Endocrine Abstracts

For a period of nearly 2 decades the use of intravenous bisphosphonates was the only recommended medical treatment for children and adults with osteogenesis imperfecta (OI). In adults some small trials using PTH have been performed showing some osteoanabolic effect. During the last 10 years short acting antiresorptive agents like denosumab have been investigated. Due to the severe rebound after cessation of the treatment and fluctuations in calcium levels this strategy is not recommended. All antiresorptive agents increase bone mass by accumulating “old bone” which has a poor quality due to the structural collagen defect in most patients. Osteoanabolic agents like anti sclerostin antibodies or TGF-beta increase activity of osteoblasts and produce new collagen, which needs to be mineralized. Trials are currently on the way but it will remain unclear how long the treatment needs to be given and what happens after stopping the treatment. In adults a trial assessing the effect of PTH and zoledronic acid is currently performed pathing the way to a sequential therapy of osteoanabolic and antiresorptive treatments in the future. However, all these treatments will not correct the structural collagen defect. A first trial with embryonic mesenchymal stem cells has shown that this approach is safe in children with OI. These stem cells will produce normal collagen and might be able to replace the structural impaired bone in the patients. This might be a treatment alternative in the future while a gene therapy, correcting the mutation, is still not on the horizon currently. In addition to these drugs, the care for patients with OI will remain an interdisciplinary challenge which require surgeons, physiotherapist, pain nurses and many other specialists to provide a treatment adapted to the individual patient with this heterogenous disease.