Pembrolizumab and Binimetinib in Treating Patients With Locally Advanced or Metastatic Triple Negative Breast Cancer

PRIMARY OBJECTIVES:

I. To determine the maximum tolerated dose (MTD) of binimetinib in combination with
pembrolizumab. (Phase I) II. To evaluate the objective response rate (ORR) of binimetinib in
combination with pembrolizumab in patients with unresectable locally advanced or metastatic
triple negative breast cancer by Response Evaluation Criteria in Solid Tumors (RECIST).
(Phase II)

SECONDARY OBJECTIVES:

I. To evaluate the safety and tolerability of binimetinib in combination with pembrolizumab.

II. To evaluate the ORR by immune-related RECIST criteria (irRECIST). III. To evaluate the
progression free survival (PFS), duration of response (DoR), and disease control rate (DCR)
by RECIST and irRECIST.

IV. To assess overall survival (OS).

TERTIARY OBJECTIVES:

I. To assess the correlation between ORR, progression free survival (PFS), or overall
survival (OS) and baseline and/or change in tumor infiltrating lymphocytes (TILs).

II. To assess the correlation between ORR, PFS, or OS and baseline and/or change in immune
related gene signature and PDJ amplification.

III. To assess the change in immunoregulatory cells (IRC). IV. To assess the change in the
cytokine profile. V. To assess the change in circulating tumor cells (CTC).

OUTLINE: This is phase I, dose-escalation study of binimetinib followed by a phase II study.

Patients receive binimetinib orally (PO) twice daily (BID) on days 1-14 of course 1 and on
days 1-21 of course 2 and subsequent courses. Patients also receive pembrolizumab
intravenously (IV) over 30 minutes on day 1. Course 1 equals 14 days. Courses 2 and beyond
repeat every 21 days in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 30 days and then every 3 or
6 months for up to 3 years.

Inclusion Criteria:

- Histological confirmation of adenocarcinoma of the breast

- Estrogen receptor (ER) and progesterone receptor (PR) negative; defined as ER =< 10%
and PR =< 10% staining by immunohistochemistry (IHC)

- HER2 negative in the primary or metastatic tumor tissue defined as:

- Immunohistochemistry (IHC) grade 0 as defined by no staining observed or membrane
staining that is incomplete and is faint/barely perceptible and within =< 10% of
the invasive tumor cell; OR

- IHC 1+ as defined by incomplete membrane staining that is faint/barely
perceptible and within > 10% of the invasive tumor cell; OR

- IHC grade 2+ staining intensity by means of IHC analysis with no gene
amplification below; OR

- No gene amplification on in situ hybridization (ISH) based on:

- Single-probe average HER2 copy number < 4.0 signals/cell OR

- Dual-probe HER2/CEP17 ratio < 2.0 with an average HER2 copy number < 4.0
signals/cell

- =< 3 prior lines of treatment in the metastatic setting for the current breast cancer

- Measurable disease

- Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 or 1

- Hemoglobin >= 9.0 g/dL (must be >= 7 days after most recent transfusion)

- Absolute neutrophil count (ANC) >= 1500/mm^3 or >= 1.5 x 10^9/L

- Platelet count >= 100,000/mm^3 or >= 100 x 10^9/L (must be >= 7 days after most recent
transfusion)

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

- Aspartate transaminase (AST) and/or alanine transaminase (ALT) =< 2.5 x ULN or =< 5 x
ULN for patients with liver metastases

- Creatinine =< 1.5 x ULN OR

- Calculated creatinine clearance must be >= 50 ml/min using the Cockcroft-Gault formula

- International normalized ratio (INR) or prothrombin time (PT) and activated partial
thromboplastin time (aPTT) =< 1.5 x ULN unless patient is receiving anticoagulant
therapy as long as PT or PTT is within therapeutic range of intended use of
anticoagulants

- Adequate cardiac function:

- Left ventricular ejection fraction (LVEF) >= 50% as determined by multigated
acquisition (MUGA) scan or echocardiogram (echo)

- Corrected QT (QTc) interval =< 480 ms

- Negative serum pregnancy test done =< 7 days prior to registration, for women of
childbearing potential only

- Able to swallow oral medication

- Both female and male patients of reproductive potential must agree to avoid pregnancy
or impregnating a partner (respectively) while receiving drug and for 120 days after
last dose of study drug

- Provide written informed consent

- Willing to return to enrolling institution for follow-up (during the active monitoring
phase of the study)

- Willing to provide mandatory tissue and blood for correlative research purposes

Exclusion Criteria:

- Any of the following:

- Pregnant women

- Nursing women

- Men or women of childbearing potential who are unwilling to employ adequate
contraception

- Receiving any other investigational agent which would be considered as a treatment for
the primary neoplasm OR participated in a study of an investigational agent, received
study therapy or used an investigational device =< 4 weeks prior to registration

- Received prior therapy with anti-PD-1, anti-PD-L1 or anti-PD-L2 agent or MEK inhibitor

- Immunocompromised patients and patients with known immunodeficiency; or receiving
systemic steroid therapy or any other immunosuppressive therapy =< 7 days prior to
registration; NOTE: inhaled steroids and low-dose corticosteroids are allowed

- History of active tuberculosis (TB), human immunodeficiency virus (HIV), active
hepatitis B (e.g., hepatitis B surface antigen [HBsAg] reactive) and/or active
hepatitis C infection (e.g. hepatitis C virus [HCV] ribonucleic acid [RNA] qualitative
is detected)

- Received a live vaccine =< 30 days prior to registration; NOTE: seasonal influenza
vaccines for injection are generally inactivated flu vaccines and are allowed; however
intranasal influenza vaccines (e.g., FluMist) are live attenuated vaccines, and are
not allowed

- Hypersensitivity to pembrolizumab, binimetinib, or any excipients of either drug

- Prior anti-cancer therapy with a monoclonal antibody (mAb) =< 4 weeks prior to
registration OR failure to recover (to =< grade 1) from adverse events (AE)
attributable to agents received > 4 weeks prior to registration

- Prior therapy including chemotherapy, targeted small molecule therapy or radiation
therapy =< 2 weeks prior to registration OR failure to recover (to =< grade 1 or to
baseline) from adverse events (AE) attributable to agents received > 4 weeks prior to
registration; NOTE: exception for neuropathy =< grade 2, which is allowed

- Any active central nervous system (CNS) lesion (i.e., those with radiographically
unstable, symptomatic lesions) and/or leptomeningeal metastases; NOTE: patients
treated with stereotactic radiotherapy or surgery are eligible if no evidence of CNS
disease progression >= 4 weeks and patients must be off corticosteroid therapy for >=
3 weeks; NOTE: carcinomatous meningitis is excluded regardless of clinical stability

- Active autoimmune disease requiring systemic treatment in the past 2 years (i.e. use
of disease modifying agents, corticosteroids or immunosuppressive drugs); NOTE:
replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid
replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a
form of systemic treatment

- Known history of, or any evidence of active, non-infectious pneumonitis

- Active infection requiring systemic therapy

- Known history of acute or chronic pancreatitis

- History of or current evidence of retinal vein occlusion (RVO) or predisposing factors
to RVO (e.g. uncontrolled glaucoma or ocular hypertension, history of hyperviscosity
or hypercoagulability syndromes)

- History of retinal degenerative disease

- History of Gilbert's syndrome

- Other active malignancy =< 3 years prior to registration; EXCEPTIONS: adequately
treated non-melanotic skin cancer (adequate wound healing is required prior to study
entry) or carcinoma-in-situ of the cervix; NOTE: if there is a history of prior solid
tumor malignancy, it must have been treated curatively with no evidence of recurrence
=< 3 years prior to registration

- Impaired cardiovascular function or clinically specific cardiovascular disease
including any of the following:

- History of acute coronary syndromes (including myocardial infarction unstable
angina, coronary artery bypass grafting, coronary angioplasty, or stenting) =< 6
months; OR

- Symptomatic chronic heart failure history or current evidence of clinically
significant cardiac arrhythmia and/or conduction abnormality < 6 months prior to
screening; except atrial fibrillation and paroxysmal supraventricular tachycardia

- Uncontrolled arterial hypertension defined as persistent elevation of systolic blood
pressure >= 150 mmHg or diastolic blood pressure >= 100 mmHg despite medical treatment

- History of neuromuscular disorders that are associated with elevated creatine kinase
(CK) (e.g., inflammatory myopathies, muscular dystrophy, amyotrophic lateral
sclerosis, spinal muscular atrophy)

- Planning to embark on a new strenuous exercise regimen after first dose of study
treatment; NOTE: muscular activities, such as strenuous exercise, that can result in
significant increases in plasma CK levels should be avoided while on binimetinib
treatment

- Impairment of gastrointestinal function or gastrointestinal disease (e.g., ulcerative
disease, uncontrolled nausea, vomiting, diarrhea, malabsorption syndrome, small bowel
resection); NOTE: gastric bypass is allowed

- 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.

- Major surgery =< 3 weeks prior to registration or failure to adequately recover from
surgery

- Medical, psychiatric, cognitive or other conditions that may compromise the patient's
ability to understand the patient information, give informed consent, comply with the
study protocol or complete the study