A year after leukemia diagnosis, clinical trial brings hope

Callen Hoesman—Cal for short—flits like a hummingbird around the bright educational displays at the Kidzeum in Springfield on an early March morning. The precocious 5-year-old navigates climbing platforms and interactive exhibits, asking questions and chatting with his family as he moves quickly from station to station. 

On the second floor, Cal pushes the plunger on a giant syringe and a few minutes later tries on firemen’s outfits with his brother. 

His energy and exuberance seem normal in the child-friendly environment. ‘Normal’ is especially uplifting to his parents, who know Cal spent most of the last year battling leukemia. At far too young an age, the little boy has become overly familiar with medical apparatus like syringes, chemotherapy and clinical trials.

Cal’s father, Chad Hoesman, is the deputy regional superintendent of education in Greene County’s Regional Office of Education (ROE) and a pastor at First Christian Church in White Hall. Mom Regan is a counselor at the ROE’s alternative center. The family of six are enjoying the day in Springfield; Cal is joined by siblings Remy, 6, Cooper, 3, and 9-month-old Rory. 

Chad vividly remembers the day his son was diagnosed with leukemia. It was March 29, 2024—Good Friday of Easter weekend. His son had a wellness checkup scheduled in Springfield on the same day that Chad rang the bell to celebrate his final round of treatment for prostate cancer in Jacksonville. 

Cal had been suffering from lingering colds all winter. At the checkup his mom suggested a blood test to check for an iron deficiency. After the clinic visit, the family took a trip to the mall to meet the Easter Bunny and enjoy a dinner out.

The couple were discussing weekend plans on the drive home to White Hall when Regan’s phone rang. Cal’s blood test revealed he had B-cell acute lymphoblastic leukemia, or B-ALL. It’s an aggressive cancer that occurs when the bone marrow overproduces a specific type of white blood cell that helps the body fight infections. Too many of those cells can push out other healthy cells, making it hard for the immune system to fight off things like colds and pneumonia.

Chad and Regan would need to return to Springfield that evening to admit Cal to the hospital. They contacted family to watch the other children and packed overnight bags.

“That’s when the rollercoaster ride began,” said Chad.

Trust the experts

The Hoesmans met with Greg Brandt, MD, and Clare Zimmerman, MD, SIU Medicine’s pediatric oncologists who would be leading Cal’s care team. Dr. Brandt is a professor of clinical pediatrics and SIU’s principal investigator for research studies. Dr. Zimmerman is a Springfield native, SIU School of Medicine alumna and chairs the university’s Institutional Review Board.

Brandt explained that the survival rate for children with acute lymphoblastic leukemia (ALL) has dramatically improved over the past 20 years. Around 85% will be long-term, event-free survivors, although children with B-ALL still account for half of all pediatric ALL-relapses. 

To the Hoesmans, trust in the doctors became paramount. Their expertise at treating children with leukemia provided actual optimism and hope that Cal would come through what lay ahead.

“When we first started this journey, we could only imagine what he was going through,” Chad said. 

“We had all these questions and they would always answer them,” Regan said. “That first month everything seemed so dire, it feels like you’re drowning. And after that, you try to find your footing and you learn how to breathe underwater. And sometimes how to keep your head above the water.” 

To add to the stress, Regan was seven months pregnant when the family learned of Callen’s illness.

Through the initial medical care, the oncology staff made sure to mix positivity into the procedures. The local organization Bricks of Hope and the nurses kept Cal loaded with Legos for his overnight hospital stays and regular visits. 

When baby Rory was born in June, brother Cal was upstairs at HSHS St. John’s Children’s Hospital, receiving chemo. His new little sister became another bright spot in the family’s shared hospital routines.

A new option

At a visit soon after Rory was born, Dr. Zimmerman told the Hoesmans about a clinical trial for a new drug, blinatumomab, being tested for leukemia patients. Cal fit the criteria for the B-ALL study.

They discussed the benefits and risks and decided to enroll. 

“It was a no-brainer,” said Chad. “We thought OK, we can be part of something that could someday help other kids who have this, so we definitely wanted to be a part of it.”

The phase 3 study had been running for five years and would eventually include 1,440 children. 

The Hoesmans’ altruistic response is shared by many who consider joining a clinical trial. The potential to increase scientific understanding of a disease is how it can eventually be overcome. 

Other possible benefits of being part of clinical research include:

• Patients can play a more active role in their health.
• They may learn more about the disease or condition.
• Patients and caregivers may have access to new support groups and resources.
• Patients may have access to a potential new treatment for a disease before it becomes widely available.

This last benefit is the equivalent of receiving a golden ticket.

In the fall, the study group’s investigators ran data analysis that showed that their trial drug BLINCYTO® (blinatumomab) had allowed 96% of children to go disease-free for three years. 

The outcomes were so favorable that the trial was ended early, and the findings were shared with the participants and published. Blinatumomab was proven to be safe, effective and exceeded expectations at preventing relapses.

However, half of the children enrolled hadn’t received it. They were part of the control group that got the standard care treatments for comparison. Cal had been in this neutral group. But because the trial drug had been so effective, it was approved to add to the treatment plans for all the children.

Mom and Dad were ecstatic. “Super Callen,” as he sometimes refers to himself, would get to benefit from this breakthrough. 

“The timing was great,” said Chad. “He’s going to be fine. The best blessing of all may be that he never remembers any of this. It will be like, ‘Was I in the hospital then?’”

Cal’s maintenance schedule runs for 18 months. The Hoesmans have gone from seeing Drs. Brandt and Zimmerman once or twice a week to now once a month. 

“They were such a huge part of our lives this whole time, they are like family,” Regan said.

When big sister Remy talked about her upcoming ‘Dress Like Teacher’ Day at school, it gave Cal an idea. 

“He asked if he could dress up like Dr. Brandt and we could go see him,” Chad said. “We said sure. He’s like an uncle to Cal.”

The next day, they tracked down Dr. Greg Brandt as he was rounding at the hospital. It made for a moment that the veteran oncologist will never forget.

“I have seen a lot of 4-year-olds do adorable things. This ranks up there near the top,” he said.

If you'd like to learn more about participating in local clinical research studies, visit Clinical Trials or email sciresearchbc@siumed.ed.