What is the recommended treatment for osteogenesis imperfecta?

Treatment of Osteogenesis Imperfecta

Bisphosphonates (oral or intravenous) are the recommended first-line pharmacological treatment for adults with osteogenesis imperfecta who have high fracture risk, with intravenous formulations preferred due to better adherence and potentially greater BMD improvements. 1

When to Initiate Pharmacological Treatment

Treatment decisions in adults with OI should be based on multiple clinical factors rather than BMD thresholds alone, as conventional BMD measurements may not reliably predict fracture risk in this population due to qualitative bone defects 1:

Key Indicators for Starting Therapy:

• Very low BMD: T-scores ≤ -3.0 at lumbar spine or hip suggest increased fracture risk and warrant treatment 1
• Recent fracture history: Any fracture within the last 2 years (excluding severe trauma) indicates heightened fracture risk requiring pharmacological intervention 1
• Progressive bone loss: Ongoing BMD decline despite correction of secondary causes should prompt treatment consideration 1
• OI severity: Types III and IV generally have higher fracture rates than Type I, though considerable variability exists within each type 1
• Age and menopausal status: Postmenopausal women face particular risk and may benefit more from therapy 1

First-Line Treatment: Bisphosphonates

Intravenous Bisphosphonates (Preferred)

IV bisphosphonates should be considered the most appropriate option when initiating therapy in most adults with OI 1:

• Zoledronic acid 5 mg annually or neridronate 2 mg/kg (max 100 mg) every 3 months have demonstrated efficacy 1
• IV formulations provide better adherence rates and may be more effective at increasing BMD 1
• Zoledronic acid therapy increased lumbar spine BMD by 6.7-9% and total hip BMD by 10.1-11.1% over 3-5 years 1
• Neridronate improved lumbar spine BMD by ~8.5% and total hip BMD by ~4% at 36 months 1

Oral Bisphosphonates (Alternative)

• Alendronate 70 mg weekly or risedronate 35 mg weekly are feasible alternatives based on patient preference 1
• Oral bisphosphonates increased lumbar spine and total hip BMD by 10.5-14.7% over 2 years 1
• Important caveat: Patients with OI frequently have gastroesophageal reflux disease and GI symptoms that may be exacerbated by oral bisphosphonates 1
• Scoliosis and inability to remain upright for 30 minutes may interfere with proper oral bisphosphonate administration 1

Evidence Limitations

While bisphosphonates consistently improve BMD in adults with OI, conclusive data confirming fracture protection are lacking 1. Only IV bisphosphonates (not oral) showed fracture reduction in OI types III and IV compared to historical controls 1. The risks of osteonecrosis of the jaw (ONJ) and atypical femoral fractures (AFF) do not appear higher in OI patients than in those without OI 1

Second-Line Treatment: Teriparatide

Teriparatide may be an attractive treatment alternative for Type I OI adults with high vertebral fracture risk or intolerance to bisphosphonates 1:

• Teriparatide improves BMD and vertebral bone strength parameters specifically in Type I OI 1
• The BMD-increasing effect appears limited to individuals with Type I OI 1
• Treatment duration: 18-24 months followed by an antiresorptive agent, similar to osteoporosis protocols 1
• Adequate data confirming fracture risk reduction are not yet available 1

Alternative Agents with Limited Evidence

Denosumab

• No data currently support denosumab use in OI treatment 1
• May be considered for OI adults with renal impairment, medication intolerance, or contraindications to bisphosphonates 1
• Critical warning: Denosumab must not be stopped without transitioning to another antiresorptive agent to avoid rebound bone loss and increased fracture risk 1

Abaloparatide

• Not specifically studied in OI, but conceptually no reason to consider it less effective than teriparatide 1

Romosozumab

• Role in adult OI has not been systematically studied 1

Supportive Care and Multidisciplinary Management

Beyond pharmacological treatment, comprehensive management includes 2, 3:

• Physiotherapy and rehabilitation: Essential for maximizing mobility and function 4
• Orthopedic surgery: Needed for fracture treatment, deformity correction, and intramedullary rodding 5
• Calcium and vitamin D optimization: Ensure adequate intake alongside any pharmacological regimen 1

Treatment Duration and Monitoring

• Optimal frequency, duration, and usefulness of drug holidays for IV bisphosphonates remain undefined in OI 1
• Reasonable approach: Utilize osteoporosis treatment guidelines and tailor them based on clinical assessments 1
• Reassess fracture risk after 3-5 years of bisphosphonate therapy to determine whether to continue or initiate a drug holiday 1

Emerging Therapies Under Investigation

• Anti-sclerostin agents and transforming growth factor-beta antagonists are currently being studied in clinical trials 1, 2
• Gene therapy and stem cell therapies offer promising prospects for future curative approaches 6