Blaze Bioscience, a company working on a fluorescent molecule to help surgeons better remove tumors, reported data from a phase 1 trial testing its “tumor paint” in adults with gliomas, a type of brain cancer.
The tumor paint is based on a miniprotein found in the deathstalker scorpion that binds to cancer cells, but not to healthy tissue, said Blaze Bioscience co-founder Jim Olson, M.D., a pediatric neuro-oncologist at the Fred Hutchinson Cancer Research Center and Seattle Children’s Hospital, in a video. Blaze has attached a fluorescent dye—what Olson calls little molecular flashlights—to a synthesized version of this protein to create the tumor paint, which zeroes in on tumors and emits near-infrared light. The hope is that lighting up the tumors will help surgeons remove more of a tumor without sacrificing normal tissue.
The phase 1 study enrolled 17 patients with new or recurrent gliomas at Cedars-Sinai Medical Center in Los Angeles and the Newro Foundation in Brisbane, Australia. The patients received a dose of the tumor paint, called tozuleristide or BLZ-100, between 3 mg and 30 mg. They then underwent tumor resection surgery three to 29 hours later. The investigators used three different imaging systems to look at the tumor before surgery and the cavity left behind after surgery.
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Tozuleristide lit up tumors of varying grades, with high-grade tumors—which tend to grow and spread faster than low-grade tumors—showing more intense fluorescence than low-grade tumors. The intensity of the fluorescence increased as the dose increased. No patients experienced side effects that “were considered related to tozuleristide,” and the study did not reach any dose-limiting toxicity—meaning the investigators didn’t see any side effects that would preclude trying a higher dose. The findings appear in Neurosurgery Now.
“These results support the safety of tozuleristide at doses up to 30 mg and suggest that tozuleristide imaging may be useful for [fluorescence-guided surgery] of gliomas,” the investigators concluded.
“Based on these encouraging results, further clinical trials are definitely warranted,” said senior author Adam Mamelak, M.D., a neurosurgeon at Cedars-Sinai, in a statement.
Although the researchers used commercially available imaging systems to detect fluorescence, Blaze is working on its own device, dubbed the Canvas Imaging System.
“The study also pointed out the need for improved imaging devices for brain cancer surgery applications which led to the development of the Canvas Imaging System being used in our ongoing pivotal study,” said Dennis Miller, Ph.D., the senior vice president of development at Blaze Bioscience.
That pivotal study kicked off last November and aims to enroll 114 children with primary central nervous system tumors. The first patient was enrolled in Blaze’s native Seattle, but the trial is taking place at 15 U.S. sites that are part of the Pacific Pediatric Neuro-Oncology Consortium.