Promising Drug Staves Off Cancer Worsening in Hormone Receptor-Positive Breast Cancer Patients

The gist: A drug called palbociclib may increase the amount of time that passes without cancer worsening for patients with advanced, estrogen receptor (ER)-positive, HER2-negative breast cancer. In a clinical trial, some patients were treated with palbociclib along with letrozole, and some were treated with letrozole alone. Patients who took both drugs went for twice as long without their cancer worsening than patients who took only letrozole. Learn more about palbociclib in breast cancer.

“In a groundbreaking study that offers new hope for women with advanced breast cancer, researchers from UCLA’s Jonsson Comprehensive Cancer Center have published final clinical trial results that showed the amount of time patients were on treatment without their cancer worsening (called progression-free survival) was effectively doubled in women with advanced breast cancer who took the experimental drug palbociclib.

“An investigational drug discovered and being developed by Pfizer Inc., palbociclib targets a key family of proteins (CDK4/6) responsible for cell growth by preventing them from dividing. Results of the multi-year phase 2 study showed a significant increase in PFS for patients with advanced breast cancer that was estrogen receptor positive (ER+), HER2-negative (HER2-), who were given a combination of the standard anti-estrogen treatment, letrozole, and palbociclib compared to letrozole alone.

” ‘We’re essentially putting the brakes on cell proliferation and causing these tumor cells to stop growing,’ said Dr. Richard Finn, associate professor of medicine at UCLA and lead author of the study.

“The study was published online ahead of print in the journal The Lancet Oncology.”