Low Dose Ipilimumab With Pembrolizumab in Treating Patients With Melanoma That Has Spread to the Brain

PRIMARY OBJECTIVE:

I. To assess clinical benefit rate (CBR, defined as complete response [CR] + partial response
[PR] + stable disease [SD]) > 6 months in the brain in subjects with melanoma metastatic to
the brain per modified RECIST (Response evaluation criteria in solid tumors) 1.1 criteria and
RANO-BM (Response Assessment in Neuro-Oncology Brain Metastases), and who had experienced
prior progression on anti-PD1 (Programmed cell death protein).

SECONDARY OBJECTIVES:

I. Clinical benefit rate (CBR, defined as complete response [CR] + partial response [PR] +
stable disease [SD]) > 6 months in the brain in subjects with melanoma metastatic to the
brain per modified RECIST 1.1 and RANO-BM criteria, and who are treatment naive to anti- PD-1
agents.

II. To assess overall survival (OS) and progression free survival (PFS). III. To evaluate the
brain-specific safety and tolerability of the combination regimen in patients with or without
stereotactic radiotherapy (SRT) received prior to study entry, or on study.

IV. To evaluate cytokine levels and changes in the T-cell population in the cerebrospinal
fluid (CSF) and blood in patients treated with combination low dose ipilimumab and
pembrolizumab.

V. Changes in relative apparent diffusion coefficient as measured by MRI magnetic resonance
imaging as an early predictor of response.

VI. To assess changes in circulating cfDNA (cell-free deoxyribonucleic acid) as determinants
of response and/or markers of early progression.

VII. Evaluate molecular and immunological changes in extracranial lesions.

OUTLINE:

Patients receive ipilimumab intravenously (IV) over 90 minutes and pembrolizumab IV over 30
minutes on day 1. Treatment repeats every 3 weeks for up to 4 courses for ipilimumab and up
to 35 courses for pembrolizumab in the absence of disease progression or unacceptable
toxicity.

After completion of study treatment, patients are followed up at 30 days, every 6 weeks for
the first year, and then every 12 weeks thereafter.

Inclusion Criteria:

- Life Expectancy > 12 weeks.

- Subjects must have signed and dated an IRB/IEC (Institutional Review Board/Independent
Ethics Committee) approved written informed consent form in accordance with regulatory
and institutional guidelines. This must be obtained before the performance of any
protocol related procedures that are not part of normal subject care.

- Subjects must be willing and able to comply with scheduled visits, treatment schedule,
laboratory testing, and other requirements of the study.

- Histologically confirmed malignant melanoma with measurable metastases in the brain.

- At least one measurable intracranial target lesion for which all of the following
criteria are met: (1) Previously untreated or progressive after previous local therapy
(2) Immediate local therapy clinically not indicated or patient is not a suitable
candidate to receive immediate local therapy (3) Largest diameter of >= 0.5 cm, but =<
3 cm as determined by contrast-enhanced MRI.

- Representative formalin-fixed paraffin-embedded tumor specimens in paraffin blocks OR
at least 4 unstained slides with an associated pathology report for testing of tumor
PD-L1 expression (a) tumor tissue should be of good quality based on total and viable
tumor content. Fine-needle aspiration, brushing, cell pellet from pleural effusion,
bone metastases, and lavage samples are not acceptable. For core-needle biopsy
specimens, at least three cores should be submitted for evaluation (b) patients who do
not have tissue specimens may undergo a biopsy during the screening period. Acceptable
samples include core-needle biopsies for deep tumor tissue (minimum of three cores) or
excisional, incisional, punch, or forceps biopsies for cutaneous, subcutaneous, or
mucosal lesions (i) tumor tissue from bone metastases is not evaluable for PD-L1
expression and is therefore not acceptable (c) however, if repeat biopsy is not
feasible, and no archival tissue available patient still may be enrolled.

- Prior stereotactic radiotherapy (SRT) and prior excision of up to 5 melanoma brain
metastasis (MBM) is permitted if there has been complete recovery, with no neurologic
sequelae, and measurable lesions remain. Growth or change in a lesion previously
irradiated will not be considered measurable. Regrowth in cavity of previously excised
lesion will not be considered measurable. Note: Any prior SRT to brain lesions or
prior excision must have occurred >= 2 weeks before the start of dosing for this
study.

- Subjects must be free of neurologic signs and symptoms related to metastatic brain
lesions and must not have required or received systemic corticosteroid therapy in the
10 days prior to beginning protocol therapy.

- ECOG (Eastern Cooperative Oncology Group) performance status =< 1.

- Absolute neutrophil count >= 1500/uL.

- Platelets >= 100,000/uL.

- Hemoglobin >= 9.0 g/dL or >= 5.6 mmol/L.

- Creatinine =< 1.5 x upper limit of normal (ULN) OR measured or calculated creatinine
clearance >= 30L/min with creatinine levels > 1.5 x institutional ULN. GFR (glomerular
filtration rate) can also be used in place of creatinine or CrCl (creatinine
clearance).

- Total bilirubin =< 1.5 ULN OR direct bilirubin =< ULN for participants with total
bilirubin levels > 1.5 x ULN.

- AST (aspartate aminotransferase) and ALT (alanine aminotransferase) =< 2.5 x ULN (=< 5
x ULN for participants with liver metastasis).

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

- Women of child-bearing potential (WOCBP) must not be breastfeeding and must have a
negative pregnancy test within 3 days prior to initiation of dosing. She must agree to
use an acceptable method of birth control from the time of the negative pregnancy test
up to 120 days after the last dose of study drug. WOCBP must agree to adhere to the
contraceptive guidance in the protocol. Note: A female participant is eligible to
participate if she is not a woman of childbearing potential as defined by the
protocol.

- Fertile men must agree to use an acceptable method of birth control as described in
the protocol while on study drug and up to 120 days after the last dose of study drug
and also refrain from donating sperm during this period.

- All associated toxicity from previous or concurrent cancer therapy must be resolved
(to =< grade 1 or baseline) prior to study treatment administration.

- Steroids for physiological replacement are allowed.

Exclusion Criteria:

- History of known leptomeningeal involvement (lumbar puncture not required).

- Previous stereotactic or highly conformal radiotherapy within 2 weeks before the start
of dosing for this study. Note the stereotactic radiotherapy field must not have
included the brain index lesion(s).

- Subjects previously treated with SRT > 5 lesions in the brain

- Brain lesion size > 3 cm.

- (Cohort A) Prior PD-1 therapy. Note: Prior anti-PD1 therapy within the last 6 weeks of
enrollment on this protocol is allowed for Cohort B.

- Subjects with an active, known or suspected autoimmune disease. Subjects with type I
diabetes mellitus, hypothyroidism only requiring hormone replacement, skin disorders
(such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment, or
conditions not expected to recur in the absence of an external trigger are permitted
to enroll.

- Subjects with major medical, neurologic or psychiatric condition who are judged as
unable to fully comply with study therapy or assessments should not be enrolled.

- Active secondary malignancy unless the malignancy is not expected to interfere with
the evaluation of safety and is approved by the Medical Monitor. Examples of the
latter include basal or squamous cell carcinoma of the skin, in-situ carcinoma of the
cervix, and isolated elevation of prostate-specific antigen. Subjects with a
completely treated prior malignancy and no evidence of disease for >= 2 years are
eligible.

- Has a known history of or is positive for hepatitis B (hepatitis B surface antigen
[HBsAg] reactive) or hepatitis C (hepatitis C virus [HCV] ribonucleic acid (RNA)
[qualitative] is detected). Note: Without known history, testing needs to be performed
to determine eligibility. Hepatitis C antibody (Ab) testing is allowed for screening
purposes in countries where HCV RNA is not part of standard of care.

- Has a known history of human immunodeficiency virus (HIV) infection. No HIV testing is
required unless mandated by local health authority.

- The use of corticosteroids is not allowed for 10 days prior to initiation of therapy
(based upon 5 times the expected half-life of dexamethasone) except patients who are
taking steroids for physiological replacement. If alternative corticosteroid therapy
has been used, consultation with the sponsor medical monitor is required to determine
the washout period prior to initiating study treatment.

- Subjects with a condition requiring systemic treatment with either corticosteroids (>
10 mg daily prednisone equivalent) or other immunosuppressive medications within 14
days of study initiation. Inhaled or topical steroids, and adrenal replacement steroid
doses > 10 mg daily prednisone equivalent, are permitted in the absence of active
autoimmune disease.

- Subjects with history of life-threatening toxicity related to prior ipilimumab
adjuvant therapy except those that are unlikely to re-occur with standard
countermeasures (e.g. hormone replacement after adrenal crisis).

- Major surgical procedure, open biopsy (excluding skin cancer resection), or
significant traumatic injury within 14 days of initiating study drug (unless the wound
has healed) or anticipation of the need for major surgery during the study.

- Non-healing wound, ulcer, or bone fracture.

- Women who are breast-feeding or pregnant.

- Uncontrolled intercurrent illness (i.e., active infection >= grade 2) or concurrent
condition that, in the opinion of the Investigator, would interfere with the study
endpoints or the subject's ability to participate.

- Arterial or venous thrombotic or embolic events such as cerebrovascular accident
(including transient ischemic attacks), deep vein thrombosis or pulmonary embolism
within the 6 months before start of study medication (except for adequately treated
catheter-related venous thrombosis occurring more than 1 month before the start of
study medication).

- History of clinically significant cardiac disease or congestive heart failure > New
York Heart Association (NYHA) class 2. Subjects must not have unstable angina (anginal
symptoms at rest) or new-onset angina within the last 3 months or myocardial
infarction within the past 6 months.

- Investigational drug use within 14 days (or 5 half-lives, whichever is longer) of the
first dose of ipilimumab and pembrolizumab.

- Has a history of non-infectious pneumonitis that required steroids or current
pneumonitis.