The purpose of this study is to compare the effect of an investigational drug used intravenously and placebo administered every three months for one year, on bone loss associated with initial androgen deprivation) in men with prostate cancer without metastasis. In order to participate in this trial male patients must be 18 years of age or older and have been diagnosed with prostate cancer without metastasis and within one year of starting their androgen deprivation therapy at the day of randomization onto this trial. In addition, patients who have undergone a recent orchiectomy (or"ke-ek'te-me) (removal of one or two testes) are eligible to participate. Patients who received any prior bisphosphonate therapy or prior treatment with systemic corticosteroids within in the past 12 months are not eligible to participate. Also patients who are receiving treatment for osteoporosis are not eligible to participate. Inclusion into this clinical trial with this investigational drug is based on the protocol entry criteria and evaluation from a participating trial investigator.