2003: Effects of Abaloparatide on Cortical and Trabecular Compartments by 3D-DXA in Men with Osteoporosis

Ruban Dhaliwal¹, John Boxberger², Yamei Wang², Bruce Mitlak², Ludovic Humbert³ and Neil Binkley⁴, ¹Massachusetts General Hospital, Boston, MA, ²Radius Health, Inc., Boston, MA, ³3D-Shaper Medical, Barcelona, Spain, ⁴University of Wisconsin Osteoporosis Clinical Research Program, Madison, WI

Background/Purpose: Abaloparatide (ABL) increases BMD in men with osteoporosis. In the Abaloparatide for the Treatment of Men with Osteoporosis (ATOM) trial, DXA-measured BMD change with ABL 80 μg/day was greater than placebo (PBO) at the lumbar spine, total hip, and femoral neck. The purpose of this study was to evaluate the effects of ABL on cortical and trabecular compartments of the proximal femur in men with osteoporosis using 3D-DXA modeling.

Methods: Blinded hip DXA images from all randomized men in the ATOM trial (n=149 ABL; n=79 PBO) were retrospectively analyzed by 3D-DXA (3D-Shaper software v2.12.0, 3D-Shaper Medical) to evaluate changes from baseline at months 6 and 12 at the total hip. The ATOM trial included men with T-scores ≤−2.5 at the lumbar spine or hip. Men with T-scores ≤−1.5 with a history of radiologic vertebral fracture or low trauma nonvertebral fracture in the past 5 years or ≤−2.0 if >65 years of age were also eligible. Comparisons from baseline were made using paired t tests. Between-group comparisons were made for percent change from baseline data based on a mixed-effect repeated-measure model with treatment, visit, treatment-by-visit interaction and DXA scanner as fixed effects. Other covariates include BMI, age, and value at baseline.

Results: At 12 months, significant within group increases from baseline (P< 0.0001) in integral volumetric BMD (vBMD) (3.7%), trabecular vBMD (7.0%), cortical thickness (1.1%), and cortical surface BMD (sBMD; 1.7%) were observed with ABL. Mean percent change from baseline was greater for ABL compared to PBO (P< 0.01) for all 4 variables (integral vBMD, trabecular vBMD, cortical thickness, cortical sBMD) at 12 months (Figure).Greater increases (P< 0.0001) were also observed at 6 months between ABL and placebo for integral vBMD (2.5% vs 0.04%) and trabecular vBMD (5.7% vs −0.2%).

Conclusion: In men with osteoporosis in ATOM, 6 months of ABL improved trabecular 3D-DXA parameters at the total hip; 12 months of treatment improved cortical and trabecular 3D-DXA parameters at the total hip. These results are broadly consistent with those in postmenopausal women in the ACTIVE study.




R. Dhaliwal: Alexion, 1, 5, Amgen, 1, Ascendis, 1, Radius Health, Inc, 1, 5, Shire, 5, Takeda, 5, Ultragenyx, 1; J. Boxberger: Radius Health, Inc, 3; Y. Wang: Radius Health, Inc, 3; B. Mitlak: Radius Health, Inc, 3; L. Humbert: 3D-Shaper Medical, 3, 11; N. Binkley: Amgen, 2, 5, Radius Health, Inc, 2, 5.