Endocrine Therapy With or Without Abemaciclib (LY2835219) Following Surgery in Participants With Breast Cancer
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Intervention: Abemaciclib; Standard Adjuvant Endocrine Therapy
Intervention description: Administered orally.; Administered according to label instructions.
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Enrollment: 5637.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: early stage breast cancer; cyclin-dependent kinase (CDK)

Summary:

      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.
    

Eligibility criteria:

        Inclusion Criteria:

          -  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 surgery of the primary breast tumor.

          -  The participant must have tumor tissue from breast (preferred) or lymph node for
             exploratory biomarker analysis available prior to randomization.

          -  Pathologic lymph node involvement and at least one of the following indicating a
             higher risk of recurrence:

               -  4 or more positive axillary lymph nodes

               -  Tumor size of at least 5 centimeters

               -  Grade 3 defined as at least 8 points on the Bloom Richardson grading system

               -  Ki-67 index by central analysis of ≥20% on untreated breast tissue

          -  The participant must be randomized within 16 months from the time of definitive breast
             cancer surgery.

          -  The participant may receive up to 12 weeks of endocrine therapy until randomization
             following the last non-endocrine therapy (surgery, chemotherapy, or radiation)
             whichever is last.

          -  Participants must have recovered (grade ≤1) 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 a Eastern Cooperative Oncology Group (ECOG) performance status ≤1.

          -  The participant has adequate organ function.

          -  The participant is able to swallow oral medications.

        Exclusion Criteria:

          -  Metastatic disease (including contralateral axillary lymph nodes) or node-negative
             disease.

          -  Participants with inflammatory breast cancer.

          -  Participants with a history of previous breast cancer, with the exception of
             ipsilateral ductal carcinoma in situ (DCIS) treated by locoregional therapy alone ≥5
             years ago. Participants with a history of contralateral DCIS treated by local regional
             therapy at any time may be eligible. 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 from the date of
             randomization 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 aromatase inhibitors) or raloxifene.

          -  The participant has serious preexisting 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).

          -  The participant has active systemic infections 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.