Phase II Study of Sipuleucel-T and Indoximod for Patients With Refractory Metastatic Prostate Cancer

Inclusion Criteria:

Histologically documented adenocarcinoma of the prostate with metastatic disease as evidenced by soft tissue and/or bony metastases on baseline computed tomography (CT) scan of the abdomen and pelvis and/or bone scan

Castration-resistant based on a current or historical evidence of disease progression despite surgical or medical castration as demonstrated by one or more of the following:

PSA progression (defined as two consecutive prostate specific antigen (PSA) measurements at least 14 days apart ≥ 2.0 ng/ml and ≥ 50% above the minimum PSA during castration therapy or above pre-treatment value if no response)
progression of measurable disease based on Response Evaluation Criteria In Solid Tumors (RECIST) criteria (≥ 50% increase in the sum of the cross products of all measurable lesions or the development of any new lesions
progression of non-measureable disease
Serum PSA ≥ 2.0 ng/ml at study enrollment
Castration levels of testosterone defined as ≤ 30 ng/dL at study enrollment. Must be at least 3 months from surgical castration or must have received medical castration therapy for at least 3 months and be receiving such therapy at the time of confirmed disease progression
Asymptomatic or minimally symptomatic disease as demonstrated by Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1 and no need for opiate pain medications to control pain/symptoms
Age 18 years and old

Adequate bone marrow, renal and hepatic function within 14 days of study enrollment defined as:

Bone marrow: WBC > 3,000/uL; absolute neutrophil count > 1,500/uL; platelets > 100,000/uL
Renal: creatinine within institutional upper limit of normal (ULN) OR creatinine clearance > 60 mL/min/1.73 m2 for patients with creatinine levels above ULN
Hepatic: total bilirubin < 1.5 X institutional ULN; aspartate aminotransferase (AST ((SGOT)) and alanine aminotransferase (ALT((SGPT)) < 2.5 X institutional ULN

Exclusion Criteria:

Chronic steroid dependence (should stop all steroid supplementation 4 weeks prior to enrollment)
Human immunodeficiency virus (HIV)-positive patients and those with other acquired/inherited immunodeficiency
History of gastrointestinal disease causing malabsorption or obstruction such as, but not limited to Crohn's disease, celiac sprue, tropical sprue, bacterial overgrowth/blind loop syndrome, gastric bypass surgery, strictures, adhesions, achalasia, bowel obstruction, or extensive small bowel resection
Inability to take medications by mouth
History of allergic reactions attributed to compounds of similar chemical or biologic composition
Active autoimmune disease, chronic inflammatory condition, conditions requiring concurrent use of any systemic immunosuppressants or steroids. Mild-intermittent asthma requiring only occasional beta-agonist inhaler use or mild localized eczema will not be excluded.
Previous allo-transplant of any kind
History of prior treatment with anti-CTLA4 blocking antibody