XH-30002

XH-30002 (also known as JRF104) is a selective small molecule inhibitor of cyclin-dependent kinase 4 (CDK4) currently under development by Jinrui Foundation for the treatment of advanced solid tumors. Unlike first-generation CDK4/6 inhibitors, XH-30002 is designed to selectively target CDK4 while sparing CDK6, a strategy intended to reduce hematological toxicities such as neutropenia that are commonly associated with CDK6 inhibition in the bone marrow. By inhibiting CDK4, the drug prevents the phosphorylation of the retinoblastoma (Rb) protein, thereby arresting the cell cycle in the G1 phase and inhibiting tumor cell proliferation. It is currently being evaluated in Phase 1 clinical trials to assess its safety, pharmacokinetics, and preliminary anti-tumor activity.