The objective of this study is to describe patient demographics, clinical characteristics, treatment patterns and clinical outcomes of adult female patients who have received palbociclib combination treatments as first line therapy, regardless of combination partner and labelled use in real world settings across Brazil.

The primary objective of this real world study is to describe patient demographics, clinical characteristics, treatment patterns and clinical outcomes of adult female patients who have received palbociclib combination treatments as first line therapy, regardless of combination partner and labelled use.

Primary Objectives

• To describe the demographic and clinical characteristics of patients who have received palbociclib combination treatments in line with locally approved indications.

• To describe adjuvant therapies received for their treatment of early or locally advanced breast cancer (Stages 0-IIIa).

• To describe treatments received in the advanced/metastatic setting, before and after palbociclib combination use.

• To describe dosing and dose changes, interruptions, delays, and discontinuations associated with palbociclib use in clinical practice.

• To describe supportive therapies received by patients while receiving palbociclib combination treatments.

• To determine the following outcome in overall population and defined subgroups for patients who had received palbociclib combination treatment for at least 6 months:

  • Progression-free survival;
  • Objective response rate (ORR);
  • Proportion of patients alive.

Exploratory Objectives

• To evaluate progression-free survival (PFS) associated with palbociclib combination treatments after 1 and 2 years following Palbociclib combination treatment.

This study will be conducted as a retrospective medical record review of patients who have received palbociclib combination treatments as first line treatment regardless of combination. The study will comprise of a medical record review conducted in Brazil. The study design is similar to a previously conducted RWE IRIS Global study previously conducted in multiple other countries (protocol no. A5481090) .

Data collection will be online via electronic data capture using electronic case report form (eCRF). Each physician will be asked to select all the medical records of approximately 5-20 patients per site (approximate total: 300 patients) who meet the inclusion criteria and then invited to complete the eCRF from each enrolled patient. Time to complete each eCRF will be 30 minutes, approximately.

In order to allow for a sufficiently long observational window, physicians will be asked to go back to a specific point in time, the index date, and sequentially select the medical records of the next 'n' patients who meet the inclusion criteria. The 'index date' will be defined as 30 days after the physician first prescribed palbociclib + partner therapy following the approval of the indication in Brazil (eg, if palbociclib + letrozole was available Feb 1, 2018 in Brazil and the physician initiated a patient on palbociclib+ letrozole the next day, the index date will be April 2, 2018).

The advantage to a retrospective medical record review approach over a database analysis is that of being designed specifically to collect data that fulfils the study objectives. Thus, it readily collects and informs on all key drug related clinical outcome measures of critical importance to this study, in a consistent manner, across countries if reported in a medical record. The resulting data set enables direct comparisons across markets, delivering in turn greater confidence in the reliability of conclusions drawn from the research. An additional advantage of this approach lies in the ability to obtain information that only the treating physician may be aware of, such as the reasons for treatment switches or discontinuations or more perceptive questions that rely on the physician's professional opinion.

Inclusion Criteria:

• HR+/HER2- breast cancer diagnosis with confirmed ABC/MBC
• Received palbociclib as a first line therapy
• No prior or current enrolment in an interventional clinical trial for ABC/MBC
• Have a potential follow-up period of 6 months following the index date (30 days after first palbociclib prescription: palbociclib with fulvestrant and/or palbociclib with letrozole/aromatase inhibitor).

Exclusion Criteria:

• Patients who were enrolled to receive fulvestrant but already received previous therapies

Female participants only

Adult female patients with HR+/HER2 non-metastatic breast cancer who progressed to locally advanced (stage IIIB/C) or metastatic (stage IV) breast cancer receiving palbociclib combination regimens as per the approved indication.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.