Palbociclib is in clinical development for treatment of women with high-risk early breast cancer, as a treatment after main cancer treatment to reduce cancer cell spread. Women are classified as high-risk if they have a greater than 30% chance of developing breast cancer in their lifetime, this is a result of number of physiological and environmental factors, such as age. Early breast cancer is where the disease is limited to the breast region and has not spread to other parts of the body.
Palbociclib is an oral cancer medicine. It works by blocking the activity of certain enzymes known as cyclin-dependant kinases (CDK) 4 and 6, which play a key role in regulating the way cells grow and divide. By blocking these enzymes, palbociclib slows the growth of breast cancer cells, and has been shown to be tolerable to patients over an extended period of time. If licenced, palbociclib will provide an additional treatment option for adults with invasive early breast cancer.