On his frequent trips from North Carolina to Indiana, 11-year-old Heath Davis can often be spotted sporting his black TADPOL backpack, embellished with a cartoon of a bright green tadpole perched on a lily pad. But the backpack is more than travel gear — it represents his participation in an important clinical research study led by pediatric endocrinologists at the Indiana University School of Medicine and Riley Children’s Health.
TADPOL is an acronym for “TArgeting type 1 Diabetes via POLyamines.” The cartoon serves as a clever mascot for a study aimed at finding a new treatment for Type 1 diabetes, a disease that develops when the immune system mistakenly attacks the pancreas’ insulin-producing beta cells and affects blood sugar levels.
Because there is currently no cure, people with Type 1 diabetes must rely on lifelong insulin treatments to manage the condition. Without it, they are at risk of serious, life-threatening complications.
“I started using the bathroom a lot and drinking a lot of water,” Heath remembered about his early symptoms. “I also lost seven pounds and just didn’t really feel right. That’s when my mom said we should probably get checked out.”
Heath’s mother, Miriam Davis, is a research nurse with experience caring for patients with diabetes. When she noticed his symptoms, she quickly used a blood glucose meter to check his blood sugar levels. The results showed a fasting blood sugar of 516 milligrams per deciliter (mg/dL), which was far above the normal range of 70 to 140 mg/dL. A visit to the clinic the following day confirmed their suspicions, and Heath began daily insulin therapy.
“Because of my background in research, I wanted to get him involved in the best opportunity possible,” Miriam said. “I knew of new therapies trying to preserve the beta cells that are getting destroyed with Type 1 diabetes, but the studies near me weren’t for his age group.”
While searching for clinical trials enrolling children with Type 1 diabetes, they considered a study site in Florida, but the family ultimately chose Riley Children’s. Miriam had formerly worked at Riley and knew he would be in good hands with the diabetes experts in Indiana. Heath qualified for two IU School of Medicine studies focused on preserving the body’s own insulin production. They selected the TADPOL trial because it was a better fit for their schedules and included travel accommodations.
The TADPOL trial is investigating the drug difluoromethylornithine (DFMO) — already approved by the U.S. Food and Drug Administration for treating African sleeping sickness and neuroblastoma — to determine whether it can also improve beta cell health in people with Type 1 diabetes. Since most available therapies require injections, the trial is also exploring whether an oral pill could serve as a more practical option.
“We know that at the time of a Type 1 diabetes diagnosis, most people are still making some of their own insulin. However, over time, they lose more and more of those beta cells in their pancreas that make insulin,” said Emily K. Sims, MD, an associate professor of pediatrics at the IU School of Medicine and the study’s lead investigator. “This process happens even more quickly in kids than adults, so if you want to have the best chance of preserving the most beta cells possible, earlier is better for treatment.”
TADPOL is a double-blind placebo study, meaning some participants take the drug while others receive pills with no active ingredients. To be eligible, participants must be between the ages of 4 and 40 and newly diagnosed with Type 1 diabetes. Focusing on these qualifications allows researchers to thoroughly evaluate whether the drug can help preserve insulin production in a larger population, building on earlier studies that showed promise in smaller groups. The TADPOL trial is part of multiple efforts to study DFMO’s potential in treating the disease.
“Long term, we hope that we will be able to combine DFMO with other therapies as part of a combination to durably preserve insulin secretion in people with Type 1 diabetes,” said Sims, who is also a physician-scientist at the IU School of Medicine’s Herman B Wells Center for Pediatric Research and Center for Diabetes and Metabolic Diseases, and a pediatric endocrinologist at Riley.
The Davis family will not know whether Heath received the drug or the placebo until the study concludes in a few years. In the meantime, during his year of participation, he works with his doctors at home in North Carolina while also receiving additional support from the IU clinical trial team. The team, organized by clinical research coordinator Ellie Moreau, is in contact with Heath's family every few weeks for check-ins to help with diabetes management as well as in-person appointments every three months.
“It’s a big commitment, but Heath and his family really understand the importance of these kinds of studies,” Moreau explained. “This is how we, and researchers around the world, learn more about Type 1 diabetes and potential future treatments. We would not be able to complete these kinds of studies without committed families like Heath's.”
Heath passes the time by playing games during his long monitoring appointments, but he also embraces the chance to learn more about diabetes and meet new people. The Davises encourage other families with new diagnoses to seek out clinical trial opportunities and participate, even if it seems daunting, because it could lead to cutting-edge therapies. Heath expressed that participating in the TADPOL trial has been a “really fun and cool experience” and understands his involvement contributes to a greater purpose.
“I hope that this research can lead to there being a cure for diabetes one day,” he said. “I think it's important so researchers can understand more of what this disease does and how it works so that eventually there will be a time when we don't even have to worry about it.”
