RET

Class

RET inhibitor (oral small molecule capsule)

Pathway

inhibits oncogenic RET fusion/mutation-driven kinase signaling

RET (rearranged during transfection) is a receptor tyrosine kinase, a cell-surface protein that receives signals and activates internal signaling cascades that drive cell growth and survival. Normally RET activity is tightly controlled by binding of specific growth factors. In certain cancers, genetic alterations—chromosomal rearrangements that fuse RET to another gene (RET fusions) or point mutations within the RET gene—cause the kinase to signal continuously without normal control, functioning as an oncogenic driver that pushes cells toward uncontrolled proliferation. Small-molecule RET inhibitors are designed to fit into the kinase's active site and block this constitutive signaling, aiming to selectively suppress growth of tumor cells that depend on aberrant RET activity while sparing cells that do not. This approach falls under the broader strategy of targeted cancer therapy, in which a drug is matched to the specific genetic alteration identified in a patient's tumor rather than treating all tumors of a given organ the same way. RET alterations are found across several cancer types, including certain lung and thyroid cancers, making RET a recurring oncogenic driver relevant to precision oncology broadly, independent of the tissue of origin.