Behind the Scenes:
Setting the Stage for a Statistically Sound Clinical Trial
This is the fourth installment of a Behind the Scenes series about how Children’s Oncology Group (COG) clinical trials work. The first article focused on how research ideas become actual studies. The second delved into the complex work of COG Protocol and Research Coordinators. The third highlighted the critical contributions of Clinical Research Associates. The story below explains how statisticians are pivotal in developing and guiding clinical trials that aim to improve the lives of children and families affected by cancer.
Todd Alonzo, PhD speaks at the General Session of the COG Fall Group Meeting 2025.
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Statisticians aren't just number crunchers — they build the scientific foundation for COG’s clinical trials and help guide them at every step. Their work plays a crucial role in making sure our clinical trials are safe, that they’re designed to best answer the questions at hand, and that their results can be trusted. This ensures that each COG trial has the best opportunity to move us closer to giving every child with cancer access to better treatments and cures.
Before a trial begins, statisticians help investigators decide the main question the study will answer, how many patients are needed, and which results will indicate whether an intervention really helps. They also design fair ways to compare treatments, so the results aren’t based on chance or influenced by bias. |
During the trial, statisticians watch the data closely to keep patients safe by following reported side effects closely and making sure the study goes as planned. As cancer research becomes more complex, especially with medicines tailored to different gene types or tumor markers, statisticians use special methods to make sense of complicated data and adjust the study design when needed.
At the end of the trial, statisticians analyze all the results and help explain what they mean in a clear, accurate way. They work with investigators to share findings with medical journals, the public, and the health agencies that approve new drugs. In the end, they turn complex data into clear answers that everyone involved can trust when deciding how to treat cancer.
Guiding trials from start to finish
At COG, statisticians are involved in trials from the get-go, serving alongside surgeons, oncologists, radiologists, nurses and other members of the COG disease committees.
“One of our strengths in being part of a disease committee is to take what clinicians want to research and translate that into testable hypotheses that we can actually study in a clinical trial,” said COG Group Statistician Todd Alonzo, PhD, Professor of Research in the Department of Population and Public Health Sciences at the University of Southern California.
At the end of the trial, statisticians analyze all the results and help explain what they mean in a clear, accurate way. They work with investigators to share findings with medical journals, the public, and the health agencies that approve new drugs. In the end, they turn complex data into clear answers that everyone involved can trust when deciding how to treat cancer.
Guiding trials from start to finish
At COG, statisticians are involved in trials from the get-go, serving alongside surgeons, oncologists, radiologists, nurses and other members of the COG disease committees.
“One of our strengths in being part of a disease committee is to take what clinicians want to research and translate that into testable hypotheses that we can actually study in a clinical trial,” said COG Group Statistician Todd Alonzo, PhD, Professor of Research in the Department of Population and Public Health Sciences at the University of Southern California.
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Alonzo and his colleagues in the COG Statistics and Data Center are a lot like chess masters, using math, computer programs and careful planning to plot next steps with every future move in mind. “Even from the beginning, you’re always thinking about the end game,” Alonzo said. First, they evaluate past research and talk with doctors to understand the disease and what the new treatment is trying to do. Then they use numbers and models to determine how many patients should join the trial and how the results should be measured to make meaningful comparisons. As the trial goes on, they organize the data, check for patterns, and make sure the information is accurate. And they use special formulas, graphs, and tables to see whether the treatment really helps patients. |
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Their analyses and input can sometimes lead to important, midstream changes in how studies are conducted.
For example, Alonzo played a key role in narrowing the scope of a study (AAML 1831) looking at a new combination of chemotherapy for kids with acute myeloid leukemia (AML).
Researchers had hoped that patients in the study would have better outcomes for a new treatment than the standard treatment at the time. But as Alonzo and his team analyzed data and evaluated how patients were responding, he and the research team determined that patients without a specific genetic mutation weren’t faring better with the new treatment.
Based on this insight, the study was stopped for patients who didn’t have a specific genetic mutation.
“It was disappointing that the therapy didn’t have broader impact,” Alonzo said. “But it was gratifying to be able to zero in on the people it potentially could help, and to spare other participants from trying an experimental treatment that would not have helped them.”
For example, Alonzo played a key role in narrowing the scope of a study (AAML 1831) looking at a new combination of chemotherapy for kids with acute myeloid leukemia (AML).
Researchers had hoped that patients in the study would have better outcomes for a new treatment than the standard treatment at the time. But as Alonzo and his team analyzed data and evaluated how patients were responding, he and the research team determined that patients without a specific genetic mutation weren’t faring better with the new treatment.
Based on this insight, the study was stopped for patients who didn’t have a specific genetic mutation.
“It was disappointing that the therapy didn’t have broader impact,” Alonzo said. “But it was gratifying to be able to zero in on the people it potentially could help, and to spare other participants from trying an experimental treatment that would not have helped them.”
Todd Alonzo, PhD
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Filling funding gaps with philanthropy
The majority of funding for COG clinical trials, including the work by Alonzo and his colleagues at the COG Statistics and Data Center, comes from National Cancer Institute grants. But that funding doesn’t cover the full cost of the work, and this gap will likely grow larger amid proposed federal cuts. That’s why private donors are vital. “Statisticians aren't exactly top of mind for most funders, but it's an area where philanthropic support can make a pivotal difference in every aspect of a study," Alonzo said. |
Even in today’s uncertain funding climate, researchers like Alonzo wake up every day driven to keep moving forward toward better treatments for children.
“Seeing a treatment become the standard of care, meeting people who are treated on your trial … it's incredibly rewarding,” he said.
Alonzo has spent his entire career at COG, joining right after earning his PhD in Biostatistics 25 years ago. He’s served as COG’s head statistician for almost a decade and can’t imagine a more fulfilling focus for his life’s work, or a more talented network of colleagues.
“The study teams for COG’s trials are leading experts in their fields,” he said. “Science evolves at such an incredible rate. It’s exciting to continue learning and making discoveries that move us closer to giving more kids with cancer the chance to live long, healthy lives.”
“Seeing a treatment become the standard of care, meeting people who are treated on your trial … it's incredibly rewarding,” he said.
Alonzo has spent his entire career at COG, joining right after earning his PhD in Biostatistics 25 years ago. He’s served as COG’s head statistician for almost a decade and can’t imagine a more fulfilling focus for his life’s work, or a more talented network of colleagues.
“The study teams for COG’s trials are leading experts in their fields,” he said. “Science evolves at such an incredible rate. It’s exciting to continue learning and making discoveries that move us closer to giving more kids with cancer the chance to live long, healthy lives.”