Most clinical trials are conducted to test a medical compound, a device or a diagnostic test in human volunteers and/or patients to add evidence and medical knowledge regarding the treatment of diseases. This information involves both efficacy and safety of a new treatment.
Before a clinical trial can start, a detailed protocol must be developed. A clinical trial protocol determines why and how a clinical study is conducted. This protocol is usually designed by experts and investigators from the company (sponsor) and/ or organizations interested in conducting the clinical trial. The clinical trial needs to be approved by internal review boards at trial sites and by the federal health authorities such as the FDA or Health Canada. The protocol will include the reason behind the study, what will be tested, procedures of testing, participants’ eligibility criteria, number of participants, and length of study. Inclusion criteria are the factors that determine subjects’ eligibility for the trials. Exclusion criteria determine which subjects are disqualified from participating. Inclusion and exclusion criteria may include age, gender, type of disease, disease stage, current medical treatment and medical history.
As sites become active and approvals are received, patients begin enrolling. The speed at which patients are enrolled in any clinical study depends on a myriad of factors. The most important factor in enrollment is, of course, inclusion and exclusion criteria. If the disease being studied is rare or if there is strict inclusion and many exclusion criteria, then enrollment can be slower, as compared to a trial for a common disease with few exclusion criteria.
Clinical trials may be funded by healthcare companies, including biotechnology and/or pharmaceutical companies, academic and medical centers, government agencies and other organizations. All entities interested in conducting clinical trials would determine the budget necessary for each trial and raise the necessary capital for the study.
Clinical studies may be conducted at multiple sites including hospitals, universities, and community clinics. It is not uncommon for large clinical outcomes trials to enlist several hundred trial sites in multiple countries. The location is usually determined by who is conducting the study and the availability of the patient population. Clinical studies are led by a principal investigator (PI), who is often a medical doctor, and she/he is supported by a group of doctors, nurses, social workers, and other healthcare professionals. The duration of the clinical study varies from trial to trial, depending on the phase of the trial and what is being investigated.
The next blog will discuss the final steps in the clinical trials series.