CDK2/4/6/CDK4

Class

small molecule

Notes

original target text: CDK2/4/6/CDK4 inhibitor

Cyclin-dependent kinases (CDKs) are enzymes that, together with partner proteins called cyclins, drive cells through the division cycle. CDK4 and CDK6, paired with cyclin D, phosphorylate the retinoblastoma protein (Rb), releasing transcription factors that switch on genes needed to enter the DNA-synthesis (S) phase. CDK2, paired with cyclin E, reinforces this same transition and helps commit the cell irreversibly to division. Many cancers hijack this pathway, either by amplifying the cyclins that activate these kinases or by losing the brakes that normally restrain them, leading to unchecked proliferation. Selectively inhibiting CDK4/6 has become a common strategy, but tumors frequently escape by upregulating cyclin E and driving proliferation through CDK2 instead. A compound that inhibits CDK2, CDK4, and CDK6 together aims to close that escape route, blocking the cell cycle at more than one point rather than relying on a single vulnerable node. This mechanism is broadly relevant wherever cell cycle control is disrupted, most prominently in hormone-driven and other proliferative cancers, and combined CDK2/4/6 inhibition is of particular interest for tumors that are resistant to selective CDK4/6 blockade.