AC710 Mesylate is a potent PDGFR inhibitor with dissociation constants (Kds) of 0.6 nM for FLT3, 1.57 nM for CSF1R, 1 nM for KIT, 1.3 nM for PDGFRα, and 1.0 nM for PDGFRβ.

FLT3:0.6 nM (kd), c-Kit:1 nM (kd), PDGFRβ:1 nM (kd), PDGFRα:1.3 nM (kd), CSF1R:1.57 nM (kd)

At a dosage of 0.3 mg/kg, AC710 temporarily inhibits tumor growth, which then quickly resumes. However, at dosages of 3 and 30 mg/kg, AC710 induces complete tumor regression, with the reduction in tumor volume remaining for an extended period post-treatment cessation. Furthermore, no loss of body weight is observed in AC710-treated animals across all dosages, suggesting good tolerability in mice. Efficacy of AC710 is also noted in a mouse collagen-induced arthritis (CIA) model, showing significant disease impact in a dose-dependent manner, with noticeable effects starting from a dosage as low as 3 mg/kg over a 15-day period (day 0-14). At higher doses (10 and 30 mg/kg), AC710 is as effective, if not more so, than dexamethasone in reducing joint swelling and inflammation when administered at a safe dose.

The antitumor efficacy of AC710 is assessed in a subcutaneous flank-tumor xenograft model in athymic nude mice using the MV4-11cell line. AC710 is dosed at 0.3, 3, and 30 mg/kg for 2 weeks. Tumor growth and body weight are monitored.