The why and how of sequential and combination therapy in osteoporosis. A review of the current evidence

It is now well recognized that over the lifetime of a patient with osteoporosis, more than one medication will be needed to treat the disease and to decrease fracture risk. Though current gaps in osteoporosis therapy can be potentially mitigated with sequential and combination regimens, how to move seamlessly amongst the multiple treatments currently available for osteoporosis for sustained efficacy is still unclear. Data from recent studies show that an anabolic agent such as teriparatide or romosozumab followed by an antiresorptive affords maximal gain in BMD and possibly better and earlier fracture risk reduction compared to a regimen which follows the opposite sequence. Sequentially moving to a bisphosphonate such as alendronate from an anabolic agent such as abaloparatide has also been shown to preserve the fracture reduction benefits seen with the latter. This sequence of an anabolic agent followed by an antiresorptive should especially be considered in the high-risk patient with imminent fracture risk to rapidly reduce the risk of subsequent fractures. The data surrounding optimum timing of initiation of bisphosphonate therapy following denosumab discontinuation is still unclear. Though data suggests that combining a bisphosphonate with teriparatide does not provide substantial BMD gains compared to monotherapy, the concomitant administration of denosumab with teriparatide has been shown to significantly increase areal BMD as well as to increase volumetric BMD and estimated bone strength. This narrative review explores the available evidence regarding the various sequential and combination therapy approaches and the potential role they could play in better managing osteoporosis.