National physician-scientists band together to treat pediatric cancer
They say it takes a village to raise a child. The same could be said about finding a cure to NF1—the abbreviation for neurofibromatosis type 1, a genetic disorder that predisposes children to many forms of disfiguring cancers and neurodevelopmental conditions.
In medical terms, NF1 is called an orphan disease, a short way of explaining why most biotech and pharmaceutical companies aren’t particularly motivated to find possible cures. NF1 affects so few people (one out of every 3,000) that it offers limited opportunities to make money. In the for-profit world, that makes neurofibromatosis an orphan, even though it’s the most common genetic disease in humans, surpassing cystic fibrosis, Duchenne muscular dystrophy and Huntington’s disease combined.
Fortunately, there’s another realm where NF1 is more like a prodigal son than an orphaned child. As far back as the early 1990s, a group of research physicians embedded in the nation’s top academic health centers and research institutions have been studying NF1 to find better treatments.
Working together, these scientists form an all-star team that recently won a prestigious five-year, $12 million grant from the National Cancer Institute’s Specialized Programs of Research Excellence Initiative (SPORE). Awarded in 2015, it’s the first grant of its kind to fund research for treatment of pediatric cancers.
One of the key innovators of the grant proposal is principal investigator, D. Wade Clapp, MD, chairman of the Department of Pediatrics at the Indiana University School of Medicine and member of the Herman B Wells Center for Pediatric Research.
As a practicing physician at the Indiana University Health Melvin & Bren Simon Cancer Center and Riley at IU Health, Clapp has a steady source of motivation for this national research project: the children in his care and the circumstances that draw them.
Take, for example, the phone call he received one Thanksgiving morning from a young mother in California. Her three-year-old daughter had been diagnosed with plexiform neurofibroma, a slow-growing tumor that was blocking her airway and thwarting her growth.
Clapp and his colleagues at the IU School of Medicine (IUSM) had just published their first papers about Gleevec, an existing drug and one of the first to show favorable results against NF1 in mice and in patients. The family learned about the Gleevec research after three hospitals turned them away, giving them little hope for treatment. With no clear options, the child was on a trajectory to choke to death.
After their discussion, the family took a flight to Indianapolis and later enrolled their daughter in a clinical trial led by one of Clapp’s research colleagues, Kent Robertson, MD, PhD. The child’s participation in the trial diminished the size of her tumor by 40 to 50 percent and stopped its growth.
“At the time, she was a little girl about three years old, and she was tiny to boot,” Clapp says. “Now she’s an exuberant third-grader who is excelling in school, catching up on her growth, playing with other kids and riding horses. She’s a real character of a little girl, actually. I’ve got a picture of her here in my office.”
Since then, Clapp and his IUSM colleagues have partnered with pharmaceutical companies to move Gleevec and two other drugs forward after identifying their genetic targets through basic science at the Wells Center. The drugs were originally made for other conditions, but are now repurposed to treat NF1. “In all three of those drugs, we’re seeing a significant impact on children, adolescents and young adults,
but none of them are perfect,” Clapp says.
Despite their success in shrinking some tumors, Clapp says many patients do not get better. He often thinks about a little boy with severe paraspinal plexiform neurofibroma who did not respond to Gleevec. After participating in trials, the boy had surgery to relieve compression along his spinal cord and he still has life-threatening health problems related to NF1. “These two kids are the yin and yang of our work,” Clapp says. “There’s the excitement when we succeed, and the realization that we still have serious work to do.”
The SPORE grant is an extension of that work, an elaborate collaboration among Clapp’s research peers at eight institutions: IUSM, Memorial Sloan Kettering Cancer Center, University of California at San Francisco, the pediatric branch of the National Cancer Institute, the University of Texas Southwestern, Johns Hopkins University, the
University of Alabama-Birmingham and the University of North Carolina.
As one of the principle investigators, Clapp lobbied peers at each institution to get buy-in for the initial SPORE grant proposal, which contained a strategy for combining their massive body of research on three types of cancer.
The community of neurofibromatosis investigators is relatively small. They’ve shared models and experiments, and written papers and smaller grants together before. “Fortunately, several of us have worked together for a long time in different ways, so it wasn’t like cold-calling a bunch of people that you don’t know,” he says. “It was more like pulling together a group of friends to begin thinking about how to move this
initiative forward.”
The scientists are key leaders in the field who’ve already made significant contributions to NF1 discoveries at their respective institutions. The SPORE grant provides funding to do detailed molecular analysis of NF1 cancers and learn how they adapt (or don’t) to certain drugs. But the grant is not just a source of money to do experiments in preclinical mouse models; it’s a way to generate sophisticated and
detailed information from clinical trials that can’t be achieved otherwise. The
information will show how to stop tumors from developing resistance to therapy.
NF1 is a genetic disease that affects about 250,000 individuals in the United States and Europe, but the work Clapp’s group is pursuing also has important implications for a much larger population—children and adults with malignancies related to mutations to the cellular protein (RAS), which could be up to 30 percent of all cancers.
