Phase 1 study shows that Blaze Bioscience’s fluorescent mini-protein "lights up" tumors for surgeons.

Surgical removal of cancerous tumors, particularly brain tumors, can be quite challenging. Often it is difficult for surgeons to distinguish all of the cancerous cells from the healthy cells surrounding them.

Blaze Bioscience is trying to help with a product it is developing based on a protein that binds to tumor cells. Tozuleristide or BLZ-100 consists of a synthetic version of a mini-proten isolated from the deathstalker scorpion that binds to cancer cells, but not to healthy tissue, attached to a fluorescent dye that emits near-infrared light. The hope is that once applied, the “tumor paint” can “light up” a tumor, allowing surgeons to remove more of the cancerous material without harming healthy tissue.

The company has received its first encouraging results from a phase 1 study involving 17 patients at Cedars-Sinai Medical Center in Los Angeles and the Newro Foundation in Brisbane, Australia with new or recurrent gliomas. The patients received a 3 mg to 30 mg dose of BLZ-100 3 to 29 hours prior to tumor resection surgery. Three different imaging systems were used to look at each tumor prior to surgery and each cavity left behind after surgery. 

In all cases, the tumors were visible to some degree due to treatment with BLZ-100. High-grade (faster growing and spreading) tumors exhibited the most intense fluorescence, and the intensity for all tumors increased as the dose increased. No side effects or dose-limiting toxicity were observed. According to the company, these results suggest that tozuleristide imaging may be useful for [fluorescence-guided surgery] of glioma and indicate that further clinical trials are warranted.

The initial study also revealed the need for better imaging systems for use in brain cancer surgery and led to the development of the Canvas Imaging System, which is being used in a pivotal trial that was initiated in November 2018. The company hopes to enroll a total of 114 children with primary central nervous system tumors at 15 U.S. sites that are part of the Pacific Pediatric Neuro-Oncology Consortium.