Megestrol Acetate With or Without Pterostilbene in Treating Participants With Endometrial Cancer Undergoing Hysterectomy

PRIMARY OBJECTIVES:

I. Determine the effect of megestrol acetate (MA) plus pterostilbene (PTE) versus MA alone on
tumor proliferation (Ki-67) during the preoperative window in patients with endometrial
cancer (EC) who are scheduled for hysterectomy.

SECONDARY OBJECTIVES:

I. Determine the effect of MA plus PTE versus MA alone on histologic response during the
preoperative window in patients with EC who are scheduled for hysterectomy.

II. Explore biological characteristics of tumors to determine potential biomarkers which
could select for treatment eligibility in future studies.

All histologic data will be obtained from independent readings by 2 pathologists, whose
paired data values will be averaged prior to statistical analysis.

OUTLINE: Participants are randomized to 1 of 2 arms.

ARM I: Participants receive pterostilbene orally (PO) twice daily (BID) and megestrol acetate
PO BID for 3 weeks in the absence of disease progression or unaccepted toxicity.

ARM II: Participants receive megestrol acetate PO BID for 3 weeks in the absence of disease
progression or unaccepted toxicity.

After completion of study treatment, participants are followed up at 6 weeks.

Inclusion Criteria:

- Documented informed consent of the participant and/or legally authorized
representative

- Willing to undergo an intraoperative biopsy during surgery, following completion of
treatment with MA +/- PTE

- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2

- Histologically confirmed EC

- Candidate for a total hysterectomy with or without bilateral salpingo-oophorectomy

- About to initiate preoperative window period, with planned hysterectomy scheduled

- Platelets >= 100, 000/mm^3

- NOTE: Platelet transfusions are not permitted within 14 days of platelet
assessment unless cytopenia is secondary to disease involvement

- Total bilirubin =< 1.5 X upper limit of normal (ULN)

- Aspartate aminotransferase (AST) =< 1.5 x ULN

- Alanine aminotransferase (ALT) =< 1.5 x ULN

- Creatinine clearance of >= 60 mL/min per 24 hour urine test or the Cockcroft-Gault
formula

- Women of childbearing potential: negative urine or serum pregnancy test in
premenopausal women. Postmenopausal women do not need to undergo a pregnancy test. If
the urine test is positive or cannot be confirmed as negative, a serum pregnancy test
will be required

Exclusion Criteria:

- Pterostilbene supplements within 30 days prior to day 1 of protocol therapy

- Any of the following phytochemical-based supplements within 30 days prior to Day 1 of
protocol therapy: resveratrol, curcumin, genistein, and quercetin

- Chemotherapy for EC

- Progestins within 30 days prior to day 1 of protocol therapy, including
progestin-containing intrauterine devices (Mirena intrauterine device [IUD]), megace,
medroxyprogesterone, and progestin-only implants (e.g. Nexplanon)

- Allergic reaction/hypersensitivity to similar agents, excipients

- Unstable cardiac disease as defined by one of the following:

- Cardiac events such as myocardial infarction (MI) within the past 6 months

- NYHA (New York Heart Association) heart failure class III-IV

- Uncontrolled atrial fibrillation or hypertensive emergency/urgency (defined as
systolic blood pressure >= 180 mmHg and/or diastolic blood pressure >= 120 mmHg)

- History or evidence of stroke or thromboembolism

- Cushing's syndrome

- Acute infection requiring systemic (intravenous) treatment

- Known history of human immunodeficiency virus (HIV) infection

- Active hepatitis B or C infection

- Inability to swallow tablets/capsules

- Any other condition that would, in the Investigator's judgment, contraindicate the
patient's participation in the clinical study due to safety concerns or compliance
with clinical study procedures, e.g., infection/inflammation, intestinal obstruction,
unable to swallow medication, social/ psychological issues, etc

- Prospective participants who, in the opinion of the investigator, may not be able to
comply with all study procedures (including compliance issues related to
feasibility/logistics)