Effects of four-year cyclic versus two-year daily teriparatide treatment on volumetric bone density and bone strength in postmenopausal women with osteoporosis

• Published in: Bone (New York, N.Y.) N.Y.), 2023-02, Vol.167, p.116618-116618, Article 116618
• Main Authors: Ganapathy, Aravinda, Nieves, Jeri W., Keaveny, Tony M., Cosman, Felicia
• Format: Article
• Language: English
• Subjects: Alendronate - therapeutic use; Bone Density; Bone Density Conservation Agents - administration & dosage; Bone Density Conservation Agents - therapeutic use; Bone strength; Female; Humans; Osteoporosis - drug therapy; Osteoporosis, Postmenopausal - drug therapy; Postmenopause; QCT; Teriparatide; Teriparatide - administration & dosage; Teriparatide - therapeutic use; Volumetric bone mineral density
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2022.116618

To evaluate the effects of cyclic vs daily teriparatide treatment (TPTD) on volumetric bone mineral density (vBMD) and bone strength at the hip and spine in women who were previously untreated. A total of 86 women were randomized to a 24-month open label treatment of either daily TPTD (20 μg daily) or cyclic TPTD (20 μg daily for 3 months followed by 3 months off). During a 2-year extension, women in the daily TPTD group were switched to alendronate (ALN) and those in the cyclic TPTD group continued on cyclic TPTD (without any ALN). QCT images were acquired at baseline, 2-years (n = 54) and 4-years (n = 35) and analyzed for volumetric integral, cortical and trabecular bone mineral density (vBMD) and bone strength (by finite element analysis) at the hip and spine. The primary analysis presented here compared the responses across equal total TPTD doses (2 years daily vs 4 years cyclic). In the spine, integral vBMD and strength increased substantially after 2 years daily and 4 years cyclic TPTD, with no significant differences (vBMD +12 % vs +11 %, respectively, p = 0.70; spine strength +21 % vs +16 %, respectively, p = 0.35). At the hip, the gains were smaller, but again no significant differences were detected between the groups for the increases in either vBMD (+2 % in both groups, p = 0.97) or hip strength (3 % vs 3 %, p = 0.91). In the spine, the vBMD increment was about twice as large in the trabecular vs peripheral compartment; in the hip, significant vBMD gain was seen only in the trabecular compartment. The gains in volumetric BMD and bone strength for an equivalent dose of TPTD did not depend on whether it was administered every day over two years or cyclically over four years. •Volumetric BMD and strength improved in both the spine and hip in both daily and cyclic groups.•TPTD given 2 years daily or 4 years cyclically increased spine vBMD 12% and 11%, and strength increased 21% and 16%, respectively.•Hip vBMD increased 2% and strength increased 3% whether TPTD was given over 2 years daily or 4 years cyclically.•Most of the gain in vBMD at both spine and hip sites was in trabecular bone, with smaller effects on cortical bone.•Giving TPTD cyclically provides no benefit to vBMD or strength at the spine or hip compared to giving TPTD daily.