The pediatric brain cancer known as diffuse intrinsic pontine glioma (DIPG) is almost uniformly fatal. In part, this is due to where and how it grows, forming as a diffuse net of cells in a part of the brainstem called the pons, which controls essential functions like breathing and swallowing. Another factor that makes DIPG especially dangerous is a lack of treatments — currently, there are no targeted therapies or immunotherapies proven effective to treat the condition, and the many chemotherapy clinical trials seeking to treat DIPG have been uniformly unsuccessful.

In fact, chemotherapy has been so unsuccessful against DIPG that researchers have questioned whether chemotherapy drugs are even able to reach the cancer. There is reason to believe they might not: Many drugs are unable to cross the blood-brain barrier that encapsulates the brain and central nervous system, and the pons is especially hard to reach. Now a study by University of Colorado Cancer Center researchers working at Children’s Hospital Colorado and published in the journal Neuro-Oncology Advances offers insight into this question.

«The results were surprising and encouraging,» says Adam Green, MD, CU Cancer Center investigator and pediatric brain cancer specialist at Children’s Hospital Colorado. «The bottom line is that it looks like the medicine does reach DIPG tissue in good quantities that have the potential to be effective against the tumor.»

In other words, the reason chemotherapy has been ineffective against DIPG is most likely the fact that we haven’t found the right chemotherapy yet.

In the clinical trial, done in collaboration with Michael Wempe, PhD, director of the Medical Chemistry Core Facility at the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, investigators gave one dose of the chemotherapy drug gemcitabine to newly diagnosed DIPG patients and then measured how much of this chemotherapy was present in patients’ tumor tissue on their biopsy performed immediately afterward. The group also performed parallel studies in mouse models of human DIPG. The results in humans and mice were similar, independent of exactly where the tumor grew in the brain, and held across a few known tumor subtypes.

«We don’t expect the one dose of chemo to be effective against the tumor, and so we were really asking families to take a leap of faith with us — to trust that it would be safe and that it would help answer an important question, both for their child and for future patients. To be the first family and patient was a really brave decision on their part,» Green says.

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Materials provided by University of Colorado Anschutz Medical Campus. Original written by Garth Sundem. Note: Content may be edited for style and length.