Palbociclib Doubles Survival in Women with Advanced Breast Cancer

the Cancer Therapy Advisor take:

According to a new study published online today in the journal The Lancet Oncology, researchers from Jonsson Comprehensive Cancer Center in Los Angeles, California, have found that palbociclib doubled progression-free survival in women with advanced breast cancer compared with those who did not receive the drug.

For the phase 2 study, researchers enrolled 165 post-menopausal women with advanced estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Patients received letrozole with or without palbociclib.

Results showed that progression-free survival was 20.2 months in the letrozole plus palbociclib arm versus 10.2 months in the letrozole only arm, corresponding with a 51% decreased risk of disease progression with palbociclib.

Furthermore, over 80% of those with metastatic estrogen receptor-positive disease experienced some benefit from the addition of palbociclib. In regard to safety, palbociclib caused leukopenia, but only to a manageable extent. Palbociclib prevents cancer cell proliferation by targeting CDK4/6 proteins, which are responsible for cell growth.

Palbociclib was granted Breakthrough Therapy Designation in 2013 by the U.S. Food and Drug Administration (FDA), and researchers are currently conducting an international phase 3 study in conjunction with Pfizer of palbociclib in 660 estrogen receptor-positive, HER2-negative advanced breast cancer.