Further Nonvertebral Fracture Reduction Beyond 3 Years for Up to 10 Years of Denosumab Treatment.

CONTEXT: Evidence for further nonvertebral fracture (NVF) reductions with long-term antiresorptive therapy in osteoporosis is lacking.

OBJECTIVE

To evaluate NVF risk reduction in subjects receiving ≤10 years of denosumab treatment.

DESIGN

Phase 3, randomized, placebo-controlled, 3-year Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial (NCT00089791) and its open-label 7-year extension (NCT00523341).

SETTING

One hundred seventy-two study centers worldwide.

PATIENTS: Women 60 to 90 years, lumbar spine or total hip bone mineral density T-scores <-2.5 (≥-4.0 at both).

INTERVENTIONS: Subjects randomly assigned 1:1 denosumab 60 mg SC Q6M (long-term) or placebo (crossover) in FREEDOM; eligible subjects could enroll in the extension to receive denosumab 60 mg SC Q6M.

MAIN OUTCOME MEASURES: NVF Exposure-adjusted subject incidence (per 100 subject-years) during denosumab treatment years 1 to 3 and 4 to 7 (all subjects) and years 4 to 10 (long-term only), and rate ratios (RRs) for years 4 to 7 or 4 to 10 vs 1 to 3.

RESULTS

Among 4074 subjects (2343 long-term, 1731 crossover), NVF rates (95% CI) in all subjects were 2.15 (1.90 to 2.43) during years 1 to 3 and 1.53 (1.34 to 1.75) during years 4 to 7 of denosumab treatment [RR (95% CI) = 0.72 (0.61 to 0.86); P < 0.001]; in long-term only were 1.98 (1.67 to 2.34) during years 1 to 3 and 1.44 (1.24 to 1.66) during years 4 to 10 [RR = 0.74 (0.60 to 0.93); P = 0.008]. combined osteonecrosis of the jaw and atypical femoral fracture rate was 0.06.

CONCLUSIONS

Long-term denosumab treatment, >3 and ≤10 years, was associated with further reductions in NVF rates compared with the first 3 years.