Definition

An orally bioavailable prodrug of SB1703, a small molecule inhibitor of high mobility group protein B1 (HMGB1), with potential immunomodulating and antineoplastic activities. Upon oral administration, SB17170 is converted to its active metabolite SB1703. SB1703 targets, binds to, and inhibits the activity of HMGB1. This inhibits HMGB1-mediated activation of immune-suppressive myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment (TME), thereby halting MDSC-mediated immunosuppression and enhancing T-cell-mediated anti-tumor immune responses. HMGB1, a damage-associated molecular pattern (DAMP) that acts as an immunomodulator, plays an important role in tumor cell proliferation, angiogenesis and metastasis.