New breast cancer drug may have ‘powerful effect’ against other types of cancer

A new oral drug effective in fighting breast cancer has been found to have a potential in treating patients with other types of cancer. A new study shows that the drug palbociclib could deliver a more powerful effect when combined with other anti-cancer therapies to prevent rapid cancer-cell division and tumour growth.

A review of 130 publications and a study by researchers from the University of Pennsylvania, published in JAMA Oncology, show that palbociclib has delivered minor effects on normal cells, while it caused shrinkage and prevented the growth of tumours. The drug mainly works to prevent the rapid division of tumour cells.

Palbociclib reduces the activity of the enzymes CDK4 and CDK6, which can boost cell division. The drug is the first CDK4/6 inhibitor to be approved to treat breast cancer.

"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," said lead author Dr Amy Clark, an assistant professor of Hematology/Oncology at Penn's Perelman School of Medicine and ACC. "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."

However, the researchers noted that palbociclib caused reversible neutropenia, an abnormal low count of neutrophils, a type of white blood cell that fights infections, which led the trials to temporarily discontinue and reintroduce the drug at a lower dose to avoid the side effect. Other side effects include fatigue, nausea, diarrhea, constipation and rash.

Meanwhile, results of the trials also show that the drug has the potential to effectively treat lymphoma, sarcoma and teratoma. In trials in breast cancer and other types, the drug has been found to be safe with once-daily dosing.