April 16, 2024

Your guide to understanding phases of cancer clinical trials

Cancer clinic medical staff reviewing images

Clinical trials can be an important resource for patients at every stage of their cancer diagnosis, but understanding the scientific terms, study protocols and process can be intimidating to many patients.

That’s why UW Health | Carbone Cancer Center prioritizes educational resources, including a team of Clinical Trial Nurse Navigators and the new uwhealth.org/cancertrials webpage, to ensure patients have accurate information about how clinical trials work and how their care and safety will be prioritized at every step.

“Having a good, educational source of information about clinical trials is so important because there are a lot of myths and misconceptions out there,” said Sarah Kotila, Clinical Trials Navigation Team Manager at Carbone Cancer Center.

One of the most common questions patients have is what the different phases of a clinical trial mean. Read more about each step in the important process of approving new cancer treatments.

Phase 1

In this initial step of a clinical trial, the research staff is looking at the safety and appropriate dosage of giving a new treatment. They also watch for side effects. The number of patients enrolled on phase I trials are small — there are typically fewer than 50 patients involved.

Kotila often hears patients ask if phase 1 trials are safe. She explains that any cancer treatment comes with potential risks and benefits, whether it’s established clinical care or treatments being tested in clinical trials. With clinical trials, a team of experts is closely monitoring the patient’s care and frequently checking in to see how the patient is doing and feeling.

“Patients should know there can be risks and benefits to any cancer treatment they receive, and this is the same with clinical trials,” she said.

Kotila adds that to get Food and Drug Administration approval to start a clinical trial there has been considerable lab and preclinical research already done to prepare their research for this important next step.

Phase 2

Once a study has cleared its phase I benchmarks, it can move into phase 2. Researchers at this stage continue to monitor safety and are focused on whether the new treatment method is effective for certain diagnoses.

“In phase II, they’re having more people enroll to see if the treatment is effective in specific types of cancer” she said. “It’s still a smaller number, usually less than 100 people.”

Because they are measuring whether the approach is effective, phase 2 typically lasts several months to two years to measure changes over time. Researchers also continue to monitor for side effects that were not seen in phase I with the smaller group.

If the treatment proves to be effective for certain types of cancer, it can advance to phase 3 status.

Phase 3

This is the final step of testing before a treatment can be approved by the FDA for standard clinical use. The new treatment is being compared directly to existing standard of care treatments to determine if the new treatment is as good or better than our current treatments. The patient pool is at least several hundred people to get a widespread view of patient effects and validate the findings.

Placebos, which are inactive substances designed to look like study medication, can be used to randomize patient effects in the study and help preserve integrity of results when evaluating a new treatment. Placebos are rarely used in cancer treatment clinical trials. Kotila reassures patients who are afraid of placebos that they will still get treatment when needed.

“It would be unethical to not treat a cancer patient that needs treatment. Patients in these phase III randomized drug trials may get standard of care plus a placebo or standard of care plus the new treatment being tested, but they will always be treated,” she said.

FDA approval

So what happens if you’re part of a clinical trial and the study medication receives FDA approval? Dr. Mark Burkard, a physician-scientist who leads several clinical trials at Carbone, said the study’s sponsor can choose to stop the trial or continue studying long-term effects.

“In most cases, the sponsor will continue the trial to collect additional information about how the drug works, allowing the patient to choose (if they continue),” Burkard said. “Most patients choose to continue the trial. Some choose to stop the trial, if for example, they live far away and can get the same medicine from an oncologist close to home.”

Learning more

Kotila said patients who are considering clinical trials and have more questions can contact the Clinical Trials Navigation Team at (608) 262-0439 or clinicaltrials@cancer.wisc.edu. If a patient would like to schedule an appointment or be seen for a clinical trial at UW Carbone, please contact our intake team at (608) 262-5223.