SQ3370

Our assessment of immune changes after SQ3370 treatment confirms that observations in preclinical models are translatable to humans, as similar T-cell supportive immune changes were observed in syngeneic tumor models with SQ3370. Consistency between immune responses in clinical and preclinical samples underlines the translatability of the click chemistry-based drug and suggests that its broad therapeutic potential may be further enhanced with combined immunotherapies.

The lead candidate SQ3370 consists of an intratumorally (IT) injected tetrazine (Tz)-modified biopolymer and an intravenously (IV) administered trans-cyclooctene (TCO)-modified doxorubicin (Dox) protodrug. Anti-tumor activity was observed in multiple preclinical models for the TCO-MMAE protodrug in combination with both biopolymer and Fab targeting agents. These results highlight the power of click chemistry to activate a protodrug at the tumor site, independent of tumor biology, the molecular format or delivery method of the targeting agent.