Patient description: The patient is a 53-year-old man complaining of frequent headaches, generalized bone pain and difficulty chewing that started 6 years ago and is getting worse. Examination shows bilateral swellings around the molars. The swellings have increased since his last examination. Several extraoral lesions of the head and face are detected. The swellings are non-tender and attached to the underlying bone. Further evaluation shows increased uptake of radioactive substance as well as an increase in urinary pyridinoline. The serum alkaline phosphatase is 300 IU/L (the normal range is 44- 147 IU/L). The patient's sister had the same problems. She was diagnosed with Paget's disease of bone when she was 52 years old. The diagnosis of Paget's Disease of Bone is confirmed and Bisphosphonate will be started as first-line therapy.

Clinical trial eligibility criteria: eligible ages (years): 50.0-85.0,  Osteoporosis, Postmenopausal Osteoporosis Osteoporosis Vertebral Osteoporosis Risk Osteoporosis Fracture Osteoporosis Localized to Spine Osteoporosis, Age-Related Osteoporosis Senile Osteoporosis of Vertebrae Subject must meet all of the following to be eligible to participate in this study: 1. The subject is a healthy ambulatory postmenopausal female from 50 to 85 years of age (inclusive) with osteoporosis. 2. The subject has been postmenopausal for at least 5 years. Postmenopausal status will be established by a history of amenorrhea for at least 5 years and by an elevated follicle stimulating hormone (FSH) value of ≥ 30 IU/L. 3. The subject has a BMD T-score ≤ -2.5 at the lumbar spine (L1-L4) or hip (femoral neck or total hip) by DXA or lumbar spine or hip BMD T-score ≤ -2.0 with a history of low trauma vertebral, forearm, humerus, sacral, pelvic, hip, femoral, or tibial fracture sustained within 5 years prior to enrollment. These fractures must be documented by radiograph or hospital report. 4. The subject is in good general health as determined by medical history and physical examination (including vital signs), has a body mass index (BMI) of 18.5 to 33, inclusive, and is without evidence of clinically significant abnormality in the opinion of the Investigator. 5. The subject has serum calcium (albumin-corrected), PTH (1-84), phosphorus, and alkaline phosphatase levels all within the normal range during the Screening Period. Any patient with an elevated alkaline phosphatase value, and who meets all other entry is required to have a normal bone-specific alkaline phosphatase result to be enrolled. 6. The subject has serum 25-hydroxyvitamin D values ≥ 20 ng/mL and within the normal range. Patients with serum 25-hydroxyvitamin D levels < 20 ng/ml may be treated with vitamin D3 and re-tested once. 7. The subject's resting 12-lead electrocardiogram (ECG) obtained during screening shows no clinically significant abnormality. 8. The subject has read, understood, and signed the written informed consent form  Subjects with any of the following characteristics are not eligible to participate in the study: 1. Presence of abnormalities of the lumbar spine that would prohibit assessment of lumbar spine BMD, defined as having at least 2 radiologically evaluable vertebrae within L1-L4. 2. Unevaluable hip BMD or patients who have undergone bilateral hip replacement (unilateral hip replacement is acceptable). 3. History of bone disorders (eg, Paget's disease) other than postmenopausal osteoporosis. 4. Clinically significant abnormality of serum hemoglobin, hematocrit, white blood cells (WBC) and platelets, coagulation, or usual serum chemistry: electrolytes, renal function, liver function and serum proteins. 5. Unexplained elevation of serum alkaline phosphatase. 6. History of radiotherapy (radiation therapy), other than radioiodine. 7. History of bleeding disorder that would preclude a bone biopsy, in the opinion of the Investigator. 8. History of chronic or recurrent renal, hepatic, pulmonary, allergic, cardiovascular, gastrointestinal, endocrine, central nervous system, hematologic or metabolic diseases, or immunologic, emotional and/or psychiatric disturbances to a degree that would interfere with the interpretation of study data or compromise the safety of the patient. 9. History of Cushing's disease, hyperthyroidism, hypo or hyperparathyroidism, or malabsorptive syndromes within the past year. 10. History of significantly impaired renal function (serum creatinine > 177 µmol/L or > 2.0 mg/dL). If the serum creatinine is > 1.5 and ≤ 2.0 mg/dL, the calculated creatinine clearance (Cockcroft-Gault) must be ≥ 30 mL/min. 11. History of any cancer within the past 5 years (other than basal cell or squamous cell cancer of the skin). 12. History of osteosarcoma at any time or a history of hereditary disorders which could predispose the patient to osteosarcoma. 13. History of nephrolithiasis or urolithiasis within the past five years. 14. Subjects known to be positive for hepatitis B, hepatitis C, human immunodeficiency virus infection (HIV-1 or HIV-2). Testing is not required in the absence of clinical signs and symptoms suggestive of HIV infection or acute or chronic hepatitis