A Pilot Study to Test the Feasibility and Immunologic Impact of Sipuleucel-T (Provenge) Administered With or Without Anti-PD-1 mAb (CT-011) and Low Dose Cyclophosphamide in Men With Advanced Castrate-Resistant Prostate Cancer

Inclusion Criteria

- INCLUSION CRITERIA:

Patients must have histopathological documentation of prostate cancer prior to starting
this study.

Patients must have metastatic progressive castrate-resistant prostate cancer defined as
progressive disease (see below) despite surgical castration or ongoing use of
gonadotropin-releasing hormone agonists with confirmed castrate levels of testosterone.
Criteria of progression for trial eligibility are defined from the Prostate Cancer
Clinical Trials Working Group-253. Clinically progressive prostate cancer must be
evidenced and documented by any of the following parameters:

1. Two consecutively rising PSA values at a minimum of 1-week intervals (2.0 ng/mL is
the minimum starting value for PSA)

2. Appearance of one or more new lesions on bone scans

3. Progressive measurable disease by RECIST 1.1

Patients on flutamide for at least 6 months must have disease progression at least 4
weeks after withdrawal. Patients on bicalutamide or nilutamide for at least 6 months
must have progression at least 6 weeks after withdrawal.2.1.1.4 Performance Status:
ECOG 0-1 or Karnofsky 80-100% (asymptomatic or minimally symptomatic from metastatic
disease).

No previous chemotherapy use.

No therapeutic immunosuppression or immunomodulation altering bone marrow function
within 6 weeks prior to study entry e.g. G-CSF, GM-CSF, EPO, prednisone etc.

Must have adequate:

- Bone marrow function: Absolute neutrophil count (ANC) greater than or equal to
1,500/mcl. Platelets greater than or equal to 100,000/mcl.

- Renal function: Creatinine less than or equal to 1.5 times institutional upper
limit normal (ULN)

- Hepatic function: Bilirubin less than or equal to 1.5 x ULN (CTCAE v4.0 grade 1)
except patients with Gilbert's disease (up to 5.0 mg/dL). SGOT and alkaline
phosphatase less than or equal to 2.5 x ULN.

- Normal Cardiac function: ECG with no evidence of arrhythmia, conduction
abnormality or ischemia. No active coronary artery disease; no New York Heart
Association class II, III or IV disease; no arrhythmia requiring treatment.

Must willing and able to sign an informed consent document that explains the
neoplastic nature of the disease, the procedures to be followed, the experimental
nature of the treatment, alternative treatment and potential risks and toxicities.

EXCLUSION CRITERIA:

Concurrent treatment with any other cancer therapies including radiation (except
palliative radiation therapy for bone metastases), chemotherapy or other
investigational agent(s). Androgen suppression therapy will be allowed.

History of a second active malignancy in the last 2 years other than non-melanoma
skin cancers.

Patients who have active or history of autoimmune disease/symptom/conditions
including: type I diabetes, rheumatoid arthritis, systemic lupus erythematosus (SLE),
ulcerative colitis, Crohn's Disease, multiple sclerosis (MS), ankylosing spondylitis.
Type II diabetes mellitus, vitiligo or stable hypothyroidism are not considered
exclusion criteria.

Patients being chronically treated with immunosuppressive drugs such as cyclosporin,
adrenocorticotropic hormone (ACTH).

Concurrent use of systemic glucocorticoids within 4 weeks prior to trial entry

Patients who have acquired, hereditary, or congenital immunodeficiencies including
cellular immunodeficiencies, hypogammaglobulinemia and dysgammaglobulinemia.

CNS, lung, or liver metastasis, because of the poor prognosis, and potential
inability to meet study endpoints.

Serious active infection at the time of pre-study screening.

Positive HIV or Hepatitis C antibodies or Hepatitis B anti-core antibodies, because
immunotherapies rely on intact immune systems, and toxicities may be exacerbated by
the presence of infection.