Sipuleucel-T and Stereotactic Ablative Body Radiation (SABR) for Metastatic Castrate-resistant Prostate Cancer (mCRPC)

Inclusion Criteria:

1. Biopsy proven prostate cancer
2. Patient must currently be on androgen deprivation or anti-androgen therapy with castrate levels of testosterone (\< 50ng/dl). Medical castration should continue until disease progression
3. Radiographic evidence of metastatic disease documented with bone scan or CT scan. Patients with any number of metastatic site are allowed to enroll. However, only up to six sites will be selected for SBRT treatment, at the discretion of the treating radiation oncologist.
4. PSA ≥ 5 ng/ml
5. Asymptomatic or minimally symptomatic patients1. Visual Analog Scale (VAS) ≤ 4;vNo narcotic use in the last 21 days
6. Adequate hematologic, renal, and liver function
7. Previous treatment with surgery, radiation or hormonal therapy is allowed.
8. Performance status ECOG 0 or 1.
9. Life expectancy of at least 6 months
10. Negative serology tests for human immunodeficiency virus (HIV) 1 and 2, human T cell lymphotropic virus (HTLV)-1, Hepatitis B and C.
11. Age ≥ 18 years.
12. Ability to understand and the willingness to sign a written informed consent

Exclusion Criteria:

1. Subjects must not have had more than two different regiments of chemotherapy previously or any chemotherapy within the past three months.
2. Subjects may not be receiving any other investigational agents for the treatment of prostate cancer.
3. Subjects with known brain metastases should be excluded from this clinical trial because of their poor prognosis and because they often develop progressive neurologic dysfunction that would confound the evaluation of neurologic and other adverse events.
4. Subjects with malignant pleural effusions and malignant ascites
5. Systemic corticosteroid use within past 28 days. Use of inhaled, intranasal, and topical steroids is acceptable.
6. Systemic immunosuppressive therapy in the past 28 days.
7. Use of any of the following within the past 28 days: Megestrol acetate (Megace®), diethyl stilbestrol (DES), or cyproterone acetate, Ketoconazole, high dose calcitriol \[1,25(OH)2VitD\] (i.e., \> 7.0 μg/week).
8. Inability to tolerate contrast dye for baseline CT imaging.
9. Initiation or discontinuation of biphosphonate use within past 28 days.
10. Subjects with pathologic long-bone fractures
11. Subjects with spinal cord compression
12. Paget's disease of bone.
13. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.