First-generation multi-kinase inhibitors like midostaurin and second-generation agents such as gilteritinib and quizartinib have shown success. It discusses how these agents, including small-molecule like STI-8591, compounds 36 and 80 and novel therapeutic strategies such as CLN-049, and SENTI-202, are designed to combat resistance. The goal is to provide a medicinal chemistry perspective to provide insights for the design of novel small-molecule FLT3i.