Clinical trials are defined as studies in which specific interventions are given to participants in accordance with a protocol or guide that was created by the investigating researchers. Many medical devices are also interventions which must undergo similarly rigorous testing and development through clinical trials.
The Food and Drug Administration (FDA) has established three regulatory classes to which generic types of medical devices can be assigned.
Class I: Class I contains non-invasive medical devices which present the lowest level of risk. The malfunction of these devices poses very little threat to the patient and user. Examples of class I medical devices include wheelchairs and crutches. Most class I devices are 510(k) Exempt and do not require FDA approval.
Class IIa: Class II contains invasive medical devices which present low to medium risk. These are typically applied to the body for at least 1 hour but no more than 30 days. Examples of class IIa medical devices include hypodermic needles and dental fillings.
Class IIb: Class II contains invasive medical devices which present medium to high risk. These are typically applied to the body for over 30 days. Examples of class IIb medical devices include lung ventilators and bone fixation plates. All class II medical devices must receive FDA clearance, typically via a 510(k).
Class III: Class III contains invasive medical devices which present the highest level of risk. The malfunction of these devices poses significant threat to both the patient and user. Examples of devices in this class include pacemakers and prosthetic heart valves. Class III medical devices are strictly regulated and must receive FDA pre-market approval based on robust clinical evidence.
Medical devices and investigational medicinal products share a similar path to human testing.
Once a device prototype is created, it must undergo many cycles of preclinical testing to ensure the final product has the safest and most effective design before testing in humans can begin. Like with preclinical pharmaceutical research, researchers can evaluate medical devices at this stage via bench testing, technical testing, computer simulations, or animal testing.
For medical devices which require testing in clinical trials prior to FDA approval, an Institutional Review Board must review and approve key study documents, such as the protocol and informed consent forms. As with new drugs, the trial can only begin once the sponsor and site or sites who will test the device have received all necessary approval notices. However, one key difference between both interventions is the time to approval; the process for medical devices takes an average of 3 to 7 years, but for drugs, it can take as long as 12 years.
Unlike with pharmaceutical products, medical device clinical trials are divided into stages rather than phases.
Both classes of interventions can sometimes undergo a Phase 0, or first-in-human stage, study wherein 10-30 participants are recruited to collect early safety and performance data. This is the only point at which medical device trials will often enroll as many or more subjects than pharmaceutical trials.
Phases I and II are intended to test early formulations of a drug in up to hundreds of healthy humans and patients of the indication, respectively. In contrast, the corresponding traditional feasibility stage of medical device trials assesses the safety and efficacy of a nearly finalized product, only in 20 to 30 patients with the indication of interest.
New drugs and devices which reach the Phase III or pivotal stage, respectively, are further evaluated to confirm their safety and efficacy. Whereas drug trials can implement blinding and placebos, device trials are often only controlled with a group that does not receive the intervention. Phase III studies for drugs can contain hundreds to thousands of patients with the indication of interest, whereas pivotal stage studies for devices only contain hundreds of these patients.
At Phase IV, or the post-marketing surveillance phase stage, both types of interventions continue to be monitored for safety and efficacy in the general population.
Medical device clinical trials are run by a variety of highly trained healthcare professionals.
Most clinical trials of drugs at the site-level require an investigating physician, one or more clinical research coordinators or nurses, pathology staff, and third-party vendors. In comparison, medical device trials additionally require specifically qualified technicians, programmers, and medical imaging staff, as well as psychologists or physiotherapists, depending on the device.
Clinical trials for medical devices and pharmaceuticals share many of the same characteristics. Despite their few differences, medical device clinical trials, like those for drugs, play an integral role in helping approve safe and effective clinical interventions by collecting high-quality data. For more information on new and ongoing medical device clinical trials, visit https://clinicaltrials.gov.