A Study of Pertuzumab in Participants With Prostate Cancer

An Open Label, Phase II, Multicenter Study to Evaluate the Efficacy and Safety of a Recombinant Humanized Antibody to HER2 (Pertuzumab) Administered Every 3 Weeks to Patients With Hormone-Refractory Prostate Cancer Who Have Not Been Treated With Chemotherapy

This study will evaluate the efficacy and safety of intravenous (IV) pertuzumab in participants with hormone-refractory prostate cancer who have had no previous chemotherapy. Participants will be enrolled in two stages, the first (Cohort A) at a lower 420-mg dose and the second (Cohort B) at a higher 1050-mg dose based upon observations in Cohort A. Up to 50 participants may enter either cohort, for a total enrollment between 46 and 73 participants across 9 study centers.

Inclusion Criteria:

• Adults greater than (>) 18 years of age
• Histologically documented adenocarcinoma of the prostate resistant to hormone therapy, progressed at 4 to 6 weeks following anti-androgen withdrawal
• Prostate-specific antigen (PSA) values at least 20 ng/mL among those with asymptomatic or mildly symptomatic disease
• Karnofsky performance status (KPS) at least 80 percent (%)
• Castrate testosterone less than (<) 50 ng/dL
• Life expectancy at least 12 weeks
• Left ventricular ejection fraction (LVEF) at least 50%
• Adequate hematologic, hepatic, and renal function

Exclusion Criteria:

• Prior chemotherapy, radionucleotide therapy, or immunotherapy for prostate cancer
• Systemic corticosteroids within 1 month prior to Screening
• Bisphosphonates within 6 months, narcotic analgesics within 2 weeks, or any investigational agent with 28 days of study drug
• Prior cumulative doxorubicin dose of > 360 mg/m^2 or equivalent
• Central nervous system (CNS) or pulmonary metastases
• Other malignancies, except adequately treated basal or squamous cell skin cancer
• Significant cardiovascular disease
• Active/uncontrolled concurrent illness or infection
• Major surgery or traumatic injury within 4 weeks of study drug