Comprehensive Report on Tozuleristide (BLZ-100): An Investigational Agent for Fluorescence-Guided Surgery

I. Executive Summary

Tozuleristide, also known by its investigational code BLZ-100, is a novel, first-in-class, injectable imaging agent under development by the privately held biotechnology company Blaze Bioscience, Inc. It is classified as a biotech product, specifically a peptide-dye conjugate, designed to provide real-time, intraoperative visualization of malignant tissue. The agent's structure comprises two key components: a synthetic variant of chlorotoxin (CTX), a peptide derived from scorpion venom that provides tumor-targeting specificity, and indocyanine green (ICG), a near-infrared (NIR) fluorescent dye that allows for tissue illumination. This dual-component design forms the basis of the company's "Tumor Paint®" platform technology.

The mechanism of action relies on the CTX moiety's ability to selectively bind to a constellation of proteins often overexpressed in the tumor microenvironment, including matrix metalloproteinase-2 (MMP-2) and neuropilin-1 (NRP1). This targeted binding leads to the accumulation and retention of Tozuleristide within cancerous tissue. Upon excitation with a compatible NIR imaging system, the ICG component fluoresces, enabling surgeons to visually differentiate tumor margins from surrounding healthy tissue with high precision.

Clinical development has demonstrated a favorable safety and tolerability profile across multiple Phase 1 trials in adults with glioma, skin cancer, and sarcoma, as well as in pediatric patients with central nervous system (CNS) tumors. A maximum tolerated dose has not been identified, and adverse events have been minimal. Pharmacokinetic studies reveal a short serum half-life, yet prolonged tumor fluorescence, providing strong evidence of specific target engagement and retention.