Technology is constantly changing the world, making processes more efficient, improving accuracy, and removing human error. While that is true in many fields, technology has been a bit slow to make its impact on the world of clinical trials for both new prescription drugs and new medical devices. However, the world of in silico trials is beginning to change how the field of medicine develops new treatments.
What does in silico mean?
In the world of clinical trials, there are three different types of research experimentation that is conducted: in vitro, in vivo, and in silico. The term in vitro means “in the glass” in Latin, and it refers to experiments that are conducted in a controlled environment, such as a petri dish. The experiments are carried out on cultures of cells or tissues, which is a small amount of living cells that is grown outside of a person and is contained within a lab. The in vitro experiments also may be conducted on tissues and organs from cadavers, or, in the case of medical devices and sometimes drugs, it refers to a “bench test,” where the product being tested is tested in an environment that matches the conditions under which it would be used by a patient.
The term in vivo is Latin for “within the living,” and an in vivo experiment is when an experiment is conducted on a whole living organism, such as a mouse or a human being. This type of experimentation is often conducted toward the later part of a clinical trial, after it may have gone through an in vitro round of experimentation. Researchers use in vivo experimentation because it helps them better understand what impacts and side effects a person may experience rather than the impacts on just a specific piece of tissue.
The most recent addition to the world of clinical trials is in silico, which was coined in 1989 during a workshop held in Los Alamos, New Mexico, by Pedro Miramontes, a mathematician from National Autonomous University of Mexico when he described a biological experiment that was conducted solely on a computer. The term in silico means “performed through a computer simulation,” and while it is still quite new, more and more researchers and developers are turning to it to create their next medical breakthrough.
What are the steps to a clinical trial?
Clinical trials are an important part of the world of medicine. It is through clinical trials that new prescription drugs, vaccines, and medical devices are tested. These trials also are how researchers and developers refine their approaches to ensure their product is both safe (it does not harm the health of the person using it) and effective (the product actually improves the health of the person using it).
Clinical trials typically are conducted in stages that advance from the early beginnings of a new drug or device, to potentially testing on tissues or animals, and then to the final testing in actual people. When humans become involved in the trial, there are three phases:
- Phase I: This phase usually involves a small number of patients recruited for the experiment, usually between 20 and 100 people. The limitation here is, of course, that it is difficult for researchers to see how a new drug might interact with a variety of people as the diversity of this group typically is quite limited.
- Phase II: This phase typically involves a slightly larger number of recruited patients, from 100 to 300, but the limited number means researchers typically don’t notice any of the less common side effects a small percentage of the population may experience from taking the drug or using the device being trialed.
- Phase III: This is the phase that is the most expensive and time-consuming. It can involve anywhere from 300 to 3,000 people, and it is used to see how the new product may impact a wide variety of people.
Why are in silico trials used?
Researchers use in silico trials because they can add more information to a trial in its earlier phases and can reduce some safety concerns by replacing human patients with virtual ones.
- In Phase I trials, an in silico trial could help improve the accuracy of dosage estimates and improve effectiveness by analyzing a much larger sample of people than typically are recruited in this phase. Using a computer model would allow for researchers to increase the biological diversity of their initial “patients” going through Phase I.
- In Phase II trials, in silico trials could shorten the length of the trial or reduce the number of them, or even partially replace humans needed for a Phase II trial.
- In Phase III trials, which are the most expensive in time and money, in silico trials can use Phase II results and determine the possible outcomes of a Phase III trial before making the investment needed to carry the trial further. Using computer modeling could help researchers understand what might need to be fixed or determine whether the Phase III trial will be successful as is.
Using in silico trials could end up saving time, money, and patient health in the long run. It’s another way that technology can carry us forward quickly and effectively in the complicated world of clinical trials.
Written by Sheena McFarland
