Beyond Chemo: New Tools to Fight Cancer Offer More Options

By Jean Yaeger

Aiden Snyder responded with determination and positivity when his leukemia came back again and again and again after his initial diagnosis at age 4.

With each relapse, Aiden’s doctors tried a new approach to combat the rogue cells overtaking his bone marrow. Aiden received chemotherapy as well as drugs specific to his type of cancer, along with two stem cell transplants over the years. Another strategy involved tweaking some of his healthy cells in a lab, and then returning the altered cells to his bloodstream to zero in on and kill the cancer.   

The good news? Aiden, now 11 years old, has been leukemia-free since his second transplant in December 2020 at Cook Children’s Medical Center. He still goes in for monthly checkups to keep watch on his blood counts. Doctors are also monitoring the hardened red patches of skin that resulted as a side effect of his last treatment. 

A fifth-grader, he’s back in school and considering a nursing career someday, thanks to the inspiration of nurses who lifted his spirits during his frequent and extended hospital stays. “I just want to help people in that way,” he said.  

In September as we observe Childhood Cancer Awareness Month, we salute Aiden and celebrate the evolving research that makes today’s medical options more promising than ever for pediatric oncology patients.  

“Forty years ago, the hope would've been that they would survive. Now it's the expectation,” said Kenneth Heym, M.D., medical director of the Cook Children’s oncology program. “Aiden is a perfect example of a patient who continued to have the deck stacked against him. But with new emerging treatments and a positive can-do attitude and that desire to move forward, not only is he still here, but he is a success in every sense of the word.”

Aiden’s long battle against an especially aggressive type of cancer – leukemia with a genetic mutation called Philadelphia chromosome-positive (Ph+) – shows his grit, humor and resilience. His providers at Cook Children’s describe a boy with the unusual maturity and smarts to weigh in on medical decisions over the course of his care. Here’s how it unfolded.  

Round 1: Chemo and Meds

In May 2016, Aiden Snyder was a pre-kindergartener living in San Angelo with his mom and dad, Erica and Chris, and little sister Ella. His parents noticed puzzling bruises and a rash; a blood test the next day found that Aiden’s platelet count was dangerously low and dropping fast.  He needed expert care right away, so Cook Children’s sent a plane to fly Aiden and his mom to Fort Worth.  

“He was in scary bad shape,” Erica remembers. The bruises had been an early sign that cancer blasts were multiplying in the marrow, or spongy middle of his bones, crowding out the cells that make platelets. Our bodies need platelets to clot blood and to stop bleeding. “His marrow was packed full of leukemia.”

Aiden’s more resistant Ph+ type of leukemia required intensive chemotherapy with close follow-up at Cook Children’s. Aiden and his mom moved into the nearby Ronald McDonald House for the next 10 months while he completed the first phase of his therapy. In addition to chemo, he received another medication, called a tyrosine kinase inhibitor, which specifically targeted the genetic mutation in his Ph+ leukemia.  

“By combining those medicines with leukemia treatment, we actually have taken the cure rates for Philadelphia positive so much higher,” Dr. Heym said. “By adding these newer medications to chemotherapy, patients are doing much better.”

Aiden lost his hair, got nauseous and struggled with appetite. But he also enjoyed trips to the zoo and the playground when he felt up to it.  “Our outlook from the get-go was, ‘You're not a cancer patient. You're a little boy who happens to have cancer right now,’” Erica said.  

When his intravenous treatments ended, Aiden returned to San Angelo. For the next year, he took three oral chemo pills daily. “That was supposed to seal the deal, just make sure it doesn't come back,” she said. Six months after the final oral chemo pill, Aiden’s leg started hurting.

Round 2: Transplant

The leg pain that Aiden experienced in October 2018 was worse than typical muscle cramps, and Tylenol didn’t relieve the pain. It seemed suspicious, so the Snyders drove to Cook Children’s, where tests confirmed that his cancer had returned. The initial intensive and targeted therapies had failed, and Aiden now needed a stem cell transplant.  

Cook Children’s transplant coordinator Stephanie Tettleton explained that the process starts with intense chemo or radiation to wipe out the patient’s bone marrow before introducing cells from a matched donor. For Aiden’s transplant in January 2019, the donor cells came from stored umbilical cord blood obtained through the national registry.

“Think of it like a garden where you're going to get all the weeds out, get it ready, and then you plant new seeds. The new seeds are that new marrow or the stem cells that grow a new immune system. That's a very basic way to view a stem cell transplant,” Tettleton said.

Cook Children’s performs about 50 stem cell transplants annually. Lindsay Barkley works with Tettleton on the donor end and on patient education. Barkley pointed out that Aiden spoke knowledgeably with his doctors about stopping or starting medications. A positive outlook helped him cope, too.  

“Even when Aiden was going through terrible things, he would come in with a smile on his face,” Barkley said. “It helps to have hope and have a good emotional outlook that you can get through this together.”

Families need to know that because of the child’s compromised immune system after a transplant, he or she must be isolated for a year to prevent infections. Aiden returned to San Angelo and was homeschooled until he was cleared to return to school in person in January 2020. Within just a few weeks, Aiden came down with a horrible headache.

Round 3: CAR T-Cell Therapy

Fast-growing cancer cells were back and had made their way to his spinal fluids, where they clogged the ventricles in his brain and caused the headache. Aiden was flown to Cook Children’s once again. With this relapse, due to the pressure in his brain, Aiden suffered seizures.

“We ended up in the ICU. He was in very bad shape,” Erica said. “I wasn't sure he was going to wake up. And I wasn't sure if he did wake up, if he would be the same kid. He was completely unresponsive. It was very scary.”

Now what? Chemotherapy, targeted medicine and a stem cell transplant hadn’t stopped the cancer, but there were newer options available. The next recourse was CAR T-cell therapy, or chimeric antigen receptor T-cell therapy, which had been approved by the Food and Drug Administration only three years earlier. CAR T-cell therapy adapts the patient’s own T-cell infection fighters to recognize a protein marker on the leukemia cells. The treatment takes about four weeks starting when the patient’s T-cells are removed, then reprogrammed, and then infused back into the bloodstream. 

“It's wild. It's like science fiction,” Erica said, describing the leukapheresis technique that filtered Aiden’s blood to pull out the white blood cells, which were then reengineered in a lab and returned to his body. Aiden underwent the procedure in June 2020 at another hospital (CAR T-cell therapy became available at Cook Children’s later that year). 

While the initial results were promising, within months Aiden’s aggressive Ph+ cells mutated to avoid detection from his T-cells. The cancer was no longer expressing the characteristic protein that Aiden’s T-cells could recognize. In September 2020, a routine blood test revealed a very small amount of cancer that soon began replicating faster than they had seen in the previous relapses. Nine-year-old Aiden was almost out of options.

Round 4: Transplant, Again

Chris and Erica gave their son the freedom to decide what to do next. Devastated and in counseling, he wanted straightforward information about every scenario:

• A second stem cell transplant, which was risky so soon after the first transplant
• A few out-of-state options that offered no guarantee of better outcomes than the procedures he’d already attempted
• Do nothing more, an acknowledgment of the heavy physical and emotional toll the leukemia and treatments had taken

Aiden chose to do a second transplant at Cook Children’s. One of the potential side effects of bone marrow transplant is an immune response where the donor cells recognize the patient’s body as foreign and attack, causing what is called graft versus host (GvH). GvH can affect the patient’s skin, eyes, gut or other body parts, On the plus side, these donor cells can also recognize leukemia calls as foreign, providing a long-term immune response to reduce the risk of relapse, called graft versus leukemia (GvL). In order to better harness the GvL effect, Aiden’s mom was selected because she was a haploidentical, or half-matched, donor.

Erica was admitted as a Cook Children’s patient in December 2020. White blood cells were collected from her through the same process that Aiden’s cells had been collected previously, and the cells were delivered to Aiden in the hospital room next door. As expected, the half-match transplant resulted in the GvH effect, a mixed blessing. GvH showed up in Aiden as a widespread skin rash along with hardening of the skin and joint contractures. Over time and with medication, the GvH is starting to fade.

“The benefit is that the protection from the graft versus leukemia effect should last forever,’ said Richard Howrey, M.D., associate medical director of the Cook Children’s stem cell transplant program and Aiden’s transplant doctor.

“It's unusual to see a patient with this many relapses doing as well as he has been doing,” Dr. Howrey said. “Thanks to new medications which treat GvH and other complications associated with transplants, we're making good progress. Kids who wouldn't have survived in the past are surviving now.”

When you ask Aiden about his hospital memories, he mentions highlights like playing jokes on the nurses; hanging out with the therapy dogs; supervising while Dr. Heym mended a toy giraffe; and talking with anyone about Legos, Harry Potter books and zones of the ocean. “I feel like a lot of it is hard to forget,” he said.

What advice would he give to another child diagnosed with leukemia? “If you get up moving and playing, you won’t think about it as much.”

Child Life specialist Erin Loftus has been one of Aiden’s favorite companions at Cook Children’s since his first clinic visit. When he comes in for checkups these days, they play video games together. Even at a young age Aiden stood out for his ability to voice opinions and observations that shaped his care, she said.

“He's always been really good about telling us what he needs, what he wants, what works, what doesn't work,” Loftus said. “He’s had a very rough road, but because he has been able to speak to the doctors, I think it's kind of helped bridge that gap. He’s not afraid to say he didn’t like how something was making him feel.”

Dr. Heym said the staff appreciated hearing Aiden’s articulate perspectives and insights on how the treatments impacted him.

“This is his body and these are his feelings and his side effects,” he said. “Nobody is going to tell you better what's going on with them than the patient themselves. Being able to get that feedback from the patient lets them feel like a bigger part of what's going on.”

The Snyder family, meanwhile, moved last year to Crowley so they’d be closer to Cook Children’s if another emergency arises. Aiden’s mom now works as a Cook Children’s parent experience specialist. To a mother or father who feels like a helpless bystander in a medical crisis, Erica makes the point that parents are the experts on their own child. “If something doesn't sit right, we want you to tell us that. We want you to ask questions. We want you to be part of the conversation.”

Future of Cancer Care

Cook Children’s is among the research sites where clinical trials are leading to state-of-the-art breakthroughs in cancer treatments. Dr. Heym is excited about advances that hone in on specific characteristics of the disease – to eradicate the cancer, while causing minimal harm to the rest of the body. Medication and CAR T-cell therapy, for instance, are increasingly designed to target just the leukemia abnormalities.

“We have so much more at our disposal now than we did in the past,” he said. “It's ushered in this whole new revolution in oncology treatment where we're trying to get away from the shotgun approach of conventional chemotherapy and go more with the sniper rifle of these targeted therapies.”

Dr. Heym says Cook Children’s incorporates the new advances into a multidisciplinary, comprehensive approach to fighting childhood cancer.  

“We’ve built the kind of foundation here that allows us to provide every patient with the best chance of survival. And that's our goal. Even when we can't cure, we still want to care as much as possible.”