Armed with personal experience and the knowledge that most cancer research — and even treatment plans — are geared toward adults, Arrieta turned to legislators in Washington D.C. to prove that children with cancer deserve more of a fighting chance.
"I still question, why couldn't someone do this 20 years ago?" Arrieta said. "Even if we could never have saved Alex, at least kids like him could have died with more dignity.
"Alex was tortured. No child should ever have to go through that much pain."
The whole story originated from a single headache. Then, Alex started complaining about pounding on his head daily. Soon, the bruises began to appear.
The Arrietas visited pediatricians, eye doctors and dentists to try to get to the bottom of Alex’s symptoms. Finally, Alex's pediatrician drew a full blood count, and everything changed.
His results showed barely any red blood cells, white blood cells or platelets.
"They came down Friday afternoon, and I knew right away it was leukemia. I just couldn’t say what type," said Arthur Provisor, the oncologist who diagnosed Alex.
From that day forward, with the exception of a single week, Alex spent the next six months in the hospital. Doctors immediately started blood transfusions — within days Alex was receiving around-the-clock chemotherapy.
Over the next few months, Alex experienced severe side effects including nausea, ulcers, kidney failure, respiratory failure and two heart attacks.
"Anytime he woke up from a nap or from a night's sleep he would say 'hand me my bucket,'" Arrieta said in a recent interview. "That was his body’s way of reacting to being in a conscious state. Sometimes he would throw up for a minute, 10 minutes or an hour."
In 2018, an estimated 10,590 new cancer cases will be diagnosed among children under the age of 14 and an estimated 1,180 deaths will occur among childhood cancer patients, according to the American Cancer Society.
While death rates in pediatric cancer have declined by nearly 70 percent over the past four decades, it is still the leading cause of death by disease in American children.
Dr. Martin Johnston, chief of pediatric hematology and oncology at Renown Children's Hospital in Reno, Nevada, was one of three doctors who treated Alex at Savannah's Memorial University Medical Center.
Johnston says that across the board, there has been a lot of success with treating childhood cancers in recent years. For example, the survival rate for the most common childhood cancer, acute lymphoblastic leukemia, rose from about 5 percent in the 1960s to 90 to 92 percent today, he said.
"But that still leaves 8 to 10 percent of children who are not surviving, and that’s where I think Brandon’s focus is appropriate," Johnston said.
Alex's cancer, acute myeloid leukemia, is most common in adults. The overall five-year survival rate for children with acute myeloid leukemia has slightly increased over time, but still remains at about 60 percent to 70 percent, according to the American Cancer Society.
Instead of receiving treatment from child-specific drugs, most children with cancer are given the same drugs approved for adults, just at adjusted doses.
While traditional chemotherapy is proven to help cure childhood cancer, the toxicity of the drugs can cause lasting side effects on children, including significant learning disabilities and higher risks of heart disease, stroke, infertility and second cancers.
Johnston said most of the drugs he uses daily as a pediatric oncologist have been around for decades and were developed to treat adult cancers.
"Most benefits in terms of better outcomes (for pediatric cancer patients) have not come from new, breakthrough drugs," Johnston said.
But it’s a different case for adult cancers.
In the past 20 years, more than 100 new adult cancer drugs have been approved by the U.S. Food and Drug Administration. Only three were specifically developed to treat pediatric cancer, according to the Coalition against Childhood Cancer.
"Kids don’t represent enough of the population, so they’re not looked at as separate," Arrieta said. "But we’re discounting the value of a child’s life by looking at it with that perspective."
As of March 2018, the American Cancer Society had $36 million in grant funding devoted to all categories of childhood cancer combined. Compared to other forms of cancer, that number is low. Breast cancer, for example, was receiving $91 million and colon cancer was receiving $55 million, according to the society's website.
The rarity of childhood cancers — less than 1 percent of all cancers diagnosed in the U.S. each year — makes them difficult to study and discourages pharmaceutical companies from developing innovative treatments.
In addition, pediatric oncologists have a limited numbers of investigators and limited political clout.
"Pharmaceutical companies need to stay in business ... If they spend all that money on a drug to treat 15 patients a year, they’re going to go broke," Johnston said. "You need to have a source of financial support to drive that forward and the only way that’s going to happen is if the government steps up to the plate. And the only way that will happen is if the public steps up and asks for it."
After six months of debilitating chemotherapy, Alex went into remission.
In January 2016, Alex's cancer had returned. And this time, he had limited treatment options because of the toxic effects the previous chemotherapy had on his body.
Alex's best chance at survival, according to his father, was a drug regimen that had only been used on five other children.
All five of those children, however, had died.
"In childhood cancer, after 'X' number kids die, they find out there's not a sweet spot for a particular drug," Arrieta said in a recent interview. "And even if they do find a sweet spot, that's still not a solution, because over two-thirds of children that survive cancer end up with lifelong issues."
Alex’s last blood test didn’t show any leukemic cells. But it also didn’t show the creation of any new, healthy cells either. His bone marrow had shut down.
"The chemo had obliterated them all," Provisor said. "He died because he had no defenses. His body couldn't wait for the bone marrow to possibly come back."
Arrieta blames the adult-centered chemotherapy for his son’s death.
"The treatment they gave him — it’s what killed him," Arrieta said. "His body never recovered from it."
If Alex would have survived, his father said he would have needed a heart transplant, a kidney transplant and a bone marrow transplant.
"That is where a massive disconnect is with any potential solutions for children with cancer," Arrieta said.
"... We’re not headed in the right direction."
While Alex was undergoing treatment, the Arrietas started the nonprofit organization Lambs for Life, as a way to carry on Alex's mission to send care packages with stuffed lambs to every child in the U.S. diagnosed with pediatric cancer.
The mission touched people across the country — from celebrities to comedians to politicians — and Arrieta used his platform as a way to start seeking answers about the lack of drugs and funding for childhood cancer.
When Alex died in April 2016, Arrieta's work took on a larger advocacy role.
"Alex had a huge heart," Arrieta said. "He always cared for other kids more than himself. This is really just an extension of that."
Around the first anniversary of Alex's death, Arrieta made a trip to Sen. Lindsey Graham’s office in Mount Pleasant to discuss the issues he sees with the treatment and overall classification of pediatric cancer.
Less than a month later, he was traveling to Washington D.C. and advocating for necessary changes to pediatric cancer with 12 members of the U.S. Senate Appropriations Committee's subcommittee on health, which controls funding for the National Cancer Institute.
With the help of Graham's office, Arrieta soon racked up enough support to tack on a committee report focused on pediatric cancer to the 2018 U.S. spending bill.
The $1.3 trillion spending bill was signed into law by President Donald Trump on March 23 with the report on pediatric cancer attached.
The report on pediatric cancer formally states for the first time that the federal government recognizes that treating childhood cancer is fundamentally different from treating adult cancer. It also requires the National Cancer Institute to produce a report "within 120 days after enactment of this act on how the NCI is focusing on the unique needs of children."
According to Arrieta, the report represents the first of a five-phase approach to restructuring the National Cancer Institute in order to separate pediatric cancer from adult cancer. The following steps include a hearing with the director of the National Cancer Institute on May 17, as well as crafting committee reports on pediatric cancer for the next three upcoming spending bills.
Ultimately, Arrieta's goal is to create a division within the National Cancer Institute dedicated to pediatric cancer.
"It’s like a football game," he said. "We’re trying to do a few yards at a time instead of throwing a hail Mary all the way."
A spokesperson for the National Cancer Institute said it is close to finishing the report.
Arrieta believes the report will be the first change in what could become "the largest impact to childhood cancer policy reform in the history of cancer," he said.
But based on prior experience trying to spark change with elected officials, Alex's former doctor remains apprehensive.
"What I worry about — broadly speaking — is that all the effort expended by advocacy groups and all the desk-thumping that goes on in Washington amounts to window dressing and ultimately nothing really comes of it," Johnston said. "I think it’s going to take people like Brandon to monitor the situation and make sure things are accomplished."
A few months ago, Arrieta received an email that said there were no more requests to change his language for the committee report.
In the midst of what should have been a reason to celebrate, he broke down.
"It’s just too bittersweet," he said.
"I’m grateful to God and the people who are supporting what we’re doing, but I would take it all back to have Alex alive."