Bone Building

          Bone formation and bone resorption are in constant equilibrium until either a disease presents itself or, in women, menopause occurs.  When the equilibrium is disrupted the bone resorption (bone loss) side accelerates causing more bone to disappear and because bone formation continues at the same, then the net effect is more bone loss because bone formation can not keep up with the increased bone loss.

          Most therapeutics slow down bone loss to make it equal to bone formation. However, if the bone has endured too much mineral loss then the structure of the bone is weak. No amount of antiresorptive therapy can return osteoporotic bone to normal. Thus it is important to include anabolic therapies.

          Prior to 2019 there was only one approved anabolic therapeutic (PTH). Recently antisclerostin MAb therapy has been approved completing the validation of sclerostin mechanism as an important target for the treatment of osteoporotic bone.

          In contrast to PTH, antisclerostin therapy offers the advantage of uncoupling bone formation from bone resorption leading to a larger anabolic window in primates.