A Real-World Study of Early Breast Cancer Patients Eligible for Treatment With CDK4/6 Inhibitors

Novartis Pharmaceuticals750 enrolled

Overview

The aim of this study was to describe treatment patterns, patient characteristics and clinical outcomes among hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) early breast cancer (eBC) patients who became eligible for treatment with cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) in the real-world setting after the FDA approval of ribociclib treatment for eBC. The study used data abstracted from structured and unstructured patient electronic health records from sites available in the Integra Connect PrecisionQ database (secondary data use).

Study Type

OBSERVATIONAL

Enrollment

750

Conditions

Breast Cancer

Eligibility

Sex: ALLMin age: 18 YearsMax age: 100 Years

Medical Language ↔ Plain English

Inclusion criteria: * Diagnosed with HR+/HER2- breast cancer. * No evidence of distant metastatic spread. * Underwent primary breast cancer surgery (mastectomy/lumpectomy) during the study period. * Initiated adjuvant ET within 12 months of surgery date and after September 17, 2024, to the period up to 3 months prior to the data cutoff date. * Had at least one visit during the baseline period and at least one visit one day after the index date. * Patients included must have met one of the following conditions at the time of diagnosis or surgery: 1. Nodal stage (N) N2 or N3 disease. 2. N1 any anatomic tumor size (T), including micrometastatic patients except T0 N1mi and T1 N1mi; For T0 N1mi and T1 N1mi patients with Grade 3 disease alone will be selected. 3. Node-negative with the following high-risk criteria: 1. Tumor size is T3, T4 2. Tumor size is T2 and Grade 3 3. Tumor size is T2 with Grade 2 and either Ki-67 score ≥ 20% or genomic high risk based on Oncotype Dx/Mammaprint/Endopredict/Prosigna Exclusion criteria: * Use of any prior CDK4/6i before the index date. * Missing T or N values for both clinical and surgical stage. * Diagnosis of cancer other than breast cancer. * Evidence of participation in a clinical trial at any time during the study observation period.

Outcomes

Primary Outcomes

Percentage of Eligible Population that Received Genetic Testing

Testing includes germline mutation testing, Oncotype DX testing, Ki-67 scoring, and other breast cancer specific genetic tests (breast cancer index, Mammaprint, Endopredict, Prosigna).

Time frame: Baseline, up to approximately 1 year, 7 months

Number and Percentage of Patients by Treatment Regimen

Number and percentage of patients by treatment regimen in the neo-adjuvant and adjuvant setting, stratified by patient and provider characteristics, and CDK4/6i eligibility.

Time frame: Baseline, up to approximately 1 year, 7 months

Number and Percentage of Patients With Treatment Switches

Number and percentage of patients with treatment switches within the CDK4/6i and aromatase inhibitor (AI) drug classes, classified as switch due to toxicity vs. other reason.

Time frame: Baseline, up to approximately 1 year, 7 months

Time From Surgery to Start of Adjuvant ET

Time frame: Up to 1 year

Time From Surgery to Start of CDK4/6i Treatment

Time frame: Up to 1 year

Time From ET to Start of CDK4/6i Treatment

Time frame: Up to approximately 1 year, 7 months

Time From Adjuvant Chemotherapy to Start of CDK4/6i Treatment

Time from initial adjuvant Chemotherapy to the start of CDK4/6i treatment, stratified by presence of adverse events prior to CDK4/6i initiation.

Time frame: Up to approximately 1 year, 4 months

Secondary Outcomes

Baseline Demographics

Time frame: Baseline

Height

Time frame: Baseline

Weight

Time frame: Baseline

Body Mass Index (BMI)

Time frame: Baseline

Number and Percentage of Patients by Patient Characteristics

Patient characteristics include: * Menopausal status * Geographic location * Payer type * Index year * Vital status

Time frame: Baseline

Age at Initial Diagnosis of BC

Time frame: Baseline

Duration Between Diagnosis of BC and Initiation of Adjuvant ET

Time frame: Baseline

Number and Percentage of Patients by Clinical Characteristics

Clinical characteristics include: * Eastern Cooperative Oncology Group (ECOG) performance status grade * Tumor, Node, Metastasis (T.N.M) classification at BC diagnosis and after surgery * Anatomical staging at BC diagnosis * Tumor grade at BC diagnosis * HR+ and HER2- status * QT prolongation * Molecular subtype * Mutation status * Genomic scoring tests (where available) * Comorbidities * Adverse events

Time frame: Baseline

Red Blood Cell Count

Time frame: Basline

Hemoglobin Level

Time frame: Baseline

Hematocrit Level

Time frame: Baseline

White Blood Cell Count

Time frame: Baseline

Platelet Count

Time frame: Baseline

Absolute Neutrophil Count (ANC)

Time frame: Baseline

Serum Creatinine Level

Time frame: Baseline

Liver Enzyme Levels

* Aspartate aminotransferase (AST) * Alanine aminotransferase (ALT) * Alkaline phosphatase (ALP)

Time frame: Baseline

Bilirubin Level

Time frame: Baseline

Number and Percentage of Patients by Medications Used and Procedures

Time frame: Baseline, up to approximately 1 year, 7 months

Time to Discontinuation or Death

Time to all-cause discontinuation or death (TTD-all cause), TTD-all cause but recurrence, and time to adverse event-related discontinuation or death (TTD from AE).

Time frame: Up to approximately 1 year, 7 months

Persistence of CDK4/6i Use

Persistence is defined as the number of days patients were taking a CDK4/6i during a pre-defined time-interval.

Time frame: Up to approximately 1 year, 7 months

Number and Percentage of Patients who Discontinued Adjuvant Treatment

Time frame: Up to approximately 1 year, 7 months

Number of Patients by Reason for CDK4/6i Treatment Discontinuation

Time frame: Up to approximately 1 year, 7 months

Duration of Treatment

Time frame: Up to approximately 1 year, 7 months

Percentage of Patients by Dose of Treatment

Time frame: Up to approximately 1 year, 7 months

Cumulative Dose

Cumulative dose is defined as the sum of individual doses during the initial adjuvant regimen.

Time frame: Up to approximately 1 year, 7 months

Dose Intensity

Dose intensity is defined as the cumulative dose / total time period of treatment.

Time frame: Up to approximately 1 year, 7 months

Relative Dose Intensity (RDI)

RDI is defined as the observed dose intensity / expected dose intensity x 100.

Time frame: Up to approximately 1 year, 7 months

Number and Percentage of Patients With Dose Reductions During Follow-up

Time frame: Up to approximately 1 year, 7 months

Time to First and Subsequent Dose Reductions of CDK4/6is

Time frame: Up to approximately 1 year, 7 months

Number and Percentage of Patients With Drug Interruptions

Time frame: Up to approximately 1 year, 7 months

A Real-World Study of Early Breast Cancer Patients Eligible for Treatment With CDK4/6 Inhibitors

Overview

Conditions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes