UK Ibrance Patient Program (IPP) Study

Study Overview
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Brief Summary
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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?

Detailed Description
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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?

Official Title
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Observational Cohort Study of Patients With Hormone Receptor-positive Metastatic Breast Cancer Treated With Palbociclib (Ibrance(Registered)) as Part of the United Kingdom Ibrance (Registered) Patient Program (IPP); the Real Outcomes Ibrance (Registered) Study (ROIS)

Conditions
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HR+/HER2- Locally Advanced, Metastatic Breast Cancer

Intervention / Treatment
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* Drug: Palbociclib


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: All patients meeting the following eligibility criteria will be included in the study: Patients enrolled into the IPP at one of the selected hospitals (see Annex 1 for IPP enrolment letter). Patients who received ≥1 dose of palbociclib as part of the IPP at one of the selected sites. For sites where data collection is performed by pH Associates, written informed consent will be required from living patients to access their medical records. Patient aged ≥18 years old at enrollment into the IPP

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Palbociclib|Palbociclib|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants According to Treatment Lines | Percentage of participants according to treatment lines during anytime between breast cancer (BC) diagnosis and index date were reported in this outcome measure. Treatment lines included: 1) 1st line where, palbociclib was prescribed as the first line treatment for MBC, 2) 1st line palbociclib added to letrozole where, palbociclib was prescribed as the first line treatment along with ongoing letrozole treatment which was prescribed more than 3 months prior to initiation of palbociclib, 3) 2nd line where palbociclib was prescribed as the second or later treatment line for MBC. | At baseline | 
| Time From Letrozole to Palbociclib Initiation | Time from letrozole was defined as duration from the start date of letrozole which was ongoing at the time of palbociclib treatment initiation up to the index date. | At baseline | 
| Number of Participants With Menopausal Status | Number of participants with menopausal status as pre-menopausal, peri-menopausal, post-menopausal and not applicable (NA), during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants According to Disease Free Interval at Palbociclib Initiation | Disease free interval was defined as the time from the date of last known neo-adjuvant hormone therapy to the date of MBC diagnosis. | At baseline | 
| Percentage of Participants With Primary or Recurrent Metastatic Breast Cancer Diagnosis | Percentage of participants with de novo and recurrent metastatic disease, during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants With Lymph Nodes Involvement | Percentage of participants with lymph nodes involvement during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. Data for this outcome measure is also presented by de novo status. | At baseline | 
| Number of Lymph Nodes Involved | Number of lymph nodes involved during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. Data for this outcome measure is also presented by de novo status. | At baseline | 
| Number of Participants With Estrogen, Progesterone and Human Epidermal Growth Factor 2 (HER2) Receptor Status | Number of participants with estrogen, progesterone and HER2 receptor status during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants Who Had Rebiopsy After Metastatic Disease Diagnosis | Percentage of participants who had rebiopsy during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants According to Tumor Stage | Percentage of participants with tumor stages 0, 1, 2, 3 and 4, as per Tumor, Node, Metastasis (TNM) staging system, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. As per TNM staging system, tumor stage 0 indicates main tumor cannot be found; tumor stages 1, 2, 3 and 4 refers to the size and/or extent of the main tumor. The higher the number, the larger the tumor and/or the more it has spread into nearby tissues. Data for this outcome measure is also presented by de novo status. | At baseline | 
| Percentage of Participants According to Nodal Status | Percentage of participants with nodal stages 0, 1, 2 and 3, as per TNM staging system, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. As per TNM staging system, nodal stage 0 indicates no cancer in regional lymph nodes; nodal stages 1= cancer has spread to 1 to 3 lymph nodes; nodal stage 2= cancer has spread to 4 to 9 lymph nodes, nodal stage 3= indicates the cancer has spread to 10 or more lymph nodes. Data for this outcome measure is also presented by de novo status. | At baseline | 
| Percentage of Participants According to Metastasis | Percentage of participants with metastasis stages 0 and 1, as per TNM staging system, during anytime between MBC disease diagnosis and index date were reported in this outcome measure. As per TNM staging system, metastasis stage 0 indicates cancer has not spread to other parts of the body; metastasis stage 1 indicates that the cancer has spread to distant parts of the body. Data for this outcome measure is also presented by de novo status. | At baseline | 
| Tumor Size at Palbociclib Initiation |  | At baseline | 
| Percentage of Participants According to Tumor Grade | Percentage of participants with tumor grades, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. Grades of disease was classified as grades 1, 2 and 3. As per TNM system, grade 1= well differentiated cells, low grade; grade 2= moderately differentiated cells, intermediate grade and grade 3= poorly differentiated cells, high grade. | At baseline | 
| Percentage of Participants With Ki-67 Protein Proliferation Index Recorded | Percentage of participants with Ki-67 protein proliferation index during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. The Ki-67 protein is a cellular marker for proliferation. Ki-67 is a protein in cells that increases as cells prepare to divide into new cells. A staining process can measure the percentage of tumor cells that are positive for Ki-67. More positive cells hasten in dividing and forming new cells. Proliferation index was measured by the percentage of cells staining for Ki-67. | At baseline | 
| Ki-67 Protein Proliferation Index | The Ki-67 protein is a cellular marker for proliferation. Ki-67 is a protein in cells that increases as cells prepare to divide into new cells. A staining process can measure the percentage of tumor cells that are positive for Ki-67. More positive cells hasten in dividing and forming new cells. Proliferation index was measured by the percentage of cells staining for Ki-67. | At baseline | 
| Percentage of Participants With Eastern Cooperative Oncology Group Performance Score (ECOG PS) | ECOG PS measured quality of life of cancer participants on a 0 to 5 scale; 0= fully active, able to carry on all pre-disease performance without restriction; 1= restricted in physically strenuous activity, ambulatory, able to carry out light/sedentary work; 2= ambulatory, capable of all self-care, unable to carry out any work activity, up >50 % of waking hours; 3= capable of only limited self-care, confined to bed/ chair >50% of waking hours; 4= completely disabled, cannot carry on any self-care, totally confined to bed or chair; 5= dead. Higher scores indicated worsening of quality of life. | At baseline | 
| Percentage of Participants With Recurrence Type | Percentage of participants with recurrence type during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants According to Number of Metastatic Sites | Percentage of participants according to number of metastatic sites during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants According to Location of Metastases | Percentage of participants according to location of metastases, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants With Non-Visceral Location of Metastases | Percentage of participants with non-visceral location of metastases, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Participants According to Metastatic Sites With Locoregional Recurrence | Number of participants according to metastatic sites with locoregional recurrence, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. Metastatic sites with locoregional recurrence included bone, breast, lung, pleural, regional lymph nodes and other sites. | At baseline | 
| Duration of Disease at Initiation of Palbociclib | Duration of BC disease was the time duration between date of BC disease diagnosis to palbociclib treatment initiation date. | At baseline | 
| Percentage of Participants Who Received Chemotherapy in Adjuvant or Neoadjuvant Setting | Percentage of participants who received chemotherapy in adjuvant or neoadjuvant setting, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants Who Received Chemotherapy in Advanced, Disease Modifying or Metastatic Setting | Percentage of participants who received chemotherapy in advanced, disease modifying or metastatic setting, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Lines of Prior Chemotherapy for Metastatic Disease | Number of lines of prior chemotherapy for metastatic disease during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants Who Received Luteinizing Hormone Releasing Hormone (LHRH) or Chemotherapy | Percentage of participants who received LHRH or chemotherapy, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants Who Received Endocrine Therapy in Adjuvant or Neoadjuvant Setting | Percentage of participants who received endocrine therapy in adjuvant or neoadjuvant setting, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Participants With Types of Endocrine Therapy in Adjuvant or Neoadjuvant Setting | Number of participants with types of endocrine therapy in adjuvant or neoadjuvant setting, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants Who Received Endocrine Therapy in Advanced, Disease Modifying or Metastatic Setting | Percentage of participants who received endocrine therapy in advanced, disease modifying or metastatic setting, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants With Type of Endocrine Therapy in Advanced, Disease Modifying or Metastatic Setting | Percentage of participants with type of endocrine therapy in advanced, disease modifying or metastatic setting, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Lines of Prior Endocrine Therapy for Metastatic Disease | Number of lines of prior endocrine therapy for metastatic disease during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Participants Who Received Radiotherapy in Advanced, Disease Modifying or Metastatic Setting | Number of participants who received radiotherapy in advanced, disease modifying or metastatic setting, during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Percentage of Participants Who Received Concomitant Medications | Percentage of participants who received concomitant medications, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Participants With Concomitant Medications Prescribed Along With Goserelin | Number of participants with concomitant medications prescribed along with goserelin, during anytime between initial BC disease diagnosis and index date were reported in this outcome measure. Goserelin is the generic drug with a brand name Zoladex. | At baseline | 
| Number of Participants According to Number of Prior Treatments in Metastatic Setting | Number of participants according to number of prior treatments in metastatic setting, during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Participants According to Number of Prior Chemotherapy and Hormone Therapy in Metastatic Setting | Number of participants according to number of prior chemotherapy and hormone therapy in metastatic setting, during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Participants According to Number of Prior Chemotherapies in Metastatic Setting | Number of participants according to number of prior chemotherapies in metastatic setting, during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 
| Number of Participants According to Number of Prior Hormone Therapies in Metastatic Setting | Number of participants according to number of prior hormone therapies in metastatic setting, during anytime between MBC disease diagnosis and index date were reported in this outcome measure. | At baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants With Their Starting Dose of Palbociclib | Percentage of participants with their starting dose of palbociclib were reported. | Data collected at index date (for a maximum period of 3 years) | 
| Percentage of Participants Who Received Endocrine Therapy Along With Palbociclib | Percentage of participants who received endocrine therapy along with palbociclib were reported in this outcome measure. Endocrine therapy includes anastrozole, exemestane, fulvestrant and letrozole. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants With Dose Reductions and Treatment Discontinuation | Percentage of participants with dose reductions and treatment discontinuation were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Number of Participants With Reasons for Palbociclib Discontinuation | Number of participants with reasons for palbociclib discontinuation were reported in this outcome measure. Disease progression (PD) was defined as greater than or equal to (>=)20 percent (%) increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 millimeter (mm) or appearance of 1 or more new lesions. Adverse drug reactions (ADR) were defined as unintended, harmful events attributed to the use of drug. As per World Health Organisation (WHO) criteria for hematologic and nonhematologic toxicity grade 3 was defined as the severe/worst grade. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants With Temporary Discontinuation | Percentage of participants with temporary discontinuation of palbociclib were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants According to Time to Dose Reduction in First Line Therapy | Percentage of participants according to time to dose reduction after palbociclib initiation in 1st line therapy were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Time to Palbociclib Discontinuation | Time to palbociclib discontinuation were observed in participants who permanently discontinued palbociclib and were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Number of Participants With First 3 Lines of Treatment After Progression | Number of participants according to lines of treatment after progression were reported in this outcome measure. | Data collected from date of progression until lost to follow up or end of follow up period, whichever occurred first (for a maximum period of 3 years) | 
| Doses Prescribed for First 3 Lines of Treatment After Progression | Doses of drugs prescribed for first 3 lines of treatment after progression were reported in this outcome measure. | Data collected from date of progression until lost to follow up or end of follow up period, whichever occurred first (for a maximum period of 3 years) | 
| Duration of First 3 Lines of Treatment After Progression | Time duration of first 3 lines of treatment after progression up to lost to follow up or end of follow up period, whichever occurred first were reported in this outcome measure. | Data collected from date of progression until lost to follow up or end of follow up period, whichever occurred first (for a maximum period of 3 years) | 
| Number of Completed Cycles of Palbociclib | Number of 28-day cycles completed for palbociclib treatment were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants Who Received Letrozole and Fulvestrant With Palbociclib | Percentage of participants who received letrozole and fulvestrant along with palbociclib were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants With Progression Free Survival Following Palbociclib Initiation | Progression free survival (PFS) was defined as the time from the index date to the date of first documented disease progression (PD) or death. PD was defined as >=20% increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 mm or appearance of 1 or more new lesions. Percentage of participants with progression free survival after index date were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants Alive Following Palbociclib Initiation | Percentage of participants who were alive after palbociclib initiation were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants With Partial Response (PR) and Complete Response (CR) Following Palbociclib Initiation | CR was defined as disappearance of target, non-target lesions and normalization of tumor markers. Pathological lymph nodes had short axis measures less than (<)10 mm; PR was defined as >=30% decrease in sum of measures (longest diameter for tumor lesions, short axis measure for nodes) of target lesions, taking reference baseline sum of diameters. Non-target lesions must be non-PD; PD: >=20% increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 mm or appearance of 1 or more new lesions. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants With Stable Disease (SD) Following Palbociclib Initiation | SD was defined as neither shrinkage for CR or PR nor increase for PD taking as reference smallest sum of longest diameters since treatment start. Alive participants with no events were censored at date of last response assessment. CR: disappearance of target, non-target lesions and normalization of tumor markers. Pathological lymph nodes had short axis measures <10 mm; PR: >=30% decrease in sum of measures (longest diameter for tumor lesions, short axis measure for nodes) of target lesions, taking reference baseline sum of diameters. Non-target lesions must be non-PD; PD: >=20% increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 mm or appearance of 1 or more new lesions. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Progression Free Survival (PFS) | PFS was defined as the time from the index date to the date of first documented PD or death. PD was defined as at least a 20% increase in sum of diameters of target lesions, taking as reference the smallest sum on study. In addition to relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. The appearance of one or more new lesions was also considered progression. | From index date to PD or death whichever occurred first (for a maximum period of 3 years) | 
| Overall Survival (OS) | OS was defined as the time between the index date and the date of death from any cause. Participants who were still alive at the last date of data collection were censored. | From index date until date of death or date of censoring (for a maximum period of 3 years) | 
| Time to Achieving Best Overall Response (BOR) | Time to achieving BOR: time from index date until achievement of BOR: CR or PR, if CR was not achieved during follow-up. CR: disappearance of target, non-target lesions and normalization of tumor markers. Pathological lymph nodes had short axis measures <10 mm; PR: >=30% decrease in sum of measures (longest diameter for tumor lesions, short axis measure for nodes) of target lesions, taking reference baseline sum of diameters. Non-target lesions must be non-PD; PD: >=20% increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 mm. Appearance of 1 or more new lesions; Alive participants with no events were censored at date of last response assessment. | From index date till date of BOR or date of censoring (for a maximum period of 3 years) | 
| Duration of Follow-up Period | Duration of follow-up period defined as the duration from index date until lost to follow up or end of follow up period, whichever occurred first, were reported in this outcome measure. | Data collected from index date until lost to follow up or end of follow up, whichever occurred first (for a maximum period of 3 years) | 
| Percentage of Participants With Best Response (BR), Progressive Disease (PD) and Stable Disease (SD) to Palbociclib | Percentage of participants with BR, PD and SD to palbociclib were reported in this outcome measure. BR was recorded for CR or PR. CR: disappearance of target, non-target lesions and normalization of tumor markers. Pathological lymph nodes had short axis measures <10 mm; PR: >=30% decrease in sum of measures (longest diameter for tumor lesions, short axis measure for nodes) of target lesions, taking reference baseline sum of diameters. Non-target lesions must be non-PD; PD: >=20% increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 mm or appearance of 1 or more new lesions. SD: neither shrinkage for CR/PR nor increase for PD taking as reference smallest sum of longest diameters since treatment start. Alive participants with no events were censored at date of last response assessment. | From index date till BR (CR or PR, whichever occurred first), SD, PD or date of censoring (for a maximum period of 3 years) | 
| Time to Best Response (BR) | Time to BR: time from index date until achievement of BR:CR or PR, if CR not achieved during follow-up. CR: disappearance of target, non-target lesions and normalization of tumor markers. Pathological lymph nodes had short axis measures <10 mm; PR: >=30% decrease in sum of measures (longest diameter for tumor lesions, short axis measure for nodes) of target lesions, taking reference baseline sum of diameters. Non-target lesions must be non-PD; PD: >=20% increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 mm or appearance of 1 or more new lesions. Alive participants with no events were censored at date of last response assessment. Data is also presented by de novo status and relapse status. | From index date till BR or date of censoring (for a maximum period of 3 years) | 
| Time to First Response | Time to first response: time from index date until achievement of first response of CR or PR, if CR not achieved during follow-up. CR: disappearance of target, non-target lesions and normalization of tumor markers. Pathological lymph nodes had short axis measures <10 mm; PR: >=30% decrease in sum of measures (longest diameter for tumor lesions, short axis measure for nodes) of target lesions, taking reference baseline sum of diameters. Non-target lesions must be non-PD; PD: >=20% increase in sum of diameters of target lesions, taking as reference smallest sum on study, sum must demonstrate absolute increase of at least 5 mm or appearance of 1 or more new lesions. Alive participants with no events were censored at date of last response assessment. Data is also presented by de novo status and relapse status. | From index date till first documented CR or PR or date of censoring (for a maximum period of 3 years) | 
| Percentage of Participants With Neutropenia Post-Palbociclib Initiation | Neutropenia is an abnormally low level of neutrophils with count <1500 neutrophils per microliter (mcL) in blood and was classified as per Common Toxicity Criteria (CTC) version 2.0 criteria: grade 1 (mild) with an absolute neutrophil count (ANC) of >=1500 to <2000 cells per mcL, grade 2 (moderate) with an ANC of >=1000 to <1500 cells per mcL, grade 3 (severe) with an ANC of >=500 to <1000 cells per mcL or grade 4 (severe) with an ANC lower than 500 cells per mcL. Percentage of participants with all grades, grade 3 and grade 4 were reported in this outcome measure. All grades category included grades 1 to grade 4. | Data collected from index date up to 6 months post-palbociclib initiation (for a maximum period of 3 years) | 
| Percentage of Participants With Neutropenia Post-Palbociclib Initiation as Recorded and Inferred From Clinical Notes | Neutropenia is an abnormally low level of neutrophils with count <1500 neutrophils per mcL in blood and was classified as per CTC version 2.0 criteria: grade 1 (mild) with an ANC of >=1500 to <2000 cells per mcL, grade 2 (moderate) with an ANC of >=1000 to <1500 cells per mcL, grade 3 (severe) with an ANC of >=500 to <1000 cells per mcL or grade 4 (severe) with an ANC lower than 500 cells per mcL. | Data collected from index date up to 6 months post-palbociclib initiation (for a maximum period of 3 years) | 
| Percentage of Participants With Neutropenia Post-Palbociclib Initiation as Recorded and Inferred From ANC Measurements | Neutropenia is an abnormally low level of neutrophils with count <1500 neutrophils per mcL in blood and was classified as per CTC version 2.0 criteria: grade 1 (mild) with an ANC of >=1500 to <2000 cells per mcL, grade 2 (moderate) with an ANC of >=1000 to <1500 cells per mcL, grade 3 (severe) with an ANC of >=500 to <1000 cells per mcL or grade 4 (severe) with an ANC lower than 500 cells per mcL. | Data collected from index date up to 6 months post-palbociclib initiation (for a maximum period of 3 years) | 
| Percentage of Participants According to the Severe Grade of Neutropenia | Neutropenia is an abnormally low level of neutrophils with count <1500 neutrophils per mcL in blood and was classified as per CTC version 2.0 criteria: grade 1 (mild) with an ANC of >=1500 to <2000 cells per mcL, grade 2 (moderate) with an ANC of >=1000 to <1500 cells per mcL, grade 3 (severe) with an ANC of >=500 to <1000 cells per mcL or grade 4 (severe) with an ANC lower than 500 cells per mcL. Percentage of participants with grade 3 and 4 were reported in this outcome measure. | Data collected from index date up to 3 months post-palbociclib initiation (for a maximum period of 3 years) | 
| Percentage of Participants With Febrile Neutropenia Post-Palbociclib Initiation | Febrile neutropenia (FN) was defined as an ANC of < 1.0 x 10^9 cells/L predicted to fall below 0.5 x 10^9 cells/L within 48 hours with fever or clinical signs of sepsis; fever and ANC were measured the same day or within ± 1 calendar day. | Data collected from index date up to 3 months post-palbociclib initiation (for a maximum period of 3 years) | 
| Percentage of Participants With Gastro-Intestinal Toxicities Post-Palbociclib Initiation | Percentage of participants with gastro-intestinal toxicities as diarrhea, nausea and vomiting after index date were reported in this outcome measure. As per CTC version 2.0 criteria, for diarrhea: grade 1 (mild)- less than 4 stools per day, grade 2 (moderate)- 4 to 6 stools per day, grade 3 (severe)- >=7 stools per day and grade 4 (life-threatening)- physiologic consequences requiring intensive care; Vomiting: grade 1 (mild)- 1 episode per day , grade 2 (moderate)- 2 to 5 episodes per day, grade 3 (severe)- >=6 episodes per day and grade 4 (life-threatening)- physiologic consequences requiring intensive care; Nausea: grade 1 (mild)- able to eat, grade 2 (moderate)- oral intake significantly reduced, grade 3 (severe)- no significant intake and requiring intravenous fluids. | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Percentage of Participants With Adverse Events During Follow-up | Percentage of participants with at least one of the adverse events (neutropenia, diarrhea, nausea, and vomiting) after index date were reported in this outcome measure. | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Absolute Values for Hematology Parameter in First 6 Months Following Palbociclib Initiation: Hemoglobin | Absolute values for hematology parameter- hemoglobin, were reported in this outcome measure. | From index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Absolute Values for Hematology Parameters in First 6 Months Following Palbociclib Initiation: White Blood Cell, Absolute Neutrophil Counts and Platelet Counts | Absolute values for hematology parameters- white blood cell (WBC) counts, absolute neutrophil counts (ANC) and platelet counts (PLT), were reported in this outcome measure. | Data collected from index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Absolute Values for Liver Function Parameters in First 6 Months Following Palbociclib Initiation: Aspartate Aminotransferase, Alanine Aminotransferase and Alkaline Phosphatase | Absolute values for liver function parameters- Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT) and Alkaline Phosphatase (ALP), were reported in this outcome measure. | Data collected from index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Absolute Values for Liver Function Parameter in First 6 Months Following Palbociclib Initiation: Albumin | Absolute values for liver function parameter- albumin, were reported in this outcome measure. | Data collected from index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Absolute Values for Liver Function Parameter in First 6 Months Following Palbociclib Initiation: Bilirubin | Absolute values for liver function parameter- bilirubin, were reported in this outcome measure. | Data collected from index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Absolute Values for Bone Profile Parameters in First 6 Months Following Palbociclib Initiation: Calcium and Phosphate | Absolute values for bone profile parameters- calcium and phosphate were reported in this outcome measure. | Data collected from index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Absolute Values for Clinical Chemistry Parameters in First 6 Months Following Palbociclib Initiation: Potassium, Sodium and Urea | Absolute values for clinical chemistry parameters- potassium, sodium and urea were reported in this outcome measure. | Data collected from index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Absolute Values for Clinical Chemistry Parameter in First 6 Months Following Palbociclib Initiation: Creatinine | Absolute values for clinical chemistry parameter- creatinine, were reported in this outcome measure. | Data collected from index date up to 6 months after palbociclib initiation (for a maximum period of 3 years) | 
| Percentage of Participants With Inpatient Admissions and Outpatient Visits | Percentage of participants with inpatient admissions and outpatient visits were reported in this outcome measure. | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Number of Inpatient Admissions Per Participant |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Number of Outpatient Visits Per Participant |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Percentage of Participants With Type of Hospital Admission |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Percentage of Participants With Reasons for Hospital Admission |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Duration of Inpatient Hospital Stay | Duration of hospital stay was the time from the date of hospital entry to date of hospital discharge. | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Reasons of Outpatient Visit |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Type of Health Care Professional Consultations During Outpatient Visit |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Percentage of Participants Contacted Cancer National Service (CNS) and Acute Oncology Service (AOS) During First Year After Palbociclib Initiation | Percentage of participants who contacted CNS by phone calls and AOS either by phone calls or visits were reported in this outcome measure. | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Percentage of Participants According to Number of CNS Interactions |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Number of AOS Interactions Per Participant |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Type of CNS and AOS Interactions |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) | 
| Reasons for CNS and AOS Interaction |  | Data collected from index date up to 1-year of follow up period (for a maximum period of 3 years) |