Denosumab discontinuation is associated with a rebound effect manifesting by an increased risk of multiple spontaneous vertebral fractures. The purpose of this review is to (1) better characterize this risk and (2) find solutions to avoid it.
In the absence of a potent bisphosphonate prescription at denosumab discontinuation, the frequency of multiple vertebral fractures is common or frequent (≥ 1/100 and < 1/10). In five recent case series, the median number of vertebral fractures was 5 within 7 to 20 months (median 11) after the last denosumab injection. Prescribing bisphosphonate before starting denosumab and/or after stopping denosumab may reduce this risk. However, only small case series have evaluated these strategies. After the second denosumab dose, there is a rebound effect with an increased risk of multiple vertebral fractures. A potent bisphosphonate prescribed at denosumab discontinuation could reduce this risk. As denosumab discontinuation is characterized by many uncertainties, denosumab is a second-line treatment for osteoporosis. Studies are urgently needed to define the management of denosumab discontinuation.