Sequential Treatment With Romosozumab Followed by Denosumab vs. Zoledronic Acid for Gains in HIP BMD

Osteoporosis is associated with a high risk of fractures, disability, loss of independence, and excess mortality. Zoledronic acid is an established first-line treatment in Sweden, but many patients at high fracture risk remain at substantial residual fracture risk. Short-course treatment with romosozumab followed by denosumab produces large increases in bone mineral density, but has not been directly compared with zoledronic acid. STRONG-HIP is a multicentre, randomized, active-controlled phase 4 trial in 216 postmenopausal women aged 60 years or older with osteoporosis and high fracture risk. Participants are randomized 1:1 to receive romosozumab 210 mg monthly for 3 months followed by denosumab 60 mg every 6 months, or zoledronic acid 5 mg intravenously at baseline and Month 12. The primary objective is to determine whether the romosozumab-denosumab sequence produces a greater percentage increase in total hip bone mineral density from baseline to Month 24 than zoledronic acid. Secondary outcomes include total hip and lumbar spine BMD at earlier time points, vertebral and clinical fractures, bone turnover markers, safety, health-related quality of life, and health-economic outcomes. A mechanistic substudy will assess bone microarchitecture and estimated strength using HR-pQCT. Participants are followed for 24 months in the main study and may enter an optional extension with follow-up to Month 48 to assess the durability of treatment effects.