Clinical trials are research studies designed to test new medical strategies or treatments and determine their efficacy for specific conditions. Furthermore, they contribute to medical knowledge while furthering healthcare provision.
Trials typically follow a multi-phased approach to keep participants safe while answering various research questions. Phases 0 and 1 are often the initial steps taken in such trials.
Phase 0
Researchers conducting translational research must conduct clinical trials in humans to test whether their therapy will have its intended medical impact. This process of clinical trial evaluation known as translational research takes a treatment from laboratory to patient in a series of closely monitored tests that measure the safety and efficacy of therapies – these help researchers decide whether or not to continue testing; their results help guide future decisions or discontinue testing if found unsafe or ineffective.
Pre-clinical animal models provide the first step in translating new therapies, testing their efficacy in more realistic settings than laboratories, and providing invaluable data about potential side effects or toxicities of potential therapies. Researchers can then conduct pre-clinical trials of any potential therapies and evaluate them as part of translation efforts.
This information will form the basis for designing a trial to test out therapy on human patients. Early clinical trials tend to involve healthy volunteers or those with specific health conditions who consent to participate. Every trial will have specific eligibility criteria that determine who may or may not take part based on factors like age, sex, disease type/stage, and previous treatment history.
Comparable with conventional first-in-human trials, phase 0 approaches tend to be safer as they use low doses and short exposure times to accurately extrapolate to therapeutic-level exposures. Furthermore, phase 0 trials allow more rapid assessment of viable candidates, saving time and resources otherwise spent on nonviable drugs.
Once preclinical and phase 1 trials are complete, developers may submit a marketing application to the FDA for approval of their product for sale to the public. They must first provide results of two large controlled clinical trials before their product will become commercially available for sale.
Phase 1
Researchers conducting safety trials of potential drugs on healthy volunteers or people suffering from the condition they are studying. Trials usually last several months and typically include 20 to 100 participants who receive their first-in-human dose either orally or intravenously and are monitored closely for adverse reactions.
Researchers use clinical trial management to gain an understanding of how new treatments act on human bodies (pharmacodynamics), and their rate of absorption, distribution, metabolism, excretion, and elimination (pharmacokinetics). Results from such tests can then help shape future phases of research studies.
In some instances, therapies have already undergone preclinical testing on animals and have passed all three phases without issue; allowing research teams to bypass Phase 1 altogether and move directly onto Phase 2. Sponsors, or drug developers, still must submit an Investigational New Drug application with the FDA before undertaking clinical studies; however, if they follow guidelines to ensure participant safety while also considering how their research might be perceived by others they have more freedom in designing trials than otherwise possible.
Researchers must also gain an understanding of whether new treatments are effective at preventing, diagnosing or treating diseases or conditions. In Phase 2, researchers analyze new drugs or therapies with larger patient participants to assess their efficacy as well as any side effects and determine their best route of administration – for instance, oral or intravenous administration.
Phase 2
Once researchers identify an effective therapy from preclinical research, they initiate human trials. Trials at this stage tend to be smaller than in Phases 0 or 1, as researchers test various dosages to find out the safest level and effectiveness for each individual. They will also observe side effects and how quickly metabolizes it will work within their bodies to understand how well it works.
If a drug shows promise in phase 2, it advances to phase 3. This phase of clinical trials requires randomizing large groups of participants who receive either the new medication or an existing therapy, with studies lasting several years to verify its safety and efficacy.
Researchers then conduct additional trials on specific groups such as women or older adults to ascertain if certain populations find the drug more effective and to customize how it’s being used.
Once researchers have their investigative drug ready for FDA review, they can file for FDA approval. An experimental medication will receive approval if two large, randomized phase III trials demonstrate its safety and efficacy over placebo treatments in treating its condition of study.
Once a drug has been approved for market, doctors can prescribe it to their patients; however, researchers will continue to monitor its safety and efficacy postmarket through what’s called Phase 4 studies; such studies could look into factors like long-term effects or how best to administer the medicine.
Phase 3
After researchers conduct lab- and animal-based trials on therapies, they conduct clinical trials with people to test them further and ensure safety and efficacy. This process, known as translational research, takes therapy from lab to clinic where it can treat disease effectively. Each phase of a clinical trial provides valuable data that allows scientists and doctors to make informed decisions regarding the safety, side effects, and efficacy of potential treatments.
Phase 0 of any clinical trial aims to assess the safety of an investigational drug or device by gathering small groups of healthy volunteers or people living with the health condition under study, who typically participate for several months – during this time investigators observe how it’s taken and absorbed in their bodies while also keeping tabs on symptoms, health outcomes and quality of life measures.
Phase 1 of a clinical trial involves testing an investigative medication in healthy volunteers or those suffering from the health condition being studied. Investigators administer small doses to these people to see how it impacts them and any possible side effects, with its duration depending on each study; most drugs will pass through this phase before entering Phase 2.
Phase 2 clinical trials involve administering investigational medication to a larger group of patients with the health condition being studied and comparing its performance against existing treatments or placebo. If it shows superiority over existing approaches, researchers move on to Phase 3, which it aim to confirm efficacy while further assessing safety.
Phase 4
The final phase of clinical trials entails monitoring the effectiveness and safety of therapies that have been approved, looking out for any unexpected side effects missed during earlier testing as well as conducting further research to find out how well an approved therapy works with individuals from diverse age, race, gender or medical condition backgrounds.
At this stage, we must verify whether a treatment does what it claims it does to move on to larger and better trials that are more likely to benefit patients. Furthermore, such studies provide important lessons about how best to utilize drugs or therapies in everyday situations and whether they surpass existing treatments in effectiveness.
At this phase, the therapy is administered to large patient participant populations ranging from several hundred to several thousand participants. Studies involving these therapies often compare them against an existing treatment or placebo while also gauging their tolerability – how comfortable participants felt participating in the research study.
Once treatment passes this phase and is safe and effective, physicians can recommend it regularly for use. Although this phase is exciting, gene and cell therapies often take years before making their way from laboratory to clinic.
Researchers must adhere to stringent protocols during clinical trial processes to protect participants and ensure accurate results. A detailed plan for such trials, known as a protocol, sets forth criteria participants must fulfill, procedures used, and how long the study will last.
