Study of Ruxolitinib (INCB018424) Administered Orally to Patients With Androgen Independent Metastatic Prostate Cancer

Inclusion Criteria:

- Diagnosed with radiographically-documented metastatic prostate cancer that has
progressed while receiving androgen-suppressive therapy in the form of a bilateral
orchiectomy or Gonadotropin-Releasing Hormone (GnRH) agonist (eg, leuprolide,
goserelin).

- Patients must demonstrate evidence of progressive disease based on 1 of the following
criteria: 1) Progressive measurable disease, or 2) Progressive rise in
prostate-specific antigen (PSA) level (2 consecutive rises from a prior reference
level), or 3) Development of new lesions on bone scan.

- If receiving a GnRH agonist as primary hormonal therapy, the serum testosterone level
must be ≤ 50 ng/mL.

- Must have received and progressed during or following 1 prior chemotherapy regimen for
metastatic disease (not including an anti-androgen or ketoconazole); or, must have
discontinued prior systemic therapy because of poor tolerance or other adverse
effects; or, must have refused chemotherapy treatment. Patients having undergone more
than 1 prior chemotherapy regimen may be admitted at the discretion of the sponsor.

- Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.

- Baseline serum PSA level of ≥ 10 ng/mL

Exclusion Criteria:

- Received any anti-cancer medications in the 30 days before receiving their first dose
of study medication except for GnRH agonists and bisphosphonates.

- Any unresolved toxicity greater than or equal to Grade 2 from previous anti-cancer
therapy, except for stable chronic toxicities not expected to resolve, such as
peripheral neurotoxicity.