FRI0472 COMPARISON OF THE THERAPEUTIC EFFICACY OF DAILY VERSUS WEEKLY DOSE OF TERIPARATIDE FOR PREVENTING BONE FRACTURE IN PATIENTS WITH OSTEOPOROSIS – A SINGLE CENTRE, PROSPECTIVE OPEN-LABEL STUDY
Authors: Takafumi Hagiwara, Kazuya Kamada, Noriyuki Namura
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> In Japan, teriparatide (20 μg) and teriparatide acetate (56.5 μg) have been approved for treatment of osteoporosis. Teriparatide is a recombinant human parathyroid hormone (PTH) administered as daily subcutaneous injections, whereas teriparatide acetate is a biologically active fragment containing the N-terminal 34 amino acids of human PTH administered as weekly subcutaneous injections. To the best of our knowledge, a study comparing the therapeutic effects of these two teriparatide preparations does not exist. <h3>Objectives</h3> We aimed to compare the therapeutic effects of the two teriparatide preparations that varied in dose interval. <h3>Methods</h3> We prospectively enrolled 55 osteoporotic patients with vertebral fracture who needed bone-strengthening therapy in a single-centre cohort. The patients randomly selected either daily injection of teriparatide for 2 years or weekly injection of teriparatide acetate for 72 weeks. The primary endpoint was comparison of the new fracture onset ratio at 18 months, based on the approval for use of teriparatide and teriparatide acetate for up to 2 years and 72 weeks, respectively at the time of the trial. However, since May 2017, teriparatide acetate use for osteoporosis treatment has been approved for up to 24 months in Japan. We evaluated their background data (age, sex, bisphosphonate use, basal disease, glucocorticoid use, vertebral and femoral bone marrow density (BMD), number of thoracic and lumbar vertebral fractures, levels of tartrate-resistant acid phosphatase 5b (TRACP-5b), total procollagen type 1 amino-terminal propeptide (total P1NP), 1,25(OH)2-vitamin D3(1,25(OH)2D3), total serum calcium corrected for albumin level (cCa), inorganic phosphorus(IP), homocysteine, whole PTH and estimated glomerular filtration rate, ankle-brachial index(ABI), and brachial-ankle pulse wave velocity (baPWV)). IP levels were observed until month 1, while levels of TRACP-5b, total P1NP, cCa, 1,25(OH)2D3, BMD, number of fractured vertebrae, ABI, and baPWV were observed until month 18. <h3>Results</h3> The background factors were not significantly different between the groups. The onset rates of new vertebral fractures until 18 months were 50% and 52% for teriparatide and teriparatide acetate, respectively. However, we did not observe the onset of new non-vertebral fracture in the two groups for 18 months. Survival rates in new bone fracture onset (teriparatide vs teriparatide acetate) were 71.4% vs. 60.0% at month 6, 57.1% vs. 52.2% at month 12, and 46.4% vs. 52.2% at month 18. The survival curve showed no significant difference in new bone fracture onset between the groups using the log rank test (p=.976) with a hazard ratio (teriparatide vs. teriparatide acetate) of 0.867 (95% confidential interval; 0.291-2.582) (p=.797) (see Fig.1). No significant differences were seen in the continuation rates for 18 months for teriparatide (93.3%) and teriparatide acetate (96.0%) (p=.669). Statistically significant differences in%Δ vertebral BMD at month 6 and baseline (p&lt;.01); TRACP-5b at months 12 and 18 (p&lt;.05); total P1NP at months 1,6,12, and 18 (p&lt;.01); and cCa at month 6(p&lt;.01) were seen between the groups. Moreover, levels of 1,25(OH)2D3 at months 6, 12, and 18 were lower with teriparatide acetate than those of teriparatide (p&lt;.01). <h3>Conclusion</h3> The protective efficacy of the teriparatide preparations to prevent bone fracture showed no difference. In osteoporosis treatment with vertebral fracture, teriparatide preparation daily or weekly may be selected based on the patient's choice. [UMIN000024503] <h3>References</h3> [1] J Clin Endocrinol Metab. 2012Sep;97(9):3097-106. [2] Arthritis Rheum. 2009Nov;60(11):3346-55. <h3>Disclosure of Interests</h3> None declared