Clinical Trials or Clinical Research is any trial or research involving human subjects directly or using specimens or information derived from humans. It is a process to prove the effectiveness and safety of a new drug before obtaining marketing approval. Such prospective biomedical or behavioral interventions on participants aim to answer specific questions about biomedical or behavioral therapies, including new treatments (e.g., new vaccines, drugs, dietary choices, dietary supplements, and medical devices) and previously known treatments requiring further study or comparison. Clinical trials are divided into preclinical, Phase I, Phase II, Phase III, and Phase IV trials. Although the term "clinical experiment" was sometimes used interchangeably in the past, "clinical trial" is now the standard term, and "clinical experiment" is no longer used.
Clinical trials can be quite costly, depending on numerous factors. Trials can only be conducted after receiving approval from health authorities and ethics committees (IRB) in countries where treatment approval is sought. These bodies are responsible for evaluating the benefit/risk ratio of the trial. Approval from these bodies does not imply the treatment is safe or effective, only that the trial may proceed.
Depending on the product type and development phase, investigators initially enroll volunteers or patients in small-scale pilot studies, gradually moving toward larger comparative studies. The scale and cost of clinical trials can vary significantly, and they may involve a single country or multiple countries, as well as single-center or multi-center setups. Clinical trial design aims to ensure the scientific validity and reproducibility of outcomes.
The cost of clinical trials can reach billions of dollars per approved drug. They are funded by government agencies or by pharmaceutical, biotechnology, or medical device companies. Specific functions necessary for trials, such as monitoring and laboratory work, may be managed by outsourced partners like Clinical Research Organizations (CROs) or central laboratories.
Only about 10% of drugs that start human clinical trials eventually receive approval. (Source: Wikipedia)
This is a description of clinical trials as explained in Wikipedia. It’s quite lengthy.
So, what exactly is a clinical trial, in a nutshell?
It is research involving volunteers, conducted to expand medical knowledge with the goal of improving or preventing diseases.
Clinical trials can be broadly divided into interventional studies and observational studies.
This raises another question: What are interventional and observational studies?
- Interventional Studies: These are studies where intervention occurs; specific criteria are imposed, and participants must adhere to these criteria during the study. This is the primary method for regulatory clinical trials, testing the safety and efficacy of new or modified drugs/devices that are not yet marketed.
- Observational Studies: As the term suggests, these studies do not require strict adherence to specific conditions. Instead, they observe participants under routine clinical care, primarily for post-marketing safety investigations of approved drugs for approved indications.
In describing these research methods, the term "primary" is used because clinical trial methods are selected as the best approach after considering various conditions, including the disease, trial phase, participants, and study design. Thus, while interventional studies are mainly for regulatory clinical trials, and observational studies are mainly for post-marketing clinical trials, they cannot be divided into these two categories in a strict 100% dichotomy.
Summary
Clinical trials are an effort to find treatments or drugs that are more effective, more convenient, and safer for the targeted disease or condition.