Efficacy of Palbociclib + Letrozole Examined in Metastatic Breast CA
HealthDay News — Palbociclib can help slow the progression of advanced breast cancer, according to a study published in the November 17 issue of the New England Journal of Medicine.
Richard Finn, MD, an assistant professor of medicine at the University of California, Los Angeles, and colleagues tested palbociclib-letrozole as a first-line treatment for estrogen-receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. They randomly assigned 666 women to receive the drug combination or letrozole alone, and followed them for up to three years.
At that point, the researchers found that 43.7% of women in the palbociclib group had either died or seen their cancer progress. That compared with 61.7% of women on letrozole alone. Women on the drug combination typically remained progression-free for 24.8 months, versus 14.5 months for women on letrozole. One of the most common side effects – seen in two-thirds of women in this study – was neutropenia.
"Among patients with previously untreated ER-positive, HER2-negative advanced breast cancer, palbociclib combined with letrozole resulted in significantly longer progression-free survival than that with letrozole alone, although the rates of myelotoxic effects were higher with palbociclib-letrozole," the authors conclude.
The study was funded by Pfizer, the manufacturer of palbociclib.