FLT3 / EGFR / ABL (also Fyn, Hck, Lck, Lyn, Ret, Yes)

Class

Oral multikinase inhibitor (INN: ruserontinib)

Pathway

Receptor and non-receptor tyrosine kinase signaling, particularly FLT3-driven AML signaling

This compound is an oral multikinase inhibitor designed to block several tyrosine kinases simultaneously, most notably FLT3, EGFR, and ABL, along with a set of Src-family kinases (Fyn, Hck, Lck, Lyn, Yes) and RET. Tyrosine kinases are enzymes that add phosphate groups to proteins, propagating growth and survival signals inside cells. FLT3 is a receptor expressed on early blood-forming cells; mutated, constitutively active forms of FLT3 are common drivers of acute myeloid leukemia (AML), making it a central target of this drug class. EGFR and ABL are kinases implicated in other cancers (epithelial tumors and chronic myeloid leukemia, respectively), and the Src-family kinases participate in signaling downstream of many receptors, including pathways leukemic cells use to survive when the primary driver is blocked. By inhibiting this broader panel rather than FLT3 alone, such a compound aims to suppress parallel or compensatory signaling routes that leukemic cells can exploit to escape single-target therapy, potentially offering more durable disease control. This multi-kinase strategy reflects a general principle in oncology: cancers driven by one dominant kinase often develop resistance through activation of related kinases, so agents with deliberately broad but rationally chosen selectivity can address multiple points of vulnerability at once.