
As mentioned above, part of the purpose of clinical trials is not only to assess benefits
but also to see if any unwanted side effects emerge, and how severe or common they
are, as well as the benefits. Any side effects that occur in the group taking the study
medicine are compared to the side effects seen in the placebo group or the standard
treatment group. Most of the side effects in the placebo group are due to unrelated
illnesses such as stomach upsets and colds. Only by having the two groups can the
researchers determine whether an unwanted effect is due to the medicine or an
5. What happens with the results?
The final results of the clinical trials are reported in the medical press, without
individuals being identified. They are available for doctors, so that they can make
scientifically-based assessments of the benefits and risks for each patient. A copy of
the results can be obtained from your doctor, however, this may be some time after you
have completed the trial. The data may be used to obtain permission from the Ministry
of Health to market the product in New Zealand.
6. Who is involved in clinical trials?
You have been invited to participate in a clinical trial because you have a disease that is
the focus of the study. The doctor who is managing your study is known as the
investigator. S/he is responsible for the overall management of the study. Each
investigator is supported by a team of co-investigators, sub-investigators and study
co-ordinators who are responsible for your medical care while on the trial and will
always put your safety and interests first. Each person will have defined responsibilities
in the running of the trial. You will be given the name of the person you need to contact
for appointments or advice.
7. How are clinical trials managed?
All parties (investigators, study co-ordinators and pharmaceutical company employees)
involved with the development and testing of the study medicine must follow the study
protocol. This sets out in detail the process and design of the study, the treatment(s) to
be used and the measurements that will be required. In New Zealand all trial protocols
must be approved by a health and disability ethics committee, which may be contacted
if you have any concerns.
If you would like advice as to your rights as a participant in a clinical trial you may
approach a Health & Disability Consumer Advocate by phoning
0800 20 55 55 (Upper North Island)
0800 42 36 38 (Mid/lower North Island);
0800 37 77 66 (South Island).
8. What do I have to do if I participate?
As a participant in a clinical trial, you too have responsibilities.
Before agreeing to participate in the trial you should read the participant information
sheet and understand what participation in the trial will involve. You should ask the
Investigator any questions necessary to understand the study.
Participation in clinical trials is voluntary. If you decide not to participate, this
will not affect your ongoing healthcare. If you do decide to participate, you may
withdraw at any time without having to give a reason and this will not affect your
By signing the Consent Form you are agreeing to participate in the study.
It is also important that you take the medicine as prescribed by the study staff. This
involves taking your medicine at the requested times and attending regular check-ups at
the clinic. During check-ups, you will be asked to bring your tablets with you to ensure
you are taking the right number with the specified treatment.
Failure to follow the trial instructions may cause an adverse event for which you may
not be fully compensated by the company.
If the trial is sponsored by a pharmaceutical company, your participation will not be
covered by ACC but will instead be provided by the sponsor pharmaceutical company.
The Investigator will provide you with further details.
An ID card is issued to each participant in a study trial. The ID card provides
information on the study number, the Investigator and Study Co-ordinator contact
details and the participant‟s medication.
9. Are there any risks?
There is always some risk associated with taking any medicine and there will also be an
additional risk in taking any new medicines. If a side effect does occur during a clinical
trial and it is decided that it is due to the study medicine, you may choose to withdraw
from the study or your doctor may withdraw you from the study. Sometimes the trial is
10. Are there any other checks on clinical trials?
During a clinical trial all data are checked by a monitor. The monitor is employed by
the pharmaceutical company to manage the study and to check that all evaluation data
are correct and entered without errors. This is to ensure all ethical and good clinical
practice guidelines are being followed by the doctors and medical team.
All clinical trials may be subject to an audit which is undertaken either by the
pharmaceutical company or by local or international regulatory authorities.
Points to remember:
It is important to keep your appointments
Please bring your unused medicine back to your doctor/study nurse
Please contact your doctor or study nurse if you have any concerns
Please carry your participation ID card with you at all times