Alendronate treatment for fibrous dysplasia, a rare skeletal disorder

Study Type: Therapy
OE Level of Evidence: 2
Journal Level of Evidence: N/A
Synopsis
40 patients (24 adults and 16 children) with fibrous dysplasia (FD) were randomized to either receive alendronate administration in 6-month cycles for 24 months or placebo. The results revealed that in the alendronate group, NTX-telopeptides markers significantly declined at 18 months, however no significant difference in osteocalcin was observed between groups. Furthermore, areal bone Please login to view the rest of this report. Please login to view the rest of this report.
Funding: Non-Industry funded
Sponsor: National Institutes of Health, Telethon Grant No.GGP09227, the Bone Health Program, Division of Orthopaedics and Sports Medicine, Children’s National Health System, Merck
Conflicts: None disclosed
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Why was this study needed now?
Fibrous dysplasia (FD) is a rare skeletal disorder, characterized by abnormal regulation of osteoblast and osteoclast proliferation and differentiation, causing immature fibrous tissue to take the place of normal bone. Deformity and pain may occur, and bone weakness can lead to an increased risk of fracture. With no effective medical treatment currently available, antiresorptive therapy with bisphosphonates has become of recent interest for this patient population. The body of literature available on bisphosphonate therapy in FD patients has been promising, however has yet to conclusively examine efficacy due to the lack of controlled clinical trials.
What was the principal research question?
Is bisphonphonate (alendronate) therapy over 24 months effective in treatment of fibrous dysplasia when compared to placebo for outcomes of bone turnover markers, bone mineral density, pain scores, and function?
Population: 40 patients over the age of 6 years (24 adults/16 children) with polyostotic FD (2 or more skeletal lesions) were enrolled in the study.
Intervention: Alendronate group: Patients were administered alendronate in two 6-month cycles over the course of 24 months. Weight-dependent dosing was used: 40mg daily for patients >50kg, 20mg for 30-50kg, and 10mg for 20-30kg. Each dose was taken in the morning with a glass of water prior to eating. (n=20, 18 completed 24-wk follow-up)
Comparison: Placebo group: Patients received a placebo instead of alendronate. (n=20, 17 completed 24-wk follow-up)
Outcomes: The primary outcome measures were biomarkers levels of bone resorption (urine N-terminal telopeptide (NTX)) and bone formation (serum osteocalcin). Secondary outcome measures included the assessment of bone pain (Wisconsin Brief Pain Questionnaire), areal bone mineral density (BMD) of FD lesions (dual X-ray absorptiometry (DXA)), and functional parameters (9-minute walk test (9MW) and manual muscle testing (MMT)) related to FD.
Methods: RCT: Double-blinded; Placebo-controlled
Time: Assessments were made at baseline and at 6, 12, 18, and 24 months follow-up.
What were the important findings?
What should I remember most?
How will this affect the care of my patients?
The authors responsible for this critical appraisal and ACE Report indicate no potential conflicts of interest relating to the content in the original publication.