While great strides have been made in children’s leukemia care during the past 50 years, statistics have remained grim. For acute myeloid leukemia (AML), the most common type, 5-year survival rates were just 69% for children younger than 15 between 2009 and 2015. Patients who do survive past adolescence face high risks of future complications.
Specialists say the challenges hindering more progress include a lack of clinical research, an emphasis on competition over cooperation, and sparse insight into how best to adjust adult leukemia treatments to children.
“Our project aims to find better treatments, more targeted treatments, that will leave children with fewer long-term health problems as adults. We want them to not just survive but thrive,” Gwen Nichols, MD, chief medical officer of LLS, said in an interview. “What we’ve had was not working for anybody. So we have to try a different approach.”
The LLS Pediatric Acute Leukemia (PedAL) Master Trial launched in spring of 2022. Seventy-five study locations from Nova Scotia to Hawaii are now recruiting patients up to age 22 with known or suspected relapsed/refractory AML, mixed phenotype acute leukemia, or relapsed acute lymphoblastic leukemia (ALL).
The 5-year trial expects to recruit 960 participants in the United States and Canada. Clinics in Europe, Australia, and New Zealand also are taking part.
“Pediatric oncologists should know that PedAL, for the first time, is providing a cooperative, seamless way to interrogate [the genomics of] a child’s leukemia,” hematologist/oncologist Todd Cooper, DO, section chief of pediatric oncology at Seattle Children’s Cancer and Blood Disorders Center, said in an interview. “It is also providing a seamless and efficient way for children to be assigned to clinical trials that are going to be tailored towards a particular child’s leukemia. This is something that’s never been done.”
In North America, all trial participants with relapsed AML will undergo genetic sequencing for free as part of the screening process. Clinics “can’t always access genomic screening for their patients,” Dr. Nichols said. “We’re providing that even if they don’t participate in any other part of the trial, even if they go and get another available therapy or go on a different trial. We want them to know that this is available, and they will get the results. And if they’re looking for a trial when they get those results, we have trained oncology nurses who will help them navigate and find clinical trials.”
In PedAL itself, one subtrial is now in progress: An open-label phase 3 randomized multicenter analysis of whether the oral leukemia drug venetoclax combined with the intensive infused chemotherapy treatment FLA+GO (fludarabine, high-dose cytarabine, and gemtuzumab ozogamicin) will improve overall survival compared to FLA+GO alone. Ninety-eight subjects are expected to join the 5-year subtrial.
“We expect within the next year to open three or four different subtrials of targeted therapies for specific groups of patients,” E. Anders Kolb, MD, chief of oncology and hematology at Nemours Children’s Health in Delaware and cochair of the PedAL trial, said in an interview. “Over the course of the next few years, we’re going to learn a lot about the natural history of relapsed leukemia – we don’t have a ton of data on that – and then how targeted therapies may alter some of those outcomes.”
Discussions with multiple drugmakers are in progress regarding the potential subtrials, he said.
The PedAL strategy addresses the lack of new drugs for children with AML, Seattle Children’s Dr. Cooper said. One main reason for the gap is that childhood leukemia is much less common than the adult form, he said, so a lot of drug development is geared toward adults. As a result, he said, new drugs “are geared towards adults whose leukemia is not as aggressive. Whereas in children, the acute leukemias, especially AML, are quite aggressive and need therapies that are often more intense.”
In addition, he said, “we have only recently become aware of how AML is biologically much different than in adults.”
In AML, Delaware’s Dr. Kolb explained, “there are many different phenotypes – ways that these cells can look and behave. But we treat them with a single regimen. What I like to tell families is that we’ve got a few tools in our toolbox, but they all happen to be sledgehammers. The key to the challenge in AML is that it is a molecular disease, but we’re treating it with therapies that were developed 40-50 years ago.”
In PedAL, the goal is to figure out the best ways to target therapy for the specific types that patients have. On this front, the genomic screening in the trial is crucial because it will identify which patients express certain targets and allow them to be assigned to appropriate sub-trials, Dr. Coooper said.
What’s next? “LLS has planned for this to be ongoing for the next 5 to 7 years, so that we can get a number of studies up and running,” Dr. Nichols said. “After that, those studies will continue. We will hope that most of them can be self-funded by then.”
As for cost, she noted that the PedAL trial is part of the society’s Dare to Dream Project, formerly known as the Children’s Initiative, which focuses on pediatric blood cancers. The project, with a fundraising goal of $175 million, focuses on research, patient services and survivorship.
”We have a whole range of services, travel assistance, copay programs and educational resources that doctors may want to use as a valid source of information,” she said. ‘When I was in practice, patients were always asking me, ‘Do you have anything I can read or take home to give my son something about his disease?’ LLS has good-quality, patient-level information for patients. We welcome people contacting us or going to our website and taking advantage of that for free.”
Dr. Nichols and Dr. Kolb report no disclosures. Dr. Cooper reports academic funding from LLS.