HPK1-IN-69

HPK1-IN-69 is an orally active HPK1 inhibitor with an IC50 of 1.7 nM. It inhibits the HPK1-mediated TCR signaling pathway, reduces phosphorylation levels of SLP76, and promotes the release of IL-2. In mouse models, HPK1-IN-69 exhibits in vivo antitumor activity. This compound is applicable for research on colorectal cancer and MC38 syngeneic tumors.

HPK1-IN-69 (compound 53) demonstrates dose-dependent inhibition of CD3/CD28-induced SLP76 phosphorylation in Jurkat T cells, with an IC50 for pSLP76 of 23.1 nM following a 2-hour pre-incubation at concentrations ranging from 0 to 300 nM. At concentrations from 0 to 1000 nM with a 1-hour pre-incubation, HPK1-IN-69 also enhances CD3/CD28-induced IL-2 release in Jurkat T cells (EC50 = 29.9 nM) and hPBMCs and can reverse PGE2-mediated IL-2 suppression. The compound shows good metabolic stability in mouse and human liver microsomes, with a half-life exceeding 30 minutes over a 0 to 60-minute period. It exhibits weak inhibitory effects on human CYP isoenzymes, with IC50 values ranging from 6.1 μM to greater than 50 μM, indicating a specific safety window regarding CYP interactions. The inhibition activity on the hERG channel is relatively low, with an IC50 of 7.92 μM, suggesting a low risk of cardiotoxicity.

HPK1-IN-69, administered at 15-30 mg/kg via intraperitoneal injection twice daily for 17 days, exhibits a dose-dependent antitumor effect in the CT26 colorectal cancer mouse model. In the MC38 colorectal cancer mouse model, HPK1-IN-69, administered at 15-60 mg/kg either intraperitoneally or orally twice daily for 21 days, demonstrates significant antitumor efficacy, achieving a 64% tumor growth inhibition (TGI) at an oral dose of 60 mg/kg. Furthermore, when combined with an anti-PD-1 antibody, it shows a synergistic activity, achieving a TGI of 77%.