PTH and Onset: In a cross‐sectional study that enrolled 51 patients with childhood and adult‐onset HPP, 2 of 4 patients who were treated with teriparatide (parathyroid hormone 1‐34) showed clinical and radiological improvement.(61) In a phase IIA open‐label study targeting 8 adult patients with HPP, monoclonal antisclerostin antibody (BPS804) treatment resulted in increases in bone formation markers and bone mineral density.(62) However, these anabolic agents have not been approved for HPP and an effective medical therapy for adult‐onset HPP patients is needed.