Discontinuation of denosumab results in a rebound response of bone turnover markers, which rise above baseline at 3 months and remain elevated until reaching again baseline levels approximately 30 months after the last dose. Bone mineral density (BMD) gains are also lost and BMD values reach original baseline values after 1-2 years off-treatment.For the above reasons, current literature recommends that patients who discontinue denosumab should continue to receive either intravenous (iv) or oral (peros) bisphosphonate therapy for some time. The study aims to investigate changes in the BMD of the lumbar spine 12 months after transitioning from denosumab to oral alendronate 70 mg in a weekly effervescent tablet formulation