Managing Osteoporosis in Patients on Long-Term Bisphosphonate Treatment: Report of a Task Force of the American Society for Bone and Mineral Research.
Level 5 - mechanism / opinion, no new human data
Task force clinical guidance and narrative review of extension trial evidence
PubMed 26350171 · doi:10.1002/jbmr.2708
What was done
An American Society for Bone and Mineral Research (ASBMR) Task Force reviewed long-term bisphosphonate (BP) safety and efficacy from two clinical trials: the Fracture Intervention Trial Long-term Extension (FLEX; 10 years vs. 5 years of alendronate followed by placebo) and the HORIZON extension (6 annual infusions vs. 3 annual infusions of zoledronic acid followed by placebo). The panel formulated clinical guidance regarding treatment duration, risk stratification, and drug holidays.
What was found
In FLEX, 10 years of alendronate resulted in fewer clinical vertebral fractures than switching to placebo at 5 years. In HORIZON extension, 6 years of zoledronic acid reduced morphometric vertebral fractures compared with stopping at 3 years. A low hip T-score (-2 to -2.5 in FLEX; below -2.5 in HORIZON) predicted benefit from extended therapy. Atypical femoral fracture risk increased with duration of therapy, whereas osteonecrosis of the jaw risk did not. The abstract provides no exact numerical event counts, risk estimates, or confidence intervals.
Why it matters
This report establishes a clinical algorithm for long-term bisphosphonates: reassess risk after 3 years (intravenous) or 5 years (oral), continue treatment for up to 6 to 10 years in high-risk patients, and consider a 2- to 3-year drug holiday in low-risk individuals.
Limits
Recommendations rest on data from only two extension trials and demonstrate protection exclusively for vertebral fractures, without clear evidence for non-vertebral or hip fractures. The evidence comes almost entirely from white postmenopausal women, limiting direct generalizability to men, non-white populations, or patients with glucocorticoid-induced osteoporosis. No quantitative data or effect sizes are provided in the abstract.
Cited by
- supports Bisphosphonates are associated with abnormal femoral fractures.