Phase 1
Tests if a new treatment is safe for use as well as finding the best way to administer the treatment. The goal of this phase is to find out the safety level and determine the highest dose that can be given. The trial usually involves a small number of people starting off with the smallest dose, and gradually increasing after side effects have been examined. Placebos do not get used in the first phase and rare side effects to the treatment might not be present until later phases due to phase 1 having a low number of participants. Phase 2 begins once the treatment is determined to be safe.
Phase 2
Includes more people to determine if a treatment is effective. Aims to obtain initial data on whether the treatment is effective on those with a particular disease. Continues to examine safety and side effects. The participants in this trial are given the dose found to be the safest from phase 1 and everyone typically receives the same dose. Placebos are not used in phase 2 trials. Phase 3 begins once enough patients benefit from the treatment and the side effects aren’t too bad.
Phase 3
Compares the safety and effectiveness of the new treatment against the current approved standard treatment. This phase usually will have randomized patients to receive either standard or new treatment. Double-blind studies might also be conducted, which is where both the doctor and the patient do not know which treatment they received. This phase usually contains at least several hundred participants and is done across the country at the same time. Might be offered in community hospitals or doctor’s offices. This phase might contain the use of placebos. Once the trail shows a new drug is more effective than the standard treatment, a new drug application is submitted to the FDA for approval, and once the treatment is approved, phase 4 starts.
Phase 4
After FDA approval, treatments will be watched over a long period of time. This is because the effects might still not be fully known and there might still be some unanswered questions about the treatment. This phase looks at treatments already approved by the FDA and they are available for doctors to prescribe. This is the safest trial because the treatment has gone through extensive studies already and other aspects of the treatment are examined, including quality of time and cost effectiveness.
Pilot stage
In this first stage, a small, preliminary study to gather safety and device performance data is perfomed. This stage will guide future device modifications and designs.
Traditional feasibility stage
In the second stage, safety and efficacy of the final device is assessed in patients. This will guide the design of the pivotal study.
Pivotal stage
The third stage will involve a large study to verify clinical efficacy, safety, and risks. This stage is driven by statistics from previous stages.
Post-market stage
This stage will monitor long-term effectiveness, safety, and usage in the general population.
Medical device trials are typically controlled studies that rarely use placebos, such as sham surgeries or inactive devices. The use of placebos in medical device trials is controversial due to the fact that sham procedures tend to be high risk and are viewed as unethical by some. They might sometimes be randomized, and blinding is rare. Crossover studies are sometimes possible, but not always.