Open- Label Trial of Sipuleucel-T Administered to Active Surveillance Patients for Newly Diagnosed Prostate Cancer

Inclusion Criteria:

1. Age is ≥ 18 years

2. Written informed consent provided prior to the initiation of study procedures

3. Histologically proven adenocarcinoma of the prostate initially diagnosed ≤12months of Screening. All biopsy slides with participant information redactedmust be submitted for blinded independent central review (BICR).

4. Prostate cancer diagnosis determined by BICR as one of the following: 4a. ISUPGrade Group 1 with 3 or more cores positive from a systematic (≥10 cores)biopsy 4b. ISUP Grade Group 1 with ≥ 1 core positive with ≥50% cancerinvolvement from a systematic (≥10 cores) biopsy 4c. ISUP Grade Group 1 from 3or more positive cores from any combination of cores from a systematic (≥10cores) biopsy and MRI targeted biopsy (note: multiple cores from each MRItargeted lesion will count as 1 core) 4d. ISUP Grade Group 1 from a negativesystematic (≥10 cores) biopsy and an MRI targeted core positive with ≥50%cancer involvement 4e. ISUP Grade Group 2 from a systematic (≥10 cores) biopsywith <50% of the total number of any cores positive for cancer 4f. ISUP GradeGroup 2 from a negative systematic (≥10 cores) biopsy and MRI targeted core(s)positive for Gleason 3+4 (see note below) 4g. ISUP Grade Group 2 from anycombination of cores from a systematic (≥10 cores) biopsy and MRI targetedbiopsy (see note below)

Note for 4f and 4g: the total number of positive cores must be <50% of total cores from both the systematic biopsy and MRI targeted lesions; each MRI targeted lesion, irrespective of multiple positive cores, will each count as 1 core for the total number of positive cores, e.g., 4 targeted lesions with 2 positive cores each will only add 4 to the total core count.

5. Participant consents to standard of care for biopsy frequency of 2 on-studyprostate biopsies and to provide biopsy tissue for study endpoint analysis.

6. Estimated life expectancy ≥ 10 years

7. Candidate for primary curative therapy (e.g., surgery or radiation) if prostatecancer progression occurs

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

9. Adequate baseline hematologic, renal, and liver function tests as evidenced bylaboratory test results within the following ranges ≤30 days prior torandomization White blood cell (WBC) count ≥ 3.0 x 10^6 cells/mL Absoluteneutrophil count (ANC) ≥ 1.5 x 10^6 cells/mL Platelet count ≥ 1.0 x10^5cells/uL Hemoglobin (Hgb) ≥ 10.0 g/dL Creatinine ≤ 1.5 mg/dL Total bilirubin ≤ 1.5 x upper limit of normal (ULN) Alanine aminotransferase (ALT) ≤ 2.0 x ULNAspartate aminotransferase (AST) ≤ 2.0 x ULN

Exclusion Criteria:

1. Former therapy for prostate cancer (local or systemic)

2. Any previous prostatic surgical procedure that significantly changes theanatomy of prostate (at the discretion of sponsor's Medical Monitor)

3. Any investigational product received for prostate cancer

4. Prostate biopsy specimen reveals neuroendocrine or small cell features

5. Primary Gleason score is ≥ 4 or any Gleason pattern 5

6. Any evidence of locally advanced, regional or metastatic disease, includingregional and distant lymph node enlargement (Nodes ≥1.5 cm in the short axisare considered pathologic and measurable)

7. A history of a cerebrovascular event (CVE) or transient ischemic attack (TIA)

8. Participant has used a 5-alpha-reductase inhibitor (e.g., finasteride ordutasteride) continuously for ≥ 6 months and within 6 months prior to studyScreening

9. Participant has a history of any other stage I-IV malignancy, except for basalor squamous cell skin cancer. The Participant must be disease free and off anymalignancy-related treatment for at least 5 years.

10. Participant has prior use within 30 days of study Screening of any herbal,dietary, or alternative anti-cancer treatment or product, such as PC-SPES (orPC-x product), saw palmetto, ketoconazole, an estrogen-containingnutraceutical, or high dose calcitriol (>0.5 μg/day). The Investigator willconsider herbal therapies on a case-by-case basis to determine whether theyfall into the category of prohibited medications based on their potential forhormonal or anti-cancer or anti-cancer properties.

11. Need for systemic chronic immunosuppressive therapy (e.g., anti-tumor necrosisfactor alpha monoclonal antibodies, glucocorticoids)

12. Uncontrolled, concurrent illness including, but not limited to the following:ongoing or active infection (bacterial, viral, or fungal), symptomaticcongestive heart failure (New York Classification III-IV) or unstable anginapectoris within the last 6 months, or psychiatric illness that would limitcompliance with study requirements as well as any condition that would precludea participant from undergoing leukapheresis (e.g., within the previous 6months: myocardial infarction, interventional cardiology procedure such asangioplasty or stent placement, pulmonary embolism or deep vein thrombosis).

13. Hypogonadal (T <175 ng/dL) or on continuous testosterone replacement therapy

14. Positive serology for HIV-1, HIV-2 or human T-lymphotropic virus (HTLV)-1,HTLV-2

15. Active hepatitis B or C

16. Any medical intervention, any other condition, or any other circumstance which,in the opinion of the investigator or the sponsor's Medical Monitor, couldcompromise adherence with study requirements or otherwise compromise thestudy's objectives.