Positive Phase III Results Ends Pfizer’s Ibrance Trial Early

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Pfizer announces that its Phase III trial for Ibrance met its primary endpoint and was ended early due to efficacy based on an assessment by an independent Data Monitoring Committee.


Pfizer announced on April 15, 2015 that its Phase III trial, PALOMA-3, for Ibrance (palbociclib) was ended early because it met its primary endpoint in improving progression-free survival (PFS) for the combination of Ibrance with fulvestrant. The trial compared fulvestrant with placebo in women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer following disease progression during or after endocrine therapy, according to a press release. The trial was ended early due to efficacy based on an assessment by an independent Data Monitoring Committee on the anti-cancer medicine with novel cyclin-dependent kinase 4/6 (CDK 4/6) inhibition.

“The results of this trial are especially important because they help us understand the potential of Ibrance to improve outcomes in patients with this difficult to treat cancer. We’re gratified to be able to stop the trial early and are engaging in discussions with health authorities regarding a regulatory path forward,” said Mace Rothenberg, MD, senior vice president of clinical development and medical affairs and chief medical officer for Pfizer Oncology, in a press release.


The drug received FDA Priority Review in October 2014 when in combination with letrozole, which reduces the amount of estrogen produced by the body. In February 2015, FDA granted accelerated approval of Ibrance in combination with letrozole for postmenopausal women with metastatic estrogen receptor positive, HER2- advanced breast cancer who are treatment naïve.

Source: Pfizer