What Are the Different Phases of a Clinical Trial?

Medical research always starts with clinical trials. Treating an incurable disease is extremely challenging, but, as was the case for HIV, medical research scientists found a way to alleviate the symptoms before discovering a cure.

Clinical studies are mandatory to ensure that the treatments are safe and effective. It usually takes years of clinical studies before new treatments and medications get permission from Health Authorities to be available for commercial use.  Continue reading as we take you through the Pre-clinical trials and the four phases of clinical trials.

Pre-clinical Trails

Pre-clinical trials are research studies conducted in laboratory settings using animal models or cell cultures. They evaluate the safety and efficacy of potential new drugs or treatments before testing in humans. Pre-clinical trials typically have three phases: pharmacology, toxicology, and pharmacokinetics. The results of these studies determine whether a drug or treatment is safe and effective enough to proceed to clinical trials.

Phase 1: Establish safety, dosage, and side effects

Phase 1 clinical trials are the first stage of testing in human subjects. They assess the safety of a potential new drug, device, or other medical intervention. In Phase 1 trials, a small group of healthy volunteers (usually 20–80) receive the test drug or device. The primary goals of Phase 1 trials are to determine the safety, side effects, and tolerability of the drug or device.

They also include tests of the drug’s pharmacokinetics, which is how the body absorbs, distributes, metabolizes, and excretes the drug. Researchers may use Phase 1 trials to determine the appropriate dosage of the drug or device.

Phase 2: Determine the efficacy

Phase 2 clinical trials are conducted after Phase 1 clinical trials are completed. The primary goal of Phase 2 clinical trials is to determine whether the drug or device is safe and effective in treating a particular condition. These trials involve a larger group of people, typically between 100-300 participants, and evaluate the effectiveness and safety of the drug or device being tested.

In this phase, researchers also look for side effects and determine the optimal dosage for the drug or device. By the end of this phase, researchers will better understand the drug or device’s safety and efficacy.

Phase 3: Confirm efficacy and safety in a larger study

Phase 3 clinical trials are the final stage of clinical testing before a drug is approved for marketing by regulatory agencies such as the US Food and Drug Administration (FDA). Phase 3 trials involve large groups of people (1,000–3,000 or more) and are conducted at multiple clinical sites. The primary purpose of Phase 3 trials is to demonstrate the safety and effectiveness of the drug in the target population.

During Phase 3, the drug is tested in a real-world setting to determine its effectiveness in treating the intended condition. The study group is typically divided into two groups, with one group receiving the drug or device and the other group receiving a placebo or standard of care. The trial results determine if the drug or device is safe and effective enough for general use.

Phase 4: Long-term safety and efficacy monitoring

Phase 4 clinical trials are conducted after a drug has been approved for general use and is available on the market. The purpose of Phase 4 trials is to monitor the drug’s safety and identify any rare or long-term adverse effects. Additionally, Phase 4 trials can evaluate the drug’s effectiveness in various patient populations and study the drug’s efficacy at different doses and durations. In some cases, Phase 4 trials may also assess the cost-effectiveness of the drug.

Who may take part in clinical trials?

Anyone without serious underlying medical conditions may participate in clinical trials, subject to certain qualifications. Generally, clinical trials seek volunteer participants who meet specific criteria, such as age, gender, health history, and current health status. Eligibility requirements vary from trial to trial. Potential participants should discuss the risks and benefits of clinical trials with their doctor before deciding to participate.

What motivates volunteers to participate in clinical trials?

There are many different motivations for people to volunteer for clinical trials. These motivations can include altruism, curiosity, desire to help find cures for diseases, and financial reasons, as many clinical trials offer compensation for time and travel expenses. Additionally, people may be motivated to volunteer for clinical trials out of charity duty or to be part of a larger scientific effort. Finally, some people may volunteer for clinical trials out of a personal connection to the condition being studied, such as if they or someone they know has the disease.

Participating in a Clinical Trial at Biotrial

Understanding the different phases of clinical trials gives you a better insight into what to expect and helps you make an informed decision regarding your participation.

At Biotrial, we mainly conduct phase I clinical trials. Our participants’ safety is prioritized and is closely monitored and observed throughout the study. Want to hear more about our clinical trials? Feel free to contact us at Biotrial.

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