AIM: To evaluate the efficacy and safety of Denosumab (Prolia), a first-line 
osteoporosis (OP) medication that is a fully human monoclonal antibody to the 
receptor activator of nuclear factor xB ligand (RANKL), within an open-label 
observational study.
SUBJECTS AND METHODS: Patients aged 50 years or older with postmenopausal OP, 
who were treated with Prolia in clinical practice, were examined. The 
concentrations of the bone resorption (BR) marker of C-terminal telopeptide and 
other laboratory indicators (total serum calcium, total alkaline phosphatase, 
and creatinine) were measured following 3 months. Adverse drug reactions were 
recorded.
RESULTS: Three months after initiation of the investigation, there was a 
significant decrease in the BR marker C-terminal telopeptide (by 89%; p<0.0001). 
There were rare adverse reactions: hypocalcemia in 3 (5.9%) patients, 
arthralgias in 2 (3.9%), and eczema in 1 (1.9%). There were neither serious 
adverse events nor study withdrawal cases.
CONCLUSION: The preliminary results of the open-label study of Prolia in 
postmenopausal OP suggest that the significantly lower BR activity determines 
the efficacy of this drug and its high safety.