endocrine therapy with or without abemaciclib (ly2835219) following surgery in participants with breast cancer

Conditions: Breast Cancer

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.

Keywords: early stage breast cancer cyclin-dependent kinase (cdk)