Aerial view of the UW–Madison health sciences campus.

Clinical Trials: How major advances in medicine happen

UW Health

When stakes are high, clinical trials rise to the challenge to keep moving medicine forward.

Today marks Clinical Trials Day, an internationally recognized date to honor the collaborative efforts of those who conduct clinical trials and those who participate in them and how their work contributes to public health and medicine.

The clinical trials community at UW–Madison is supported by the UW Clinical Research Office, a partnership between the University of Wisconsin School of Medicine and Public Health and UW Health.

Clinical trials are research studies in which experts examine new treatments, drugs, medical devices or interventions to determine what has the most benefit and least harm to yield the best patient outcomes, according to Dr. Nasia Safdar, associate dean for clinical trials.

“Any major advancement in medicine is the result of a clinical trial,” she said. “Medical conditions need treatments, and you can’t find out which treatment works best without a clinical trial.”

To determine which therapies are effective, researchers create clinical trials to test them in a group of human volunteers. Researchers use rigorous, methodologically sound techniques to track and analyze data and yield accurate results, Safdar said.

“Clinical trial participation should be viewed as part of an overall healthcare plan, rather than a ‘last resort’ treatment option,” she said.

There are four phases of clinical trials, according to Safdar.

  • Phase 1: Safety: First, a small group of healthy volunteers help determine safety through things like blood tests and questionnaires.
  • Phase 2: Efficacy: The next step is to evaluate the benefit and effectiveness in a small group of volunteers.
  • Phase 3: Next is a full scale, large volunteer group – typically thousands of participants – in a randomized clinical trial to understand the performance of the investigational product and learn more about any side effects that may occur.
  • Phase 4: Finally, after the Food and Drug Administration (FDA) has approved the drug, device, treatment or intervention, individuals receiving it in the “real world” setting will be monitored to ensure it performs as expected. Many participants in phase 4 of a clinical trial were not in the earlier phases.

There are more than 300 clinical trials ongoing at UW Health and the UW School of Medicine and Public Health for everything from cancer to aging to cardiovascular diseases to COVID-19, according to Betsy Nugent, chief clinical research officer, UW Health.

“The pandemic brought clinical trials into the spotlight as health leaders across the world quickly ramped up efforts to identify safe and effective vaccines to save lives,” Nugent said.

The safety measures involved in COVID-19 vaccine trials met the same rigorous standards as all clinical trials, but due to tremendous collaborative effort by clinical trial professionals, data were collected more rapidly than usual, she said.

“UW was at the forefront with COVID-19 vaccine clinical trials,” Nugent said. “We were the primary clinical trial site in the state for adult and pediatric COVID-19 vaccines.”

The COVID-19 vaccine trials showed how the community can play a powerful role in clinical research. Thousands of people responded when the COVID-19 vaccine clinical trials were announced at UW, she said.

“We are so grateful for the support from the community and for their willingness to help,” Nugent said. “We cannot do clinical trials without those who volunteer to participate.”

According to Nugent, diversity in participants is also vital. There can be important differences in how people of different races, ethnicities, ages, genders and other demographics respond to medical products, according to the FDA.

“Clinical trials need to represent everyone,” she said. “Participant diversity makes our clinical trial outcomes stronger and more credible.”

To learn more or find a clinical trial please visit