Conditions: Metastatic Prostate Cancer
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 63
Healthy volunteers: no

Brief summary:
Risedronate is an orally administered pyridinyl bisphosphonate that is 36 times more potent than pamidronate and 72 times more potent than clodronate. Four randomized, double-blind trials have been carried out in patients with postmenopausal osteoporosis. In 2 of these studies, vertebral fracture incidence was reduced by a daily dose of 5 mg risedronate by up to 65% and 49% relative to placebo after 1 and 3 years, respectively. In these trials, risedronate improved lumbar spine, femoral neck, and femoral trochanter bone mineral density (BMD) at 6 months. In addition, preclinical studies have shown that risedronate is more potent than pamidronate and clodronate in inhibiting adhesion of prostate cancer cells to bone and preventing tumor cell invasion. The incidence of osteoporosis in prostate cancer patients has been well established; therefore, it is advantageous to assess the efficacy of oral bisphosphonate therapy.

Detailed description:
OUTLINE: This is a randomized, placebo-controlled, double-blind, multicenter, 2 arm study.

The study population will consist of prostate cancer patients with metastatic bone disease for whom androgen-deprivation therapy is planned. After stratification based on the patient's age, performance status, and severity of metastatic disease, the patients will be randomized at a 1:1 ratio to the following treatment arms:

* Daily oral risedronate combined with androgen deprivation
* Daily oral placebo combined with androgen deprivation

Initial clinical evaluation will be performed during the 2-week screening period. While patients receive per-protocol treatment, study assessments will be performed every 4 weeks during the first 3 months, and every 12 weeks thereafter.

Performance Status: Eastern Cooperative Oncology Group (ECOG) 0 to 2

Life Expectancy: At least 12 weeks

Hematopoietic:

* Absolute neutrophil count (ANC) \> 1,000/mm3
* Platelet count \> 100,000/mm3
* international normalized ratio (INR) \< 1.5 x upper limit of normal unless on therapeutic anticoagulation
* Partial thromboplastin time (PTT) \< 1.5 x upper limit of normal unless on therapeutic anticoagulation

Hepatic:

* Bilirubin \< 1.5 mg/dL
* Alanine transaminase (ALT) \< 2.5 x upper limit of normal

Renal:

* Creatinine clearance of \> 30 mL/min (by Cockcroft-Gault)

Cardiovascular:

* No significant history of uncontrolled cardiac disease (i.e., uncontrolled hypertension, unstable angina, and congestive heart failure).

Pulmonary:

* Not specified

Calcium:

* Corrected serum calcium = (4.0 g/dL - actual albumin g/dL)x 0.8 + serum calcium

Arms:
arm 1: Daily oral risedronate combined with androgen deprivation arm 2: daily oral placebo combined with androgen deprivation

Interventions: intervention 1: Risedronate intervention 2: Placebo
Intervention descriptions: intervention 1: Daily oral risedronate combined with androgen deprivation intervention 2: Daily oral placebo combined with androgen deprivation

Protocol document: