Postmenopausal women with osteoporosis receiving romosozumab vs teriparatide for 12 months were found to have improved outcomes in bone mineral density (BMD) and bone strength, according to study results published in Journal of Bone and Mineral Research.
Researchers of the current study sought to investigate the 12-month effect of romosozumab and teriparatide treatment on the first lumbar vertebra (L1) of untreated postmenopausal women with low BMD.
Data from a substudy of a phase 2, multi-national, randomized, placebo-controlled trial were analyzed (ClinicalTrials.gov Identifier: NCT00896532).
The analysis included 56 women, aged 55 to 85 years, of whom 17 received 210 mg of romosozumab, 19 received 20 mg of teriparatide, and 20 received placebo for 12 months. Lumbar computed tomography (CT) spine scans were performed at enrollment and at 12 months follow-up. Cortical thickness (CtTh), endocortical thickness (EcTh), cortical BMD (CtBMD), cancellous BMD (CnBMD), and cortical mass surface density (CMSD) were measured across the first lumbar vertebral surface in all the participants. The changes in lumbar vertebrae structure were analyzed and visualized using cortical mapping.
The primary outcomes included percentage change at 12 months compared with baseline in CtTh, CtBMD, EcTh, CnBMD, and CMSD in each group.
Results of the study showed that romosozumab improved all parameters significantly compared with placebo at 12 months. Romosozumab resulted in a mean vertebral CtTh increase of 10.3% vs 4.3% for teriparatide, an EcTh increase of 137.6% vs 47.5% for teriparatide, a CtBMD increase of 2.1% vs a -0.1% (decrease) for teriparatide, and a CMSD increase of 12.4% vs 3.8% for teriparatide. Compared with teriparatide, romosozumab treatment achieved statistical significance (P <.05) for all parameters, except CnBMD (18.1% vs 22.2%, respectively). Both romosozumab and teriparatide achieved statistical significance in all parameters compared with placebo, except for CnBMD, which decreased by 4.6% over a period of 12 months (P <.05).
Cortical mapping of lumbar vertebrae structure showed an increase of CtTh, CtBMD, and CMSD predominantly at the vertebral shell in the teriparatide-treated group, while romosozumab resulted in an overall increase, including the fracture-prone areas of the vertebral shell and endplates.
One study limitation was the small sample size across all treatment groups.
Researchers concluded, “Both [romosozumab and teriparatide] were associated with large and significant increases in cortical and cancellous bone at the vertebrae. At 12 months, romosozumab lead to statistically significantly larger gains compared to teriparatide. This study furthermore demonstrates the locations of bone accrual for these  anabolic agents, which are in regions important for vertebral strength, thereby providing further evidence to support their effectiveness in reducing the risk of fracture.”
Disclosure: This study was supported by Amgen. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Poole KES, Treece GM, Pearson RA, et al. Romosozumab enhances vertebral bone structure in women with low bone density. J Bone Miner Res. Published online November 5, 2021. doi:10.1002/jbmr.4465