Clinical trial without placebo: what is an active-controlled trial?
Many patients considering participation in a clinical trial have one major concern: that they may be receiving a placebo - an inactive therapy that has no curative effect. This is a perfectly understandable concern, as the patient is making a large commitment by becoming a participant in the study. When receiving a placebo, there is a risk that the patient will lose the desire to continue participation to the end due to lack of any effects.
Therefore, it is important to know that not all clinical trials use placebos, especially when a proven treatment for a disease already exists.
In some studies, the design provides a comparison between a new investigational product and an established standard therapy. This means that every patient in the study receives active treatment, whether it is the standard or the new treatment being studied.
What is this type of study?
In studies of this type, participants are divided into two groups:
Group A receives the standard treatment already used in medical practice.
Group B receives a new investigational treatment that is expected to be more effective or have fewer side effects.
The aim is to find out whether the new treatment is at least as effective (or more effective) than the therapy already available.
The ethical basis: the Helsinki Declaration
The use of this design is based not only on scientific logic but also on internationally accepted ethical principles. With the Fourth Revision of the Declaration of Helsinki in 1996, the World Medical Association clearly states that:
"It is not ethical to use placebos when an effective standard therapy exists, except in strictly limited cases."
This change was made after strong criticism of a study in which some participants were denied an already proven effective therapy (zidovudine) to prevent mother-to-child transmission of HIV. From this point on, active-controlled trials have been imposed as the standard in cases where there is an existing treatment.
Why is this important for the patient?
The main advantage of this type of study is that there is no risk of the patient receiving a placebo, i.e. a completely inactive treatment. Each participant receives real therapy, which increases the feeling of safety and ethicality. In addition, even if the patient is allocated to the standard treatment group, they receive a therapy that is considered to be the best currently available.
This is particularly important in more serious illnesses where interruption or absence of treatment is not ethically acceptable.
Conclusion
Active-controlled clinical trials combine advances in medical science with an ethical obligation to the patient. They provide the opportunity to access new therapies without the risk of receiving a placebo when there is already a proven standard of care. This makes them a preferred and ethical choice for both researchers and participants. At Unimed Medical Center, we also conduct active-controlled trials.
