A new oral drug, palbociclib, which has shown efficacy in fighting breast cancer alone and in combination with endocrine therapy, also has the potential to combat other types of cancer, according to a literature review and research released by experts at the University of Pennsylvania.
Palbociclib targets rapidly dividing tumor cells by blocking the activity of the enzymes CDK4 and CDK6, which stimulate cell division and show an increase in numbers in most cancers; it is also the first CDK4/6 inhibitor to be approved to breast cancer treatment.
"All living cells undergo cell division and palbociclib's unique capacity to halt the cell division process (also known as the 'cell cycle') therefore has potentially broad applicability," Amy Clark, lead author of the study, said in a press release. "Pairing palbociclib with other anti-cancer therapies such as endocrine therapy, chemotherapy, and targeted therapy can create a powerful combinatorial effect with real promise for addressing a variety of cancers."
For example, the increase in CDK4 activity has been seen in a high number of melanomas and esophageal cancers, leading scientists to believe that in combination with targeted therapy, palbociclib can be used to effectively identify and attack cancer cells without harming normal cells.
"This drug has minor effects on normal cells other than neutrophils (white blood cells)," said Peter O'Dwyer, senior author of the study. "In tumors, it can cause shrinkage, or more commonly, arrest of growth. As we discover new functions for the CDK4/6 target of this medicine, we are likely to use it in combinations to make other anti-cancer agents work better."
The researchers conducted a literature review of 130 relevant publications and combined this information with their own current research – they found that palbociclib has a high level of safety and effectiveness in fighting certain types of breast cancer and shows promise in early trials against lymphoma, sarcoma, and the rare teratoma tumors that typically effect younger patients.
The study was published in the Dec. 3 issue of JAMA Oncology.
