A Real-World Experience Of Palbociclib-Induced Adverse Events In Women With Hr-Positive/Her2-Negative Metastatic Breast Cancer.

e13061Background: Palbociclib is a novel small molecule inhibitor of cyclin dependant kinases 4 and 6, and has been shown to improve progression free survival in HR positive metastatic breast cancer patients when used in conjunction other endocrine therapies, with a manageable safety profile. The aim of our study was to provide a real world experience of the adverse events (AEs) reported on this treatment. Methods: We performed a retrospective, single centre audit of HR positive metastatic breast cancer patients treated with Palbociclib over a six month period in an Irish tertiary hospital. Results: 64 patients were included in the analysis. Median age was 62.5 years. Palbociclib was most commonly used in combination with Letrozole (n = 40). 10 patients received Palbociclib as 1st line treatment. The median number of cycles completed was 5 (range 1-9). 28 patients (44%) had treatment deferrals due to neutropenia, with a median time to first deferral of 4 weeks. Only one patient developed febrile neutropen...