Posted by on Dec 13, 2015 in Breast cancer | 0 comments

In a nutshell

This study examined the effectiveness of palbociclib (Ibrance) in the treatment of hormone receptor-positive breast cancer patients. The authors found that palbociclib treatment increased progression free survival.

Some background

Major treatment options for hormone receptor-positive (HR+, dependent on the hormones estrogen and/or progesterone for growth) breast cancers are therapies that block the effects of estrogen. In some women, though, the cancer progresses despite hormone therapy. While anti-estrogen drugs, such as fulvestrant (Faslodex), have been found to be helpful for progressive cancer, additional treatments are often needed.

Palbociclib is a new treatment that blocks cancer cell growth. Palbociclib received accelerated approval by the U.S. Food and Drug Administration (FDA) in September 2015. Preliminary phase 2 studies have shown that the combination of palbociclib and the anti-estrogen letrozole (Femara) led to longer progression-free survival (time from treatment until disease progression). Large late-phase trials are currently underway to confirm the effectives and safety of palbociclib.

Methods & findings

The study examined the effectiveness of palbociclib in combination with fulvestrant in breast cancer patients who progressed despite prior hormone therapy. 521 patients with HR+, HER2-negative (not dependent on HER2 for growth) breast cancer were included in this study. 347 patients received palbociclib and fulvestrant, while 173 received a placebo and fulvestrant. Both pre- and post-menopausal women were included in this study.

Average progression-free survival for patients treated with palbociclib was 9.2 months, compared to 3.8 months for those treated with placebo. Time to progression was similar for both pre- and post-menopausal women.

The most common adverse (negative) effects for those treated with palbociclib included low white blood cell levels (25.2%-62%), fatigue (2.0%) and anemia (low red blood cell levels, 2.6%).

The bottom line

This study concluded that a combination of palbociclib and fulvestrant led to longer progression-free survival in advanced progressive HR+ breast cancer patients.

The fine print

This study was funded by Pfizer, the manufacturers of palbociclib.

Published By :

The New England Journal of Medicine

Date :

Jun 01, 2015

Original Title :

Palbociclib in Hormone-Receptor-Positive Advanced Breast Cancer.

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