Nivolumab, Ipilimumab and Chemoradiation in Treating Patients With Resectable Gastric Cancer

PRIMARY OBJECTIVES:

I. To evaluate the safety and toxicity profile of intravenous nivolumab in combination with
ipilimumab after standard chemotherapy and followed by intravenous nivolumab in combination
with fluoropyrimidine and intensity-modulated radiation therapy (IMRT) for the treatment of
localized gastroesophageal junction (GEJ) and/or gastric cancer.

SECONDARY OBJECTIVES:

I. To assess the efficacy of double checkpoint inhibition (nivolumab + ipilimumab) followed
by nivolumab plus chemoradiation.

II. To assess the overall safety and tolerability of adjuvant nivolumab in subjects with
resected GEJ or gastric cancer.

III. To evaluate disease free survival (DFS).

IV. To explore changes in tumor stroma profile before and after immunotherapy and radiation
therapy.

V. To bank tumor and blood specimen for future correlative analysis, including, but not
limited to, biomarker analysis.

OUTLINE:

INDUCTION CHEMOTHERAPY: Patients receive oxaliplatin intravenously (IV) over 2 hours and
fluorouracil IV over 48 hours on day 1. Treatment repeats every 14 days for up to 4 courses
in the absence of disease progression or unacceptable toxicity.

Patients receive nivolumab IV over 30 minutes and ipilimumab IV over 30 minutes on day 1.
Treatment with nivolumab repeats every 2 weeks for up to 6 courses in the absence of disease
progression or unacceptable toxicity. Beginning course 4, patients also receive fluorouracil
IV continuously for 5 days per week and undergo 25 fractions of IMRT for 5 weeks. Patients
undergo surgical resection 5-7 weeks after completing radiation therapy.

Within 8-12 weeks post-surgery, patients with residual disease may receive nivolumab IV over
30 minutes on day 1. Treatment repeats every 2 weeks for 8 courses (16 weeks) then every 4
weeks for up to 2 courses in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 30 and 84 days, every 12
weeks for 2 years, then every 6-12 months for up to 3 years.

Inclusion Criteria:

- Subjects must have signed and dated an Institutional Review Board (IRB)/Independent
Ethics Committee (IEC) 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 tests and other requirements of the study.

- All subjects must have localized/eligible for surgery gastric cancer (GC) or GEJ
carcinoma type III, with negative peritoneal washing. Subjects must have
histologically confirmed predominant adenocarcinoma. The documentation of GEJ
involvement can include biopsy, endoscopy, or imaging.

- Subject must be previously untreated with systemic treatment (including HER 2
inhibitors) given as primary therapy for advanced or metastatic disease. No prior
neoadjuvant chemotherapy, immunotherapy, radiotherapy and/or chemoradiotherapy are
permitted.

- Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.

- Absolute neutrophil count (ANC) >= 1,500/mcL (within 28 days of treatment initiation).

- Platelets >=100,000/mcL (within 28 days of treatment initiation).

- Hemoglobin >= 9 g/dL or > 5.6 mmol/L; if patient is not actively bleeding and has
hemoglobin of < 9g/dL, patient can receive blood transfusion to increase hemoglobin to
>= 9g/dL (within 28 days of treatment initiation).

- Serum creatinine =< 1.5 X upper limit of normal (ULN) OR measured or calculated
creatinine clearance (glomerular filtration rate [GFR] can also be used in place of
creatinine or creatinine clearance [CrCL]) > 60 mL/min for subjects with creatinine
levels > 1.5 x institutional ULN (measured via 24-hour urine collection) (within 28
days of treatment initiation). Creatinine clearance should be calculated per
institutional standard.

- Serum total bilirubin =< 1.5 X ULN (1.5 mg/dL or 25.65 umol/L) OR direct bilirubin <
ULN for subjects with total bilirubin levels < 1.5 X ULN. Except patients with
Gilbert's disease (< 3 X ULN) (within 28 days of treatment initiation).

- Aspartate aminotransferase AST (serum glutamic oxaloacetic transaminase [SGOT]) and
alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) =< 2.5 X
ULN OR < 5 X ULN for subjects with liver metastases (within 28 days of treatment
initiation).

- Albumin >= 3 mg/dL (within 28 days of treatment initiation).

- Prothrombin Time (PT) < 1.5 X ULN unless subject is receiving anticoagulant therapy as
long as PT or partial thromboplastin time PTT is within therapeutic range of intended
use of anticoagulants. Activated partial thromboplastin Time (aPTT) < 1.5 X ULN unless
subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic
range of intended use of anticoagulants (within 28 days of treatment initiation).

- Women of childbearing potential (WOCBP) must have a negative serum or urine pregnancy
test (minimum sensitivity 25 IU/L or equivalent units of human chorionic gonadotropin
[HCG]) within 24 hours prior to the start of study drug. Women must not be
breastfeeding.

- Prior to chemotherapy and immunotherapy, WOCBP must agree to follow instructions for
method(s) of contraception for the duration of study treatment with nivolumab and 5
months after the last dose of study treatment (i.e. 30 days (duration of ovulatory
cycle plus the time required for the investigational drug to undergo approximately
five half-lives).

- Males who are sexually active with WOCBP must agree to follow instructions for methods
of contraception for the duration of study treatment with nivolumab and 7 months after
the last dose of study treatment (i.e. 90 days (duration of sperm turnover) plus the
time required for the investigational drug to undergo approximately five half-lives).
In addition, male subjects must be willing to refrain from sperm donation during this
time.

Exclusion Criteria:

- Participants with an active, known or suspected autoimmune disease. Participants 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.

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

- Known history of positive test for human immunodeficiency virus (HIV) or known
acquired immunodeficiency syndrome (AIDS).

- NOTE: Testing for HIV must be performed at sites where mandated locally.

- White blood cell (WBC) < 2000/uL.

- Any positive test result for hepatitis B virus or hepatitis C virus indicating
presence of virus, e.g. hepatitis B surface antigen (HBsAg Australia antigen)
positive, or hepatitis C antibody (anti-HCV) positive (except if hepatitis C virus-
ribonucleic acid [HCV-RNA] negative).

- History of allergy or hypersensitivity to study drug components.

- Prior malignancy active within the previous 3 years except for locally curable cancers
that have been apparently cured, such as basal or squamous cell skin cancer,
superficial bladder cancer, or carcinoma in situ of the prostate, cervix, or breast.

- Patients with serious or uncontrolled medical disorders.

- Prior treatment with an anti-PD-1, anti-PD-L1, anti-PD-L2, or anti-CTLA-4 antibody, or
any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint
pathways.