Summary: In early postmenopausal women aged 50 to 60 years with bone mineral density T scores below 0 and above -2.5, zoledronate 5 mg IV at baseline and again at 5 years reduced 10-year morphometric vertebral fractures versus placebo, 6.3% versus 11.1% (relative risk 0.56, 95% CI 0.34-0.92; P=0.04), with parallel reductions in fragility, any, and major osteoporotic fractures.
PICO Summary
| Element | Detail |
|---|---|
| Population | 1054 early postmenopausal women aged 50-60 years with bone mineral density T scores below 0 and above -2.5 at the lumbar spine, femoral neck, or hip; 10-year, double-blind, randomized, placebo-controlled trial. |
| Intervention | Zoledronate 5 mg IV at baseline and again at 5 years (n=351). |
| Comparison | Placebo at baseline and at 5 years (n=353). |
| Outcome | New morphometric vertebral fracture occurred in 6.3% (22/351) versus 11.1% (39/353); relative risk 0.56 (95% CI 0.34-0.92; P=0.04), absolute reduction 4.8 points, NNT about 21 over 10 years. Fragility fracture RR was 0.72, any fracture RR 0.70, and major osteoporotic fracture RR 0.60. |
Zoledronate for Fracture Prevention
Phase 4 RCT - early postmenopause - 10 years
Two zoledronate 5 mg infusions given five years apart reduced 10-year morphometric vertebral fractures and other fracture outcomes versus placebo in early postmenopausal women.
Expert Commentary
This trial is useful because it asks a practical prevention question in younger postmenopausal women who are often below treatment thresholds yet remain on a long fracture-risk trajectory. Two 5 mg zoledronate infusions given five years apart reduced morphometric vertebral fractures over 10 years from 11.1% to 6.3%, an absolute reduction of 4.8 percentage points and an NNT of about 21. Secondary reductions in fragility, any, and major osteoporotic fractures strengthen the signal. The trade-off is that the primary endpoint was radiographic vertebral fracture rather than symptomatic fracture, and the study population had bone mineral density T scores between 0 and -2.5, so this does not directly answer how to treat women with established osteoporosis or very low short-term risk. The single-dose group also showed broadly similar secondary outcomes, which suggests durable biologic activity but leaves some uncertainty about the minimum effective schedule. Can I use this with my patients? Yes, selectively. For early postmenopausal women with osteopenia, accumulating risk factors, or concern about long untreated intervals, this supports discussing infrequent IV zoledronate as a long-horizon prevention strategy, while balancing renal function, acute-phase reactions, pregnancy considerations, and the fact that fracture benefit accrued across a decade rather than quickly.
References
Bolland MJ, Nisa Z, Mellar A, et al. Fracture prevention with infrequent zoledronate in women 50 to 60 years of age. N Engl J Med. 2025;392(3):239-248. doi:10.1056/NEJMoa2407031. PMID: 39813642.