Hormone receptor positive (HR+) breast cancer (BC) represents the largest therapeutic subtype of the disease, accounting for 60 to 65% of all malignant neoplasms of the breast. Palbociclib (Ibrance®) is a small-molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6) which in clinical trial settings has been shown to increase progression-free survival (PFS) for patients with HR+, human epidermal growth factor 2-negative (HER2-) metastatic breast cancer (MBC). Palbociclib first received a European Union (EU) marketing authorisation in September 2016, to be commercialised as Ibrance® by Pfizer. Palbociclib was recommended for use with an aromatase inhibitor in patients with HR+/HER2- locally advanced and MBC in the National Health Service (NHS) in England by the National Institute for Health and Care Excellence (NICE) in November 2017 and by the Scottish Medicines Consortium (SMC) in December 2017. In order to provide access to palbociclib in the United Kingdom (UK) during the NICE/SMC appraisal period, the Ibrance® Patient Program (IPP) was initiated and run by Pfizer between April 2017 until a positive NICE/SMC appraisal in November 2017 (for England and Wales) or December 2017 (for Scotland).~Pfizer are interested in the opportunity to collect data from patients who received palbociclib as part of the UK IPP, to better understand patients' characteristics in a routine care setting, treatment persistence and dose management, clinical outcomes, and healthcare resource utilisation. This study will provide real-world evidence on patients' clinical progression and experience of treatment with palbociclib in routine clinical settings in a UK context.~Research question:~What are the real-world treatment patterns, patients' characteristics, clinical outcomes and healthcare resource utilisation associated with palbociclib treatment in the 3 years following initiation in United Kingdom patients with HR+/HER2- MBC treated as part of the IPP?
What are the real-world treatment patterns, patients' characteristics, clinical outcomes and healthcare resource utilisation associated with palbociclib treatment in the 3 years following initiation in United Kingdom patients with hormone receptor-positive, human epidermal growth factor 2-negative metastatic breast cancer treated as part of the IPP?