FRI0499 EFFICACY OF POSTMENOPAUSAL OSTEOPOROSIS TREATMENT BY COMBINATION OF DENOSUMAB WITH PLAIN VITAMIN D OR WITH ANALOG OF VITAMIN D ALFACALCIDOL
Authors: Katarina Pasalic, Snezana Novkovic, Katarina Gosic, Nemanja Damjanov
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> The superiority of the treatment of osteoporosis (OP), using the combination of alendronate (ALN) and alfacalcidol (1αD3) to ALN treatment with cholecalciferol (D3) in both genders, has been demonstrated<sup>1</sup>. <h3>Objectives</h3> To compare the efficacy of two-year OP treatment with denosumab (DMAb) with D3 to the treatment of DMAb with 1αD3. <h3>Methods</h3> Retrospective study included 58 postmenopausal OP patients treated at the Institute of Rheumatology in Belgrade. Average age was 74.5 ± 16.22 years, bone density (BMD) on the lumbar spine (L1L4) was 1.102 ± 0.0878g/cm<sup>2</sup>, total hip (TH) 0.728 ± 0.0324g/cm<sup>2</sup>, femoral neck (FN) was 0,600 ± 0.1281g/cm<sup>2</sup>, and the bone quality expressed as trabecular bone score (TBS) was 1.222 ± 0.3457, at study inclusion. BMD and TBS were measured using Hologic Prodigy DXA device. All women had primary OP, and 50% had fracture in the adult age. Average serum level 25 (OH) D3 was 29.8 ± 6.67ng/mL. Out of all, 68.4% patients had previous OP treatment, during 4.2 ± 3.45 years, 55.2% had used oral bisphosphonates (BF), 8.62% parenteral BF, 3.44% strontium ranelate, while one patient (1.72%) received a full course of teriparatide. Patients were asigned by the doctor’s decision to be treated either by combination of DMAb 60mg s.c. every 6 months and D3 800-1000 IU daily (N = 29) or DMAb and 1αD3 1μg daily (N = 29). Safety was monitored clinically and laboratory at six-month intervals - serum calcium (Ca), ionised Ca, phosphorus, 24 hours of calciuria, incidence of falls and fractures. Serum 25 (OH) D3 and parathormone (PTH) were observed once a year, as well as BMD and TBS. Analytical statistical analysis was done by student t - test and Fisher ‘s test. <h3>Results</h3> The patients were mutualy comparable in term of age, previous fractures, BMD and TBS, laboratory findings, previous OP treatment. After 2 years of study treatment, there was no significant difference in the increase in BMD on the L1L4 between DMAb plus D3 and DMAb plus 1αD3 group (6.4% vs. 6.5%), as well as on the TH (3.3% vs 3.4%). Statistically significantly higher BMD on FN (2.0% vs 5.9%, p&lt;0.001), as well as TBS increase (2% versus 6.7%, p &lt; 0, 05) in DMAb plus 1αD3 group was found. Serum calcitriol was higher (30.54 vs 35.1 ng/mL), while PTH was statistically significant in DMAb plus 1αD3 group (48.6 vs 31.2 pg/mL, p &lt;0.001) at the ed of study. The incidence of hypocalcaemia was 2.3% in the DMAb plus D3 group, and 1.0% in the DMAb plus the 1αD3 group, hyperchalcemia was not found in any. The clinical fractures incidence after 2 years of follow-up was 6.9% in DMAb with D3 and 3.44% in the DMAb plus 1αD3 group, which was not statistically significant, as well as occurence of falls, recorded more frequently in DMAb plus D3 group (31% vs. 13.8%). <h3>Conclusion</h3> DMAb in combination with 1αD3 is more effective and equally safe OP treatment compared to DMAb with D3, in term of increasing FN BMD and improvement of bone micro-architecture. <h3>References</h3> [1] Ringe JD, Farahmand P, Schacht E, Rozehnal A. Superiority of a combined treatment of Alendronate and Alfacalcidol compared to the combination of Alendronate and plain vitamin D or Alfacalcidol alone in established postmenopausal or male osteoporosis (AAC-Trial). Rheumatol Int.2007;27(5):425-34 <h3>Disclosure of Interests</h3> Katarina Pasalic: None declared, Snezana Novkovic: None declared, Katarina Gosic: None declared, Nemanja Damjanov Grant/research support from: AbbVie, Pfizer and Roche, Consultant for: Abbvie, Gedeon Richter, Merck, Novartis, Pfizer and Roche., Speakers bureau: Abbvie, Gedeon Richter, Merck, Novartis, Pfizer and Roche.