SQL70

SQL70 is a tetrazine-modified hyaluronic acid-based biopolymer developed by Shasqi, Inc., as the tumor-localizing component of the SQ3370 therapeutic system. It is designed to be injected intratumorally, where it remains localized and serves as a click chemistry activator. When the system's second component, the intravenously administered doxorubicin protodrug SQP33, reaches the tumor site, it undergoes a rapid and selective tetrazine-trans-cyclooctene click chemistry reaction with SQL70. This reaction triggers the release of active doxorubicin specifically within the tumor microenvironment, thereby increasing local drug concentration while minimizing systemic toxicity. SQL70 is part of the Click Activated Protodrugs Against Cancer (CAPAC) platform and has been evaluated in Phase 1/2 clinical trials for advanced solid tumors, including soft tissue sarcoma and head and neck cancer.