OR01-1 Superior Gains in Bone Mineral Density and Estimated Strength at the Hip for Romosozumab Compared with Teriparatide in Women with Postmenopausal Osteoporosis Transitioning from Bisphosphonate Therapy: Results of the Phase 3 Open-Label Structure Study

Program: Abstracts - Orals, Poster Previews, and Posters
Session: OR01-Osteoporosis: What You Had, What You Lost, and What You Gain
Friday, April 1, 2016: 11:45 AM-1:15 PM
Presentation Start Time: 11:45 AM
Room 157 (BCEC)
B Langdahl*1, C Libanati2, D B Crittenden3, M A Bolognese4, J P Brown5, N S Daizadeh3, E Dokoupilova6, K Engelke7, J S Finkelstein8, H K Genant9, S Goemaere10, L Hyldstrup11, E Jodar-Gimeno12, T M Keaveny13, D L Kendler14, P Lakatos15, J Maddox3, J Malouf16, F Massari17, J F Molina18, M R Ulla19 and A Grauer3
1Aarhus University Hospital, Aarhus, Denmark, 2UCB Pharma, Brussels, Belgium, 3Amgen Inc., Thousand Oaks, CA, 4Bethesda Health Research Center, Bethesda, MD, 5Laval University and CHU de Québec (CHUL) Research Centre, Quebec City, QC, Canada, 6Medical Plus, Uherske Hradiste, Czech Republic, 7BioClinica, Inc., Hamburg, Germany, 8Department of Medicine, Massachusetts General Hospital, Boston, MA, 9Department of Radiology, University of California, San Francisco, CA, 10Ghent University Hospital, Gent, Belgium, 11Hvidovre University Hospital, Hvidovre, Denmark, 12Servicio de Endocrinología, Hospital Universitario Quirón, Madrid, Spain, 13University of California at Berkeley, Berkeley, CA, 14University of British Columbia, Vancouver, BC, Canada, 15Department of Medicine, Semmelweis University, Budapest, Hungary, 16Universitat Autònoma de Barcelona, Barcelona, Spain, 17Instituto de Investigaciones Metabólicas, Buenos Aires, Argentina, 18Reumalab Centro Integral de Reumatologia, Medellin, Colombia, 19Instituto Latinoamericano de Investigaciones Médicas, Cordoba, Argentina
Purpose: STRUCTURE was a phase 3, open-label study evaluating the effect of romosozumab or teriparatide (TPTD) for 12 months in women with postmenopausal osteoporosis (PMO) transitioning from bisphosphonate therapy (NCT01796301).

Methods: This multi-center, active-controlled study enrolled women with PMO who had taken an oral bisphosphonate for ≥ 3 years prior to screening and alendronate (70 mg weekly or equivalent) in the year prior to screening; had a bone mineral density (BMD) T-score ≤ –2.5 at the total hip (TH), lumbar spine (LS), or femoral neck (FN); and had a history of nonvertebral fracture after age 50 or vertebral fracture. Subjects received daily calcium and vitamin D and were randomized to receive subcutaneous romosozumab 210 mg once monthly or TPTD 20 μg once daily. The primary endpoint was percent change from baseline in BMD by DXA at the TH through month 12 (the average at months 6 and 12). Secondary endpoints included percent change from baseline at months 6 and 12 in BMD by DXA at the TH, LS, and FN; hip integral and cortical BMD by quantitative computed tomography (QCT); and estimated hip strength by finite element analysis. Imaging assessments were done blinded to treatment.

Results: A total of 436 women were randomized to receive romosozumab (N = 218) or TPTD (N = 218) with a mean age of 72 years. Baseline mean TH, LS, and FN T-scores were –2.2, –2.9, and –2.5, respectively. Through 12 months, the mean (95% CI) percent change from baseline in TH BMD by DXA was 2.6% (2.2, 3.0) with romosozumab and –0.6% (–1.0, –0.2) with TPTD (p < 0.0001 between groups). TH BMD changes at months 6 and 12 were significantly larger with romosozumab than with TPTD (p < 0.0001): month 6, 2.3% (1.9, 2.7) vs –0.8% (–1.2, –0.4); month 12, 2.9% (2.5, 3.4) vs –0.5% (–0.9, 0), respectively. Romosozumab also resulted in significantly larger BMD gains at the LS at months 6 and 12 vs TPTD (p < 0.0001): month 6, 7.2% (6.6, 7.8) vs 3.5% (2.9, 4.0); month 12, 9.8% (9.0, 10.5) vs 5.4% (4.7, 6.1), respectively. QCT assessments of the hip demonstrated significantly greater gains in integral and cortical BMD with romosozumab vs TPTD at months 6 and 12 (p < 0.0001). Estimated hip strength gains were also significantly larger with romosozumab at both time points (p < 0.0001) and declined from baseline in TPTD-treated subjects at month 6. The subject incidences of treatment emergent adverse events and adverse events of interest were generally balanced between treatment groups.

Conclusions: In subjects transitioning from bisphosphonate therapy, romosozumab was well-tolerated and was associated with significant BMD gains at both the hip and spine compared with TPTD. BMD gains in the cortical compartment contributed to the greater treatment effect of romosozumab at the hip. Estimated hip strength improved with romosozumab over 12 months but decreased early with TPTD. A global phase 3 program evaluating romosozumab for the treatment of PMO is ongoing.

Disclosure: BL: Speaker, Amgen, Eli Lilly, Merck, Investigational drug, Eli Lilly, Orkla, Advisor, Amgen, Eli Lilly, Merck, UCB Pharma. CL: Employee, UCB Pharma, Employee, UCB Pharma, Employee, UCB Pharma. DBC: Employee, Amgen, Employee, Amgen, Employee, Amgen. MAB: Study Investigator, Amgen, Lilly, Pfizer, Sanofi, Speaker Bureau Member, Amgen. JPB: Speaker, Amgen, Eli Lilly, Study Investigator, Amgen, Eli Lilly, Advisory Group Member, Amgen, Eli Lilly, Merck. NSD: Employee, Amgen, Employee, Amgen, Employee, Amgen. ED: Principal Investigator, Amgen. KE: Employee, BioClinica. HKG: Consultant, Amgen, Janssen, Lilly, Merck, Roche, Synarc. SG: Speaker, Amgen, Principal Investigator, Amgen, MSD, Novartis, Principal Investigator, MSD. LH: Teacher, Amgen, Denmark; Eli-Lilly, Denmark. EJ: Study Investigator, Amgen, Lilly, Speaker, Amgen, Lilly, MSD, Ad Hoc Consultant, Amgen, MSD. TMK: Owner, O.N. Diagnostics, Consultant, Agnovos, Amgen, O.N. Diagnostics. DLK: Medical Lecture, Amgen, Eli Lilly, GSK, Principal Investigator, Astalis, AstraZeneca, Contract Research, Amgen, Eli Lilly, Advisory Board, Amgen, Eli Lilly, Pfizer, Safety monitoring board, Merck & Co.. PL: Speaker, Amgen, Lilly, Servier. JM: Employee, Amgen, Employee, Amgen, Employee, Amgen. JM: Speaker, Gruenenthal, Principal Investigator, Amgen, Lilly España. JFM: Investigator, Amgen. AG: Employee, Amgen, Employee, Amgen, Employee, Amgen. Nothing to Disclose: JSF, FM, MRU

*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting/pr-resources-for-endo

Sources of Research Support: This study was sponsored by Amgen Inc. and UCB Pharma.