While in many ways similar to pharmaceutical drug development, medical device development must work through some unique challenges, including:
- Variations in complexity — Devices may have multiple different constituent parts, including hardware, software, and medicinal components.
- Very different purposes — Almost all drugs are therapeutic, while devices may be therapeutic, diagnostic, monitoring, supportive, surgical, and more. Regulations regarding device development must account for, and be tailored to, all of these possibilities.
- Much longer timelines — While some drugs do have long-term effects, most are metabolized by the body quickly. In contrast, implanted medical devices may undergo dynamic changes in function and safety over years or even decades.
These factors have a major impact on the medical device development cycle, which can be broken down into five major stages. The outcomes of each stage have a direct effect on subsequent ones. Additionally, less-than-optimal outcomes may lead to some backtracking to a previous step rather than a complete abandoning of the project.
The first stage of a device’s development is its initial invention. This is soon followed by classification, which governs most aspects of the development process. Classification is generally made based on device type and assessed risk, with specific classifications in the U.S. and E.U. that can differ significantly.
2. Preclinical Research
At this stage, a device undergoes prototyping not yet for human use. These prototypes are then tested in controlled laboratory settings using in vitro and in vivo methods. From these tests, preliminary data regarding the device’s safety and efficacy are gathered. When it comes to medical devices, this stage is largely focused on evaluation of safety and biocompatibility. For example, typical assays include genetic and reproductive toxicology screens that look for possible carcinogenicity or unintended impacts on reproductive health.
3. Clinical Research
Once past the preclinical stage, testing in human trials begins. It’s important to note that these trials take place in phases that differ from drug trials:
- Pilot or exploratory studies that include 10–30 patients and are designed to evaluate preliminary safety and performance.
- Pivotal studies made up of 150–300 participants that determine clinical efficacy and look for adverse events.
- Post-approval studies continue after a device has been released to the public. They evaluate long-term safety and efficacy data. For devices like permanent prosthetic implants, the findings of these studies are the most clinically useful but may take decades to gather.
During the clinical research stage, it’s important to determine whether any adverse events that occur during a clinical trial could be attributed to the device being tested. For regulatory purposes, these are called serious adverse device effects. All device deficiencies should be reported to the appropriate regulatory body.
4. Regulatory Review
Data produced and compiled during the clinical research stage is then presented to the relevant regulatory authority. From there, the device is either approved and goes to market or is denied approval. Under the latter conditions, developers may go back to previous stages to build a more robust application for resubmission.
5. Post-Marketing Surveillance
As long as a medical device remains in use, its development is never completely over. Post-marketing surveillance can be considered a long extension of clinical research. During this time, developers supervise continuous monitoring and data collection after a product has been introduced to the public. Such long-term data may be used to guide clinical decisions or future medical device development.
If you’re interested in learning more about medical device development, definitely check out our white paper on medical device development pathways to approval!