Odanacatib, a selective cathepsin K inhibitor, decreases bone resorption, 
whereas osteoclast number increases and bone formation is maintained, perhaps 
even increased on some cortical surfaces. In a phase 2 clinical trial, 
post-menopausal women receiving odanacatib presented a sustained reduction of 
bone resorption markers, whereas procollagen type 1 N-terminal propeptide 
returned to normal. In turn areal bone mineral density increased continuously at 
both spine and hip for up to 5 years. Blosozumab and romosozumab are sclerostin 
neutralizing antibodies that exert potent anabolic effects on both trabecular 
and cortical compartments. A phase 2 clinical trial has reported areal bone 
mineral density gains at spine and hip that were greater with romosozumab 
compared with placebo, but also with teriparatide. It also showed that 
antagonizing sclerostin results in a transient stimulation of bone formation but 
progressive inhibition of bone resorption. Other new medical entities that are 
promising for the treatment of osteoporosis include abaloparatide, a parathyroid 
hormone-related analogue with improved bone formation-resorption ratio.