A small-molecule SUMOylation inhibitor activates antitumor immune responses and potentiates immune therapies in preclinical models.

SUMOylation, the covalent conjugation of small ubiquitin-like modifier (SUMO) proteins to protein substrates, has been reported to suppress type I interferon (IFN1) responses. TAK-981, a selective small-molecule inhibitor of SUMOylation, pharmacologically reactivates IFN1 signaling and immune responses against cancers. In vivo treatment of wild-type mice with TAK-981 up-regulated IFN1 gene expression in blood cells and splenocytes. Ex vivo treatment of mouse and human dendritic cells promoted their IFN1-dependent activation, and vaccination studies in mice demonstrated stimulation of antigen cross-presentation and T cell priming in vivo. TAK-981 also directly stimulated T cell activation, driving enhanced T cell sensitivity and response to antigen ex vivo. Consistent with these observations, TAK-981 inhibited growth of syngeneic A20 and MC38 tumors in mice, dependent upon IFN1 signaling and CD8+ T cells, and associated with increased intratumoral T and natural killer cell number and activation. Combination of TAK-981 with anti-PD1 or anti-CTLA4 antibodies improved the survival of mice bearing syngeneic CT26 and MC38 tumors. In conclusion, TAK-981 is a first-in-class SUMOylation inhibitor that promotes antitumor immune responses through activation of IFN1 signaling. TAK-981 is currently being studied in phase 1 clinical trials (NCT03648372, NCT04074330, NCT04776018, and NCT04381650) for the treatment of patients with solid tumors and lymphomas.

Pharmacological effects of TAK-828F: an orally available RORγt inverse agonist, in mouse colitis model and human blood cells of inflammatory bowel disease.

OBJECTIVE AND DESIGN: To evaluate the potency of RORγt blockade for treatment of Inflammatory Bowel Disease (IBD), the efficacy of TAK-828F, a novel RORγt inverse agonist, in anti-TNF-α mAb non-responsive mouse colitis model and effect of TAK-828F on IL-17 production in peripheral mononuclear blood cells (PBMCs) of anti-TNF-α naive and treatment-failure patients of IBD was investigated. METHODS AND RESULTS: The colitis model showed Th17-dependent pathogenicity and response to anti-IL-12/23p40 monoclonal antibody (mAb), but no response to anti-TNF-α mAb. In the model, TAK-828F, at oral dosages of 1 and 3 mg/kg, inhibited progression of colitis and reduced the immune reaction that characterize Th17 cells. Anti-IL-17A mAb showed neither efficacy nor change in the T cell population and colonic gene expression in the model. In the normal mouse, a 4-week treatment of TAK-828F at 30 mg/kg did not severely reduce lymphocyte cell counts in peripheral and intestinal mucosa, which was observed in RORγ-/- mice. TAK-828F strongly inhibited IL-17 gene expression with IC50 values from 21.4 to 34.4 nmol/L in PBMCs from anti-TNF mAb naive and treatment-failure patients of IBD. CONCLUSIONS: These results indicate that RORγt blockade would provide an effective approach for treating refractory patients with IBD by blocking IL-23/Th17 pathway.