Abaloparatide-SC improves trabecular microarchitecture as assessed by trabecular bone score (TBS): a 24-week randomized clinical trial

Osteoporos Int. 2018 Feb;29(2):323-328. doi: 10.1007/s00198-017-4304-9. Epub 2017 Nov 22.


In a phase 2 trial of 222 postmenopausal women with osteoporosis aged 55 to 85 years randomized to one of three different doses of abaloparatide-SC, subcutaneous teriparatide, or placebo for 24 weeks, abaloparatide-SC resulted in improvements in skeletal microarchitecture as measured by the trabecular bone score.

Introduction: Subcutaneous abaloparatide (abaloparatide-SC) increases total hip and lumbar spine bone mineral density and reduces vertebral and non-vertebral fractures. In this study, we analyzed the extent to which abaloparatide-SC improves skeletal microarchitecture, assessed indirectly by trabecular bone score (TBS).

Methods: This is a post hoc analysis of a phase 2 trial of 222 postmenopausal women with osteoporosis aged 55 to 85 years randomized to abaloparatide-SC (20, 40, or 80 μg), subcutaneous teriparatide (20 μg), or placebo for 24 weeks. TBS was measured from lumbar spine dual X-ray absorptiometry (DXA) images in 138 women for whom the DXA device was TBS software compatible. Assessments were made at baseline, 12 and 24 weeks. Between-group differences were assessed by generalized estimating equations adjusted for relevant baseline characteristics, and a pre-determined least significant change analysis was performed.

Results: After 24 weeks, TBS increased significantly by 2.27, 3.14, and 4.21% versus baseline in participants on 20, 40, and 80 μg abaloparatide-SC daily, respectively, and by 2.21% in those on teriparatide (p < 0.05 for each). The TBS in the placebo group declined by 1.08%. The TBS increase in each treatment group was significantly higher than placebo at 24 weeks (p < 0.0001 for each) after adjustment for age, BMI, and baseline TBS. A dose-response was observed at 24 weeks across the three doses of abaloparatide-SC and placebo (p = 0.02). The increase in TBS in the abaloparatide-SC 80 μg group was significantly greater than TPTD (p < 0.03).

Conclusions: These results are consistent with an effect of abaloparatide-SC to improve lumbar spine skeletal microarchitecture, as assessed by TBS.

Keywords: Anabolics; Bone microarchitecture; Clinical trials; Osteoporosis.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Aged
  • Aged, 80 and over
  • Bone Density / drug effects*
  • Bone Density Conservation Agents / administration & dosage*
  • Bone Density Conservation Agents / pharmacology
  • Bone Density Conservation Agents / therapeutic use
  • Cancellous Bone / drug effects
  • Cancellous Bone / physiopathology
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Female
  • Humans
  • Injections, Subcutaneous
  • Lumbar Vertebrae / physiopathology
  • Middle Aged
  • Osteoporosis, Postmenopausal / drug therapy*
  • Osteoporosis, Postmenopausal / physiopathology
  • Osteoporotic Fractures / prevention & control
  • Parathyroid Hormone-Related Protein / administration & dosage*
  • Parathyroid Hormone-Related Protein / pharmacology
  • Parathyroid Hormone-Related Protein / therapeutic use
  • Teriparatide / therapeutic use


  • Bone Density Conservation Agents
  • Parathyroid Hormone-Related Protein
  • Teriparatide
  • abaloparatide