DDR1-IN-4 (Compound 2.45) is a highly potent inhibitor that selectively targets Discoidin Domain Receptor 1 (DDR1) autophosphorylation. This compound demonstrates exceptional efficacy with IC50 values of 29 nM and 1.9 μM for DDR1 and DDR2, respectively.

DDR1-IN-4 (Compound 2.45) demonstrates a dose-dependent suppression of DDR1 phosphorylation in HT1080 cells with DDR1 overexpression, achieving over 70% inhibition at 1 μM concentration, while maintaining selectivity against DDR2 [1].

DDR1-IN-4 (Compound 2.45, ip, 90 mg/kg) effectively maintains renal function and mitigates tissue damage in Col4a3 –/– mice, serving as a preclinical model for Alport syndrome, by implementing a therapeutic dose regimen. This demonstrates the potential benefits of targeting DDR1 phosphorylation inhibition in vivo[1]. In this Col4a3 –/– mouse model, depicting Alport syndrome[1], administration of 90 mg/kg via intraperitoneal injection daily notably decreased fibrosis, evident from assessments using Picro Sirius Red, smooth muscle actin staining, and collagen I levels. Additionally, there was a considerable reduction in pDDR1 levels in these mice compared to control groups, underlining the compound's efficacy.