Describing the development and first-in-human study of SQ3370, an intratumorally injected biopolymer paired with a doxorubicin payload, and the first in vivo click chemistry based therapeutic to be tested in humans. In the study, 12x the standard dose of doxorubicin was administered per cycle with mild and manageable toxicities, including less than anticipated myelosuppression. The lack of immunosuppression and high drug doses enabled T-cell-dependent immune responses, including cytotoxic CD8 + T-cell expansion and activation in tumors and systemically.
