Conditions: Low Bone Mineral Density Postmenopausal Osteoporosis
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 419
Healthy volunteers: no

Brief summary:
The primary objective was to determine the effect of treatment with romosozumab versus placebo at month 12 on the percent change from baseline in bone mineral density (BMD) at the lumbar spine in postmenopausal women with low bone density.

Detailed description:
This study included a 24-month treatment phase followed by rerandomization to a 12-month extension phase with denosumab or placebo, followed by a 12-month retreatment phase with romosozumab, followed by a 24-month follow-on phase with zoledronic acid or no intervention.

* 24-month Romosozumab Treatment Phase (months 1 to 24): Participants were randomized in a 1:1:1:1:1:1:1:1 ratio to receive 1 of 5 double-blind dosing regimens of romosozumab or placebo or open-label alendronate (ALN) or open-label teriparatide (TPTD) for the first 12 months of the study. At month 12, participants in the romosozumab and placebo groups continued their assigned treatment for an additional 12 months, participants in the TPTD group ended study participation, and participants in the ALN group transitioned to receive romosozumab 140 mg subcutaneously (SC) every month (QM) for an additional 12 months (months 12 to 24).
* 12-month Denosumab Extension Phase (months 24 to 36): At the end of the 24-month romosozumab treatment phase, eligible participants were randomized 1:1 within their original treatment group to receive either denosumab or placebo every 6 months (Q6M) for 12 months.
* 12-month Romosozumab Retreatment Phase (months 36 to 48): From months 36 to 48, participants initially randomized to romosozumab or placebo received romosozumab 210 mg SC QM. Participants who initially received ALN ended their participation at month 36 and were not retreated with romosozumab.
* 24-month Follow-on Phase (months 48 to 72): At month 48, participants received 1 dose of zoledronic acid 5 mg intravenously or no intervention for an additional 24 months.

Arms:
arm 1: Participants received placebo matching to romosozumab once a month (QM) or once every 3 months (Q3M) administered subcutaneously (SC) for up to 24 months.

Participants were then rerandomized to receive denosumab 60 mg or placebo to denosumab subcutaneously every 6 months from months 24 to 36. From months 36 to 48 participants received romosozumab 210 mg SC QM. At month 48 eligible participants received a single dose of open-label zoledronic acid 5 mg intravenously, or no intervention. arm 2: Participants received open-label alendronate (ALN) 70 mg orally (PO) every week (QW) for 12 months. At month 12 participants transitioned to receive romosozumab 140 mg subcutaneously every month for an additional 12 months (months 12 to 24).

Participants were then rerandomized to receive denosumab 60 mg or placebo to denosumab subcutaneously every 6 months from months 24 to 36. At month 36 participants ended study participation. arm 3: Participants received open-label teriparatide 20 μg subcutaneously every day (QD) for 12 months. At month 12 participants ended study participation. arm 4: Participants received double-blind romosozumab 70 mg subcutaneously every month for 24 months.

Participants were then rerandomized to receive denosumab 60 mg or placebo to denosumab subcutaneously every 6 months from months 24 to 36. From months 36 to 48 participants received romosozumab 210 mg SC QM. At month 48 eligible participants received a single dose of open-label zoledronic acid 5 mg intravenously, or no intervention. arm 5: Participants received double-blind romosozumab 140 mg subcutaneously once every 3 months for 24 months.

Participants were then rerandomized to receive denosumab 60 mg or placebo to denosumab subcutaneously every 6 months from months 24 to 36. From months 36 to 48 participants received romosozumab 210 mg SC QM. At month 48 eligible participants received a single dose of open-label zoledronic acid 5 mg intravenously, or no intervention. arm 6: Participants received double-blind romosozumab 140 mg QM subcutaneously for 24 months.

Participants were then rerandomized to receive denosumab 60 mg or placebo to denosumab subcutaneously every 6 months from months 24 to 36. From months 36 to 48 participants received romosozumab 210 mg SC QM. At month 48 eligible participants received a single dose of open-label zoledronic acid 5 mg intravenously, or no intervention. arm 7: Participants received double-blind romosozumab 210 mg Q3M subcutaneously for 24 months.

Participants were then rerandomized to receive denosumab 60 mg or placebo to denosumab subcutaneously every 6 months from months 24 to 36. From months 36 to 48 participants received romosozumab 210 mg SC QM. At month 48 eligible participants received a single dose of open-label zoledronic acid 5 mg intravenously, or no intervention. arm 8: Participants received double-blind romosozumab 210 mg QM subcutaneously for 24 months.

Participants were then rerandomized to receive denosumab 60 mg or placebo to denosumab subcutaneously every 6 months from months 24 to 36. From months 36 to 48 participants received romosozumab 210 mg SC QM. At month 48 eligible participants received a single dose of open-label zoledronic acid 5 mg intravenously, or no intervention.

Interventions: intervention 1: Placebo to Romosozumab intervention 2: Alendronate intervention 3: Teriparatide intervention 4: Romosozumab intervention 5: Denosumab intervention 6: Placebo to Denosumab intervention 7: Zoledronic acid
Intervention descriptions: intervention 1: Administered by subcutaneous injection QM or Q3M. intervention 2: Administered orally once a week intervention 3: Teriparatide 20 μg administered by subcutaneous injection once a day intervention 4: Administered by subcutaneous injection intervention 5: Denosumab 60 mg administered by subcutaneous injection Q6M intervention 6: Administered by subcutaneous injection Q6M intervention 7: Zoledronic acid 5 mg administered intravenously

Protocol document: