Inclusion Criteria:

- Previously randomized in Dendreon's P-11 study (NCT00779402) and received at least
one infusion of sipuleucel-T

- Radiologic evidence of metastasis

- Castrate resistant prostate cancer. Subjects must have current or historical
evidence of disease progression concomitant with surgical or medical castration, as
demonstrated by PSA progression OR progression of measurable disease OR progression
of non-measurable disease

- Castrate level of testosterone (< 50 ng/dL) achieved via medical or surgical
castration

- Adequate hematologic function

Exclusion Criteria:

- Eastern Cooperative Oncology Group (ECOG) performance status > 2

- Treatment with chemotherapy within 3 months prior to registration

- Treatment with systemic corticosteroids, external beam radiation therapy, or any
investigational product for prostate cancer within 28 days prior to registration

- Current or imminent pathologic long-bone fracture

- Known malignancies other than prostate cancer that are likely to require treatment
within 6 months following registration

- A requirement for systemic immunosuppressive therapy for any reason

- A history of allergic reactions attributed to compounds of similar chemical or
biologic composition to sipuleucel-T or GM-CSF

- Any infection requiring antibiotic therapy or causing fever within 1 week prior to
registration

- Any surgery requiring general anesthetic within 28 days prior to registration