Clinical Trials

❘❙❚■ Chapter 1 | Randomized Clinical TrialsWhat is a randomized clinical trial?A clinical trial evaluates the effect of a new drug (or device or procedure) onhuman volunteers. These trials can be used to evaluate the safety of a new drug inhealthy human volunteers, or to assess treatment benefits in patients with aspecific disease. Clinical trials can compare a new drug against existing drugs oragainst dummy medications (placebo) or they may not have a comparison arm(see Chapter 2). A large proportion of clinical trials are sponsored bypharmaceutical or biotechnology companies who are developing the new drug,but some studies using older drugs in new disease areas are funded by healthrelatedgovernment agencies, or through charitable grants.In a randomized clinical trial, patients and trial personnel are deliberately keptunaware of which patient is on the new drug. This minimizes bias in the laterevaluation so that the initial blind random allocation of patients to one or othertreatment group is preserved throughout the trial. Clinical trials must be designedin an ethical manner so that patients are not denied the benefit of usualtreatments. Patients must give their voluntary consent that they appreciate thepurpose of the trial. Several key guidelines regarding the ethics, conduct, andreporting of clinical trials have been constructed to ensure that a patient’s rightsand safety are not compromised by participating in clinical trials [1–3].Are there different types of clinical trials?Clinical trials vary depending on who is conducting the trial. Pharmaceuticalcompanies typically conduct trials involving new drugs or established drugs indisease areas where their drug may gain a new license. Device manufacturers usetrials to prove the safety and efficacy of their new device.Clinical trials conducted by clinical investigators unrelated to pharmaceuticalcompanies might have other aims. They might use established or older drugs innew disease areas, often without commercial support, given that older drugs areunlikely to generate much profit. Clinical investigators might also:• look at the best way to give or withdraw drugs• investigate the best duration of treatment to maximize outcome• assess the benefits of prevention with vaccination or screening programsThus, different types of trials are needed to cover these needs; these can beclassified under the following headings.2