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Abemaciclib and Letrozole in Treating Patients With Endometrial Cancer

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04049227
Recruitment Status : Recruiting
First Posted : August 8, 2019
Last Update Posted : August 14, 2019
National Cancer Institute (NCI)
Information provided by (Responsible Party):
Northwestern University

Brief Summary:
This early phase I trial studies how well abemaciclib and letrozole work in treating patients with endometrial cancer and determines whether there are changes in patients' cancer cell biomarkers (a genetic feature or specific protein) for cell growth before and after treatment. Antihormone therapy with aromatase inhibitors, such as letrozole, may lessen the amount of estrogen made by the body. Abemaciclib blocks the activities of a class of proteins called cyclin-dependent kinase, which are involved in cell duplication. Giving letrozole and abemaciclib together may slow down cancer cell growth in patients with endometrial cancer.

Condition or disease Intervention/treatment Phase
Endometrial Endometrioid Adenocarcinoma Drug: Abemaciclib Drug: Letrozole Procedure: Therapeutic Conventional Surgery Early Phase 1

Detailed Description:


I. To determine whether there are changes in Ki-67 expression from the pretreatment specimen (e.g. biopsy or dilation and curettage [D&C]) to the post-treatment hysterectomy specimen following treatment with letrozole and abemaciclib.


I. To determine the proportion of tumors with complete cell cycle arrest (CCCA) response as measured by Ki-67 expression between the pre-treatment tumor and the posttreatment tumor.

II. To identify biological characteristics of tumors (e.g. mismatch repair [MMR] status, PTEN mutational status, etc.) correlating with decreased Ki-67 expression induced by the letrozole and abemaciclib combination.

III. To determine the frequency of adverse events associated with use of abemaciclib and letrozole.


I. To evaluate the correlation of the expression of Ki-67 with that of cyclin D1, p16, pRB, and PTEN as well as with MMR deficiency.


Patients receive letrozole orally (PO) once daily (QD) and abemaciclib PO twice daily (BID) on days 1-14. Patients then undergo standard of care hysterectomy on day 15.

After completion of study treatment, patients are followed up at 30 days and at 2 and 6 weeks after surgery.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 27 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Pilot, Multicenter, Single Arm, Open Label, Surgical Window of Opportunity Study of Abemaciclib and Letrozole for Endometrioid Adenocarcinoma of the Endometrium
Actual Study Start Date : August 12, 2019
Estimated Primary Completion Date : July 1, 2021
Estimated Study Completion Date : July 1, 2023

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Treatment (letrozole, abemaciclib)
Patients receive letrozole PO QD and abemaciclib PO BID on days 1-14. Patients then undergo standard of care hysterectomy on day 15.
Drug: Abemaciclib
Given PO
Other Names:
  • LY-2835219
  • LY2835219
  • Verzenio

Drug: Letrozole
Given PO
Other Names:
  • CGS 20267
  • Femara

Procedure: Therapeutic Conventional Surgery
Undergo standard of care hysterectomy

Primary Outcome Measures :
  1. Changes in Ki-67 expression [ Time Frame: Baseline up to 6 weeks ]

Secondary Outcome Measures :
  1. Proportion of tumors with complete cell cycle arrest (CCCA) response [ Time Frame: At day 15 ]

    Will be measured by Ki-67 between the pre-treatment tumor and the post-treatment tumor. CCCA response is defined as less than 3% of tumor cells staining positive for Ki-67 from specimens obtained at time of hysterectomy. Baseline biomarker levels will be compared between patients who do vs.

    do not achieve complete CCCA using a two-sample t-test.

  2. Biological characteristics of tumors: MMR status [ Time Frame: Up to 6 weeks ]
    Will be measured to correlate with decreased Ki-67 expression induced by the letrozole and abemaciclib combination.

  3. Biological characteristics of tumors: PTEN mutational status [ Time Frame: Up to 6 weeks ]
    Will be measured to correlate with decreased Ki-67 expression induced by the letrozole and abemaciclib combination.

  4. Biological characteristics of tumors: expression of cyclin D1 [ Time Frame: Up to 6 weeks ]
    Will be measured to correlate with decreased Ki-67 expression induced by the letrozole and abemaciclib combination.

  5. Biological characteristics of tumors: p16 [ Time Frame: Up to 6 weeks ]
    Will be measured to correlate with decreased Ki-67 expression induced by the letrozole and abemaciclib combination.

  6. Biological characteristics of tumors: pRB [ Time Frame: Up to 6 weeks ]
    Will be measured to correlate with decreased Ki-67 expression induced by the letrozole and abemaciclib combination.

  7. Incidence of adverse events associated with abemaciclib and letrozole [ Time Frame: Up to 6 weeks ]
    Categorized and graded according to Common Terminology Criteria for Adverse Events (CTCAE) version (v)5.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients must have a new histologically confirmed diagnosis of endometrioid adenocarcinoma of the endometrium who are candidates for hysterectomy.

    • Note: Patients with recurrent disease are not eligible.
  • Patients must be willing to provide archival tumor biopsy slides from the specimen (e.g. endometrial biopsy or dilation and curettage) which diagnosed them with endometrial cancer.

    • (Please note: Given the amount of tissue obtained from these specimens is often much more than a core needle biopsy, we do not anticipate difficulties with insufficient tissue.)
  • Patients should be treatment naive. They should not have received any endometrial cancer directed therapy including medroxyprogesterone acetate, aromatase inhibitors, other hormonal treatments or radiation therapy for treatment of endometrial cancer.

    • Note: Patients can have used oral contraceptives or hormonal replacement therapy provided these were discontinued 28 days prior to trial enrollment.
  • Eastern Cooperative Oncology Group (ECOG) performance status =< 2 within 28 days prior to registration for protocol therapy.
  • Patients must have adequate organ function for all of the following criteria within 28 days of registration.
  • Absolute neutrophil count (ANC) >= 1.5 x 10^9 /L (within 28 days of registration).
  • Platelets >= 100 x 10^9 /L (within 28 days of registration).
  • Hemoglobin >= 8 g/dL (within 28 days of registration).

    • Patients may receive erythrocyte transfusions to achieve this hemoglobin level at the discretion of the investigator. Initial treatment must not begin earlier than the day after the erythrocyte transfusion.
  • Total bilirubin =< 1.5 x upper limit of normal (ULN) (within 28 days of registration).

    • Patients with Gilbert?s syndrome with a total bilirubin =< 2.0 times ULN and direct bilirubin within normal limits are permitted.
  • Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) =< 3 x ULN (within 28 days of registration).
  • Serum creatinine =< 1.5 x ULN (within 28 days of registration).
  • Patients with a history of surgical sterilization are eligible for this study. OR
  • Patients must have post-menopausal status due to menopause (surgical or natural). Patients must meet at least one of the following criteria:

    • Bilateral oophorectomy
    • Age >= 55 years
    • Age =< 55 years and amenorrhea (absence of menstruation) for > 12 months OR
  • Patients who are not post-menopausal or previously sterilized.

    • i.e. a female of childbearing potential (patients who are not post-menopausal), must have a negative serum pregnancy test within 7 days of the first dose of study treatment (abemaciclib and/or letrozole). Patient must agree to use adequate birth control (condoms with spermicidal agent or abstinence) while on the study and for 3 weeks after completion of treatment.
  • Patients should be able to swallow oral medications.
  • Patients must have the ability to understand and the willingness to sign a written informed consent prior to registration on study.
  • Patients must be willing and able to have a window of >= 15 days prior to their scheduled hysterectomy surgery after registration.

Exclusion Criteria:

  • Patients who have had chemotherapy, hormonal therapy or radiotherapy directed at the treatment of endometrial cancer prior to entering the study or those who have not recovered from adverse events due to agents administered more than 4 weeks prior to registration are not eligible.
  • Patients may not be receiving any other investigational agents. A wash out period of 4 weeks before registration is required for eligibility.
  • Patients who have a history of allergic reactions attributed to compounds of similar chemical or biologic composition to abemaciclib or letrozole or any of its excipients are not eligible.
  • Patients receiving CYP3A inducers or strong CYP3A inhibitors will not be eligible for this study. A wash-out period of minimum 5 half-lives or 7 days, whichever is shorter, before registration is required for the patient to become eligible.
  • Patients who have a known personal history of any of the following conditions: syncope of cardiovascular etiology, ventricular arrhythmia of pathological origin (including, but not limited to, ventricular tachycardia and ventricular fibrillation), or sudden cardiac arrest are not eligible.
  • Patients who have known active bacterial infection (requiring intravenous [IV] antibiotics at time of initiating study treatment), fungal infection, or detectable viral infection (such as known human immunodeficiency virus [HIV] positivity or with known active hepatitis B or C (for example, hepatitis B surface antigen positive). Screening is not required for enrollment.

    • Note: patients with uncomplicated urinary tract infection or uncomplicated cystitis are eligible.
  • Patients who have an uncontrolled intercurrent illness including, but not limited to any of the following, are not eligible:

    • Hypertension that is not controlled on medication
    • Baseline grade 2 or higher diarrhea.
    • Ongoing or active infection requiring systemic treatment.
    • Symptomatic congestive heart failure.
    • Unstable angina pectoris.
    • Psychiatric illness that would limit compliance with study requirements.
    • Social situations that would limit compliance with study requirements.
    • Serious preexisting medical condition(s) that would preclude participation in this study (for example, interstitial lung disease, severe dyspnea at rest or requiring oxygen therapy, history of major surgical resection involving the stomach or small bowel, or preexisting Crohn?s disease or ulcerative colitis or a preexisting chronic condition resulting in baseline grade 2 or higher diarrhea).
    • Any other illness or condition that the treating investigator feels would interfere with study compliance or would compromise the patient?s safety or study endpoints.
  • Female patients who are pregnant or nursing are not eligible.
  • Patients who are unable to retain oral medication, and patients who have gastrointestinal disorders or abnormalities that would interfere with absorption of the study drugs are not eligible.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04049227

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Contact: Study Coordinator (312)695-1301

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United States, Illinois
Northwestern University Recruiting
Chicago, Illinois, United States, 60611
Contact: Emma Barber, MD, MS    312-472-4684      
Principal Investigator: Emma Barber, MD, MS         
University of Chicago Comprehensive Cancer Center Not yet recruiting
Chicago, Illinois, United States, 60637
Contact: John W. Moroney    773-702-6118   
Principal Investigator: John W. Moroney         
Sponsors and Collaborators
Northwestern University
National Cancer Institute (NCI)
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Principal Investigator: Emma Barber, MD, MS Northwestern University
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Responsible Party: Northwestern University Identifier: NCT04049227    
Other Study ID Numbers: NU 18G07
STU00209370 ( CTRP (Clinical Trial Reporting Program) )
NU 18G07 ( Other Identifier: Northwestern University )
P30CA060553 ( U.S. NIH Grant/Contract )
NCI-2019-04599 ( Registry Identifier: CTRP (Clinical Trial Reporting Program) )
First Posted: August 8, 2019    Key Record Dates
Last Update Posted: August 14, 2019
Last Verified: August 2019

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Additional relevant MeSH terms:
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Carcinoma, Endometrioid
Neoplasms, Glandular and Epithelial
Neoplasms by Histologic Type
Endometrial Neoplasms
Uterine Neoplasms
Genital Neoplasms, Female
Urogenital Neoplasms
Neoplasms by Site
Ovarian Neoplasms
Ovarian Diseases
Adnexal Diseases
Gonadal Disorders
Endocrine System Diseases
Antineoplastic Agents
Aromatase Inhibitors
Steroid Synthesis Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Estrogen Antagonists
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs