The submission is expected to take place in the third quarter of 2014 based on discussions with the FDA regarding the final results of PALOMA-1, a randomized, Phase II trial comparing palbociclib plus letrozole versus letrozole alone in these patients.
In April 2013, the investigational oral targeted agent palbociclib received FDA Breakthrough Therapy designation for the first-line systemic treatment of women with advanced or metastatic ER+, HER2- breast cancer.
The FDA breakthrough therapy status was based on interim data from the PALOMA-1 trial.
The company said that palbociclib selectively inhibits cyclin-dependent kinases (CDKs) 4 and 6 to regain cell cycle control and block tumor cell proliferation.
Loss of cell cycle control is a hallmark of cancer and CDK 4/6 are overactivated in several cancers, leading to loss of proliferative control.
The trial is designed to evaluate progression-free survival in post-menopausal women with ER+, HER2- advanced breast cancer receiving palbociclib (125mg once daily for three out of four weeks in repeated cycles) in combination with letrozole versus letrozole alone (2.5mg once daily on a continuous regimen).
The PALOMA-1 trial is carried out in collaboration with the Jonsson Cancer Center’s Revlon/UCLA Women’s Cancer Research Program, led by Dr. Dennis Slamon.