Targeted Therapy With CDK4/6 Inhibitors in Chemo-Refractory, Rb Wild-Type Extensive SCLC

Abemaciclib (CDK4/6 inhibitors) is an investigational drug that works by interrupting the rapid and uncontrolled growth of cancer cells. Some cancer cells develop because their cells overrun the molecular brakes that normally permit cell to divide only when they are needed to replace old ones. These brakes are regulated by a group of enzymes known as cyclin-dependent kinases (CDKs). Alterations causing over-activity of two of these enzymes, CDK4 andCDK6, are found in a variety of cancers, including small cell lung cancer with retinoblastoma (Rb) protein.The drugs work by selectively turning off the overactive CDK4 and CDK6. As a result, the cancer cells' division cycle is halted, preventing them from proliferating.