NSABP B-58: Endocrine Therapy With or Without Abemaciclib

A Randomized, Open-Label, Phase 3 Study of Abemaciclib Combined With Standard Adjuvant Endocrine Therapy Versus Standard Adjuvant Endocrine Therapy Alone in Patients With High Risk, Node-Positive, Early Stage, Hormone Receptor-Positive, Human Epidermal Receptor 2 Negative, Breast Cancer

Objective

Overview

The purpose of this study is to evaluate the safety and efficacy of the study drug abemaciclib in participants with high risk, node-positive, early stage, hormone receptor-positive (HR+), human epidermal receptor 2 negative (HER2-), breast cancer.

Key Inclusion Criteria

For a patient to be eligible for participation in this study, all of the following criteria must apply:

• Women (regardless of menopausal status) or men ≥18 years of age (or per local regulations).
• The participant has confirmed HR+, HER2-, early-stage resected invasive breast cancer without evidence of distant metastases.
• The participant must have undergone definitive surgical treatment for the current malignancy.
• The participant must have tumor tissue from the breast (preferred) or lymph node for exploratory biomarker analysis available prior to randomization.

• The participant must have axillary lymph node involvement by tumor and have one of the following indicating a higher risk of relapse:

  • Four or more axillary lymph nodes involved with cancer
  • Tumor size of at least 5 centimeters
  • Grade 3 histology
  • Ki67 index by central analysis of ≥20% on untreated breast tissue
• The participant must be randomized within 16 months from the time of surgery.
• If the participant is currently receiving or initiating standard adjuvant endocrine therapy at the time of study entry, she/he must not have received more than 12 weeks of adjuvant endocrine therapy following his/her last non-endocrine therapy (surgery, chemotherapy, or radiation).
• Participants must have recovered from the acute effects of chemotherapy and radiotherapy and from surgical side effects following definitive breast surgery.
• Women of reproductive potential must have a negative blood pregnancy test and agree to use highly effective contraceptive methods.
• The participant has an Eastern Cooperative Oncology Group (ECOG) performance status ≤1.
• The participant has adequate organ function.
• The participant is able to swallow oral medications.

Key Exclusion Criteria

A patient will not be eligible for participation in this study if any of the following criteria apply.

• Stage IV (M1), Stage IA, and lymph node-negative breast cancer.
• Participants with a history of previous breast cancer are excluded, with the exception of lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS) treated by locoregional therapy alone ≥5 years ago. Participants with a history of any other cancer (except non-melanoma skin cancer or carcinoma in situ of the cervix), unless in complete remission with no therapy for a minimum of 5 years are excluded.
• Females who are pregnant or lactating.
• The participant has previously received treatment with any CDK4 and CDK6 inhibitor.
• The participant is receiving concurrent exogenous reproductive hormone therapy (for example, birth control pills, hormone replacement therapy, or megestrol acetate).
• The participant has previously received endocrine therapy for breast cancer prevention (tamoxifen or raloxifene or aromatase inhibitors).
• The participant has a serious pre-existing medical condition(s) that, in the judgment of the investigator, would preclude participation in this study.
• The participant has a personal history of any of the following conditions: syncope of cardiovascular etiology, ventricular arrhythmia of pathological origin or sudden cardiac arrest. Any participant with a history of venous thromboembolism (VTE) (for example, deep vein thrombosis [DVT] of the leg or arm and/or pulmonary embolism) will be excluded.
• The participant has an active bacterial infection, fungal infection, or detectable viral infection or viral load.
• The participant has received an experimental treatment in a clinical trial within the last 30 days or 5 half-lives, whichever is longer.

Learn More

ClinicalTrials.Gov

IRB Protocol Number

NSABP B-58

Principal Investigator(s)

Amanda Hathaway, M.D.

Clinical Trial Categories

• Breast Cancer

Sponsor(s)

Eli Lilly and Company