PET/MR Assessment of Sipuleucel T Treatment for Metastatic Castration Resistant Prostate Cancer

Multimodality Imaging Assessment of Sipuleucel T Treatment and in Vivo Immune Response of Metastatic Castration Resistant Prostate Cancer Patients

This study intents to provide an initial evaluation of the utility of positron emission tomography and magnetic resonance (PET/MR) imaging measures for the prediction of immunological response to Sipuleucel T (SipT) therapy.

Recent studies of treatments of prostate cancer through stimulation of adaptive immune response have indicated the linear measurements by computed tomography (CT) and nuclear scans used to assess tumor response by Response Evaluation Criteria in Solid Tumors (RECIST) were inadequate and the value of progression-free survival (PFS) as a predictive surrogate endpoint of survival was lost.

The objective of this study is to provide an initial evaluation of the utility of PET/MR imaging measures for the prediction of immunological response to SipT therapy. Investigators expect to identify an"imaging-signature" of response to SipT based on changes in metabolism, perfusion, oxygenation and cellularity of metastasis and its correlation with immunological and clinical response. This approach will help elucidate the mechanism of activity and dynamics of immune antitumor responses to SipT in vivo and to identify new parameters of tumor response and predictive value than current RECIST and PFS standards.

Inclusion Criteria:

• Men ≥ 18 years of age
• History of prostate cancer treated with androgen deprivation
• Serum Testosterone levels <50 ng/mL
• Established asymptomatic or minimally symptomatic metastasis
• Eastern Cooperative Oncology Group (ECOG) performance status≤2
• Accept the terms of the imaging modalities and performance at pre-established time points as described in the protocol and consent
• Accept the terms for immune-monitoring blood drawing and performance at pre-established time points as described in the protocol and consent
• Patients that are on steroids (prednisone up to 10mg daily or hydrocortisone 20 mg daily) alone or in combination with Zytega or ketoconazole prior to enrollment are eligible
• Patients that are on steroids for an underlying chronic condition are eligible. (prednisone up to 10 mg daily, dexamethasone <2 mg daily or fludrocortisone 0.1 mg daily orally)

Exclusion Criteria:

• Chemotherapy or radiation therapy treatment within 21 days of Sipuleucel-T
• ECOG performance status >2
• Prior treatment with Sipuleucel-T
• Patients with a history of another primary malignancy within the last 2 years that was not curatively treated, excluding basal or squamous cell carcinoma of the skin
• Patients with known positivity for human immunodeficiency virus (HIV) or hepatitis C; baseline testing for HIV and hepatitis C is not required
• Patients with any significant history of non-compliance to medical regimens or with inability to grant a reliable informed consent
• Active spinal cord compression.