Blz-100 Provides Optical Contrast In Animal Models Of Breast Cancer

Over 230,000 new breast cancer cases occur in the US annually. Complete surgical removal of tumor tissue is critical to reduce the risk of local recurrence. About 24% of patients who undergo breast conservation surgery require a second surgery due to positive margins. Second surgeries can be psychologically and financially costly to patients. BLZ-100, a peptide-fluorophore conjugate, is a Tumor Paint product candidate being developed to provide real-time, high resolution, intraoperative optical contrast between tumor and normal tissue, potentially helping surgeons accomplish more complete and accurate tumor resections. Intraoperative imaging with BLZ-100 may potentially improve the percentage of breast cancer patients achieving a complete resection and negative margins at their first surgical procedure. To better define the relationship between tumor pathology and BLZ-100 fluorescence, data from mouse models and canine mammary cancer cases were evaluated. Human breast cancer was modeled in mice using cell lines and xenograft models using patient-derived tumors. Review of histopathology was also conducted for each dog case. Animals received a single IV dose of BLZ-100, and tumors were excised one day after dosing. Excised tumor and normal tissues were imaged using the Odyssey Clx (LI-COR) to determine the ratio of signal in tumor compared to normal (background) tissue (TBR). Detailed histopathology reports for the dog cases were also analyzed to determine factors potentially associated with fluorescence intensity and TBR. A significant BLZ-100 TBR was observed. Histopathologic features potentially associated with TBR in dogs included cellularity and the degree of infiltration and demarcation. The studies supported the concept that BLZ-100 might potentially serve as an intraoperative optical imaging agent for breast cancer surgery. Citation Format: Stacey Hansen, Janean Fidel, Katie Kennedy, William Dernell, Boel Fransson, Josh Ramsay, Valorie Wiss, Mark Stroud, Julia E. Parrish-Novak. BLZ-100 provides optical contrast in animal models of breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4245.