A novel family of disubstituted pyrido[3,4-b]pyrazine-based compounds was discovered as valuable series for the design of promising protein kinase inhibitors. SAR study allowed the identification of 4-(piperidin-1-yl)aniline moiety as pharmacophoric group, in C-5 or C-8 positions of the pyrido[3,4-b]pyrazine ring, for binding to the selected therapeutic targets. Several analogues were active at low micromomolar IC₅₀ values against a panel of seven cancer-related protein kinases providing an excellent starting point for further drug discovery optimization.