• The primary aim of this study is to assess whether an increase in bone mineral density (BMD) will result from the use of rhPTH.
  

• A secondary aim is to determine if PTH therapy will decrease fragility fractures in individuals affected with OI.
  

The purpose of this study is to determine the effectiveness of teriparatide (FORTEO), which is human parathyroid hormone 1-34, for increasing bone mass and improving bone structure in adults affected with Osteogenesis Imperfecta (OI). Osteogenesis imperfecta is an inherited disorder of type I collagen, the major component of bones, characterized by multiple fractures and fragile bones. OI affects approximately 1 to 2 out of every 10,000 individuals of all racial and ethnic origins. There is no cure for osteogenesis imperfecta and there is no established medical therapy for adults with the disorder. Virtually all of the studies reviewing potential treatments for OI have evaluated the effects of medications only on children with OI. Early studies included the use of anabolic steroids, sodium fluoride and testosterone, Vitamins C and D, and calcitonin 1, 4 with minimal or no improvement in bone formation. There is no data concerning the usefulness of parathyroid hormone therapy in OI. Daily low-dose administration of parathyroid hormone (PTH) produces a bone building effect on bone. An effective bone building therapy available for the treatment of adult patients with OI would be an extremely attractive and valuable asset not only to the affected patients but also to the medical community at large.

The working hypothesis is that individuals affected with OI who are treated with FORTEO will experience increased spine and hip bone mineral density and an increase in bone width and thickness. Although FORTEO is not expected to change the defect in the collagen produced, it is expected to increase the quantity of bone formed and improve bone thickness. Therefore, the researchers hypothesize that overall bone strength will be enhanced in OI and fracture incidence will be reduced. Patients with OI will be enrolled in this study for about 18 months. Half the patients will receive PTH (FORTEO) and the other half placebo (no active drug). Blood, urine, and bone density tests will be done during the study for safety monitoring and to see if the PTH is working. Participants will be recruited through the Bone and Mineral Disease clinics, Pediatrics Clinics, Orthopedic clinics, from families of OI patients, the Osteogenesis Imperfecta Foundation, and the general public. The OI Foundation is very enthusiastic about the study and has agreed to alert their membership concerning it. The study will be conducted at each site’s General Clinical Research Center.