Calcium-41 (41Ca) Chloride Aqueous Solution in Diagnosing Patients With Prostate Cancer and Bone Metastasis

OBJECTIVES:

Primary

- To measure the pharmacokinetics of a single oral dose of calcium-41 (41Ca) chloride
aqueous solution (^41Ca) over 18 months in patients with hormone-refractory prostate
cancer and bone metastasis.

- To correlate the ^41Ca-tracer kinetics with time to disease progression,
skeletal-related events, and death.

Secondary

- To correlate modulations in baseline urinary ^41Ca clearance with changes in clinically
relevant disease parameters, including isotope bone scan data and PSA.

- To combine bone turnover assessments with ^41Ca and collagen/bone cell biomarkers with
clinical imaging techniques, especially isotope bone scans, to provide improved
stratification of disease stage.

OUTLINE: Patients receive oral calcium-41 (41Ca) chloride aqueous solution (^41Ca) on day 1.
Some patients also receive oral calcium-46 (46Ca) chloride aqueous solution (^46Ca).

Urine and blood specimens are collected periodically for 18 months. Blood samples are assayed
for bone collagen residues, bone alkaline phosphatase, and PSA. Urine specimens are assessed
for ^41Ca/Ca. Isotope bone scintigraphy is use to measure radioactivity.

After completion of study treatment, patients are followed up periodically for 3 years.

Eligibility Criteria

- Histologically or cytologically confirmed prostate cancer with a Gleason score
available or interpretable

- Prostate cancer deemed to be hormone refractory or androgen independent within the
past 12 months

- Evidence of bony metastasis

- Either be receiving bisphosphonate therapy or have received a bisphosphonate within
the last 18 months. Participants who are on not on bisphosphonate therapy nor have
received it within the last 18 months should currently be on Denosumab therapy. All
other anti-cancer therapies are allowed.

- Age >18 years

- ECOG performance status 0-2 (Karnofsky >50%).

- Life expectancy of 6 months or greater.

- Investigators are encouraged to follow good medical practice to assure that all
participants have adequate hematologic, hepatic, and renal function.

- Recent or planned isotope bone scan, within 12 months prior to enrollment.

- Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria

- Participants will be excluded who have experienced a severe skeletal related event
(SRE)within the past 3 months. For this study, an SRE consists of any of the
following: palliative radiotherapy to bone, pathologic fractures, spinal cord
compression, hypercalcemia of malignancy, and surgery to bone to treat or prevent a
fracture.

- Uncontrolled intercurrent illness including, but not limited to ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, interstitial lung disease, chronic kidney disease, hyperthyroidism, or
psychiatric illness/social situations that would limit compliance with study
requirements.

- Corrected serum calcium <8.0 mg/dL (2.0 mmol/L) or ≥12.0 mg/dL (3.0 mmol/L)