Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: OR10-Osteoporosis
Saturday, June 15, 2013: 11:30 AM-1:00 PM
Presentation Start Time: 12:45 PM
Room 121 (Moscone Center)
Michael R McClung*1, E Michael Lewiecki2, Pei-Ran Ho3, Michael Anthony Bolognese4, Beiying Ding3, Michelle Geller3, Cynthia O'Malley3, Rachel B Wagman3 and Paul D Miller5
1Oregon Osteoporosis Center, Portland, OR, 2New Mexico Clinical Research & Osteoporosis Center and University of New Mexico School of Medicine, Albuquerque, NM, 3Amgen Inc., Thousand Oaks, CA, 4Bethesda Health Research Center, Bethesda, MD, 5Colorado Center for Bone Research, Lakewood, CO
Background: Osteoporosis is a chronic disease that requires long-term treatment with pharmacologic therapy to ensure sustained anti-fracture benefit. Denosumab (DMAb) reduced the risk for vertebral, non-vertebral, and hip fractures (1); and treatment for up to 8 years was associated with continued gains in bone mineral density (BMD) and persistent reduction in markers of bone turnover (2). To understand osteoporosis management strategies after long-term DMAb treatment, we report findings after 1 year of observational follow-up from a phase 2 study extension.

Methods: Subjects who completed the phase 2 extension study were eligible to enter an observational phase designed to understand real-world osteoporosis management strategies. During the observational year, participants received osteoporosis management at the discretion of their treating physician and returned to the clinic after 1 year to undergo BMD assessment and complete an osteoporosis management questionnaire. Incidence of serious adverse events and fractures was collected. All analyses were descriptive.

Results: Of 138 eligible subjects, 82 enrolled in the observational phase and completed the final visit. The majority of subjects (65 [79%]) did not receive any osteoporosis prescription medication (excluding calcium and Vitamin D), with “my doctor felt I no longer needed a medication” given as the most common reason (23 [35%]). Osteoporosis medications taken by the remaining 17 subjects (21%) included alendronate (7 [41%]), DMAb (5 [29%]), risedronate (4 [24%]), ibandronate (2 [12%]) and teriparatide (2 [12%]). In subjects treated with DMAb for 8 years during the double-blind and extension studies (n=52), overall BMD at the end of the 1-year observational phase showed a mean decrease of 6.7% at the lumbar spine and 6.6% at the total hip compared to the end of treatment. In the subset of these 52 subjects who took osteoporosis medication during the observation period (n=10), BMD showed a smaller decline (‑3.7% at lumbar spine and ‑4.1% at total hip). No new safety concerns were identified; 8 subjects (9.8%) experienced 17 fractures with all subjects having at least 1 predisposing risk factor for fracture.

Conclusion: Findings from this 1-year observational phase showed that the majority of subjects were not prescribed further treatment for osteoporosis. Consistent with the mechanism of action of DMAb, treatment cessation was associated with a reversibility of the effect. For subjects who transitioned to another osteoporosis therapy, there was evidence of attenuation of bone loss. A limitation of this study is inherent selection bias with retention of a small number of subjects over 9 years. In conclusion, for patients at high risk for fracture, continuing osteoporosis therapy after DMAb discontinuation seems appropriate.

(1) Cummings et al., NEJM, 2009;361:756. (2) McClung et al., Osteoporos Int, 2013; 24:227.

Disclosure: MRM: Consultant, Amgen, Investigator, Amgen, Consultant, Merck & Co., Consultant, Eli Lilly & Company, Consultant, Novartis Pharmaceuticals, Investigator, Merck & Co., Speaker Bureau Member, Merck & Co., Speaker Bureau Member, Warner Chilcott. EML: Principal Investigator, Amgen, Advisory Group Member, Amgen, Speaker Bureau Member, Amgen, Principal Investigator, Eli Lilly & Company, Advisory Group Member, Eli Lilly & Company, Speaker Bureau Member, Eli Lilly & Company, Principal Investigator, Merck & Co., Principal Investigator, GlaxoSmithKline, Speaker Bureau Member, Novartis Pharmaceuticals, Advisory Group Member, Merck & Co., Consultant, GlaxoSmithKline, Speaker Bureau Member, Warner Chilcott. PRH: Employee, Amgen, Employee, Amgen. MAB: Investigator, Amgen, Speaker, Amgen, Speaker, Astra Zeneca, Investigator, Eli Lilly & Company, Speaker, Eli Lilly & Company, Speaker, GlaxoSmithKline, Investigator, Merck & Co., Speaker, Novartis Pharmaceuticals, Investigator, Roche Pharmaceuticals, Investigator, Proctor & Gamble, Investigator, Takeda. BD: Employee, Amgen, Employee, Amgen. MG: Employee, Amgen, Employee, Amgen. CO: Employee, Amgen, Employee, Amgen. RBW: Employee, Amgen, Employee, Amgen. PDM: Principal Investigator, Amgen, Scientific Board Member, Amgen, Consultant, Amgen, Speaker, Amgen, Scientific Board Member, Proctor & Gamble, Principal Investigator, Proctor & Gamble, Consultant, Proctor & Gamble, Speaker, Proctor & Gamble, Scientific Board Member, Roche Pharmaceuticals, Principal Investigator, Roche Pharmaceuticals, Consultant, Roche Pharmaceuticals, Speaker, Roche Pharmaceuticals, Scientific Board Member, Eli Lilly & Company, Principal Investigator, Eli Lilly & Company, Consultant, Eli Lilly & Company, Speaker, Eli Lilly & Company, Scientific Board Member, Merck & Co., Principal Investigator, Merck & Co., Consultant, Merck & Co., Speaker, Merck & Co., Scientific Board Member, Novartis Pharmaceuticals, Principal Investigator, Novartis Pharmaceuticals, Consultant, Novartis Pharmaceuticals, Speaker, Novartis Pharmaceuticals, Scientific Board Member, Sanofi, Principal Investigator, Sanofi, Consultant, Sanofi, Speaker, Sanofi, Speaker, GlaxoSmithKline, Advisory Group Member, GlaxoSmithKline, Consultant, GlaxoSmithKline, Advisory Group Member, Novartis Pharmaceuticals, Advisory Group Member, Amgen, Advisory Group Member, Roche Pharmaceuticals, Advisory Group Member, Eli Lilly & Company, Advisory Group Member, Merck & Co., Advisory Group Member, Proctor & Gamble, Advisory Group Member, Sanofi, Principal Investigator, Takeda.

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: This work was supported by Amgen Inc.
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