The ethical and legal codes that govern medical practice also apply to clinical trials. Any human clinical trial must, at least, adhere to the international guidelines of the Declaration of Helsinki and the standards of the host country. The Declaration of Helsinki was developed by the World Medical Association (WMA), as a set of ethical principles for the medical community regarding human experimentation. An example of the use of these guidelines is when a person is assigned to a control group, the investigator may use an active comparator instead of a placebo as the placebo may violate their right to receive the best available treatment.

Before a trial can begin, it is first reviewed by one or more medical-scientific ethics committees. A Human Research Ethics Committee (HREC) is made up of experts who review and approve research proposals involving human participation. They must ensure that all proposed research is ethically acceptable and complies with endorsed standards and guidelines. The committee determines if there is a good reason to do the trial and whether it is safe for patients. The trial must be appropriately planned and the investigators leading the trial must be competent and qualified. Assessment requires review of data from previous experience, including pre-clinical and clinical studies. Any payments to patients enrolled in a trial are strictly overseen by the HREC to ensure that patients do not feel coerced to take part in the trial by overly attractive payments. Participants should not have to pay for any procedure specifically related to a clinical trial program, but patients, or their health care insurance system, may have to pay for current standard of medical care.

Informed consent is an important legal and ethical step. It involves a process of learning the key facts about a clinical trial before deciding whether or not to participate. Informed consent is also a continuing process throughout the study to provide information to participants. If new benefits, risks, or side effects are discovered during the study, the investigators must inform the participants. The investigators must explain details of the study, such as its purpose, duration, required procedures, key contacts, true risks and potential benefits. Investigators must also include an understanding that the subject may be assigned to the control group. Informed consent is not a contract, and the participant may withdraw from the trial at any time and for any reason.

In New Zealand only one application needs to be submitted to a HREC for multicentre trials, which covers all sites where the trial will be undertaken. For multicentre trials in Australia applications have previously been submitted to an HREC at each site. However this will be overcome with the introduction of the Harmonisation of Multi-centre Ethical Review (HoMER) project. The HoMER project “aims to develop a nationally harmonised system of scientific and ethical review process involving multi-centre health research”. This will ultimately allow investigators to submit just one application and reduce considerable delays and additional costs. The National Health and Medical Research Council (NHMRC) established the HoMER project as a result of a working group paper submitted to the Australian Health Ministers’ Advisory Council (AHMAC). In the 2007 Federal Budget, $5.6m was allocated to the HoMER project over a period of three years to work towards single review for multi-centre clinical trials.