Cyclic Versus Daily Teriparatide on Bone Mass

Osteoporosis is a serious bone disease that has become an important public health problem. It causes significant loss of bone mass and increases the risk of both fracture and architectural problems with the skeleton. Until recently, the treatments available for osteoporosis primarily prevented further deterioration of bone by reducing the rate of remodeling within the skeleton. This can reduce the risk of fracture by approximately 50%. Teriparatide is a new type of drug for people with osteoporosis who are at high risk of fracture. Teriparatide stimulates bone remodeling and can correct the underlying architectural and bone mass abnormalities that are characteristic of osteoporosis. This study will compare continuous versus cyclic treatment with teriparatide combined with alendronate, another drug for osteoporosis, or teriparatide alone in women with osteoporosis. All participants have completed a parent study of two years that included a screening visit with a physical exam, blood draw, x-rays, EKG, and distribution of calcium and vitamin D supplements. Participants will be separated into two groups according to the treatment they have undergone over the year prior to study entry. Participants who have taken alendronate for at least 1 year prior to study entry will be assigned to Protocol 1. Participants who have not previously taken alendronate will be assigned to Protocol 2. Participants in both protocols will be randomly assigned to one of the following three biopsy groups: pre-treatment; early; or late. Participants in the pre-treatment biopsy group will have a bone biopsy before treatment begins. Those participants in the early biopsy group will have a biopsy at Week 7 of treatment, and those in the late group will have a biopsy at Month 7.5 of treatment. Participants will also be randomly assigned to one of three treatment schedules. Participants in Protocol 1 may be assigned to receive alendronate alone for 24 months; teriparatide daily plus alendronate for 24 months; or teriparatide daily on and off for 3 months at a time plus alendronate for 24 months. Participants in Protocol 2 may be assigned to receive only the supplements they were given during the screening visit; teriparatide daily plus alendronate for 24 months; or teriparatide daily on and off for 3 months at a time for 24 months. Participants will attend assessment visits at Weeks 4 and 7 and Months 3, 5, 6, 7.5, 9, 12, 15, 18, 21, and 24. Visits may include bone turnover measurements, bone mass scans, walking tests, questionnaires, CT scans, and blood draws. A recently funded extension study will extend the treatment period from 24 to 48 months for all consenting. If the individual was assigned to teriparatide daily (with or without alendronate), they will be given alendronate for the 24 to 48 month time period. If the individual was assigned to cyclic teriparatide, they will continue cyclic therapy foro the 24-48 month period (with or without alendronate).