Pfizer announces submission of Palbociclib NDA to FDA Pfizer announced it has completed the submission of a New Drug Application to the United States Food and Drug Administration for palbociclib. This NDA requests FDA approval of palbociclib, in combination with letrozole, for the treatment of postmenopausal women with estrogen receptor positive, human epidermal growth factor receptor 2 negative advanced breast cancer who have not received previous systemic treatment for their advanced disease. The submission is based on the final results of PALOMA-1, a randomized, Phase 2 trial comparing palbociclib plus letrozole versus letrozole alone in this population of patients. Palbociclib received Breakthrough Therapy designation from the FDA in April 2013, for the first-line systemic treatment of women with advanced or metastatic ER+, HER2- breast cancer. This designation was based on interim data from the PALOMA-1 trial. The FDA has a 60-day filing review period to determine whether the NDA is complete and acceptable for filing. Pfizer will communicate the Agency’s decision.