The Effect of 3 or 6 Years of Denosumab Exposure in Women With Postmenopausal Osteoporosis: Results From the FREEDOM Extension.

Context:The FREEDOM extension is evaluating the long-term efficacy and safety of denosumab for up to 10 years.Objective:Report results from the first 3 years of the extension, representing up to 6 years of denosumab exposure.Design, Setting, and Participants: Multicenter, international, open-label study of 4550 women.Intervention:Women from the FREEDOM denosumab group received 3 more years of denosumab for a total of 6 years (long-term) and women from the FREEDOM placebo group received 3 years of denosumab (cross-over).Main Outcome Measures:Bone turnover markers (BTMs), bone mineral density (BMD), fracture, and safety.Results:Reductions in BTMs were maintained (long-term) or achieved rapidly (cross-over) following denosumab administration. In the long-term group, BMD further increased for cumulative 6-year gains of 15.2% (lumbar spine) and 7.5% (total hip). During the first 3 years of denosumab treatment, the cross-over group had significant gains in lumbar spine (9.4%) and total hip (4.8%) BMD, similar to the long-term group during the 3-year FREEDOM trial. In the long-term group, fracture incidences remained low and below rates projected for a "virtual placebo" cohort. In the cross-over group, 3-year incidences of new vertebral and nonvertebral fractures were similar to those of the FREEDOM denosumab group. Incidence rates of adverse events did not increase over time. Six participants had events of ONJ confirmed by adjudication. One participant had a fracture adjudicated as consistent with atypical femoral fracture.Conclusion:Denosumab treatment for 6 years remained well tolerated, maintained reduced bone turnover, and continued to increase BMD. Fracture incidence remained low.