Abstract
Bimagrumab (BYM338) is a novel fully human monoclonal antibody that exerts strong promyogenic effects on skeletal muscle by blocking activin type II receptors (ActRII). We investigated whether such blockade of ActRII by bimagrumab manifests any detrimental effect on outcomes of bone healing in a rat fibula osteotomy model. Animals (n = 150) were divided into 11 groups and received weekly treatment with either bimagrumab (10 or 100 mg/kg) or vehicle. Progression and outcomes of bone healing were assessed by lateral radiographs in vivo as well as by peripheral quantitative computed tomography (pQCT), 4-point bending test, and microscopic examination of the excised fibula at Day 29 or later. The radiographic progression of bone healing showed no significant differences between treatment groups in any comparative setting. In 3-month-old animals, pQCT revealed slightly reduced immature callus size and bone mineral content in bimagrumab-treated animals compared with vehicle-treated animals at Day 29 (p < 0.05). There were, however, no differences in mature callus size, bone mineral density, or biomechanical competency. The aforementioned effects on immature callus size were not present when the treatment was initiated 4 weeks post osteotomy or when treating 6-month-old animals. In summary, these findings suggest that there is no major impact of ActRII blockade on overall fracture healing, and delayed treatment initiation can bypass the small and transient effect of the therapy on immature callus formation observed in younger animals. Verification of these findings in humans is the subject of an ongoing clinical trial on elderly hip fracture patients.
Similar content being viewed by others
References
Schuelke M, Wagner KR, Stolz LE, Hübner C, Riebel T, Kömen W, Braun T, Tobin JF, Lee SJ (2004) Myostatin mutation associated with gross muscle hypertrophy in a child. N Engl J Med 350:2682–2688
Tsuchida K (2008) Targeting myostatin for therapies against muscle-wasting disorders. Curr Opin Drug Discov Dev 11:487–494
Smith RC, Lin BK (2013) Myostatin inhibitors as therapies for muscle wasting associated with cancer and other disorders. Curr Opin Support Palliat Care 7:352–360
Meriggioli MN, Roubenoff R (2015) Prospect for pharmacological therapies to treat skeletal muscle dysfunction. Calcif Tissue Int 96:234–242
Lach-Trifilieff E, Minetti GC, Sheppard K, Ibebunjo C, Feige JN, Hartmann S, Brachat S, Rivet H, Koelbing C, Morvan F, Hatakeyama S, Glass DJ (2014) An antibody blocking activin type ii receptors induces strong skeletal muscle hypertrophy and protects from atrophy. Mol Cell Biol 34:606–618
Amato AA, Sivakumar K, Goyal N, David WS, Salajegheh M, Praestgaard J, Lach-Trifilieff E, Trendelenburg AU, Laurent D, Glass DJ, Roubenoff R, Tseng BS, Greenberg SA (2014) Treatment of sporadic inclusion body myositis with bimagrumab. Neurology 83:2239–2246
Shuto T, Sarkar G, Bronk JT, Matsui N, Bolander ME (1997) Osteoblasts express types I and II activin receptors during early intramembranous and endochondral bone formation. J Bone Miner Res 12:403–411
Nagamine T, Imamura T, Ishidou Y, Kato M, Murata F, ten Dijke P, Sakou T (1998) Immunohistochemical detection of activin A, follistatin, and activin receptors during fracture healing in the rat. J Orthop Res 16:314–321
Sakai R, Miwa K, Eto Y (1999) Local administration of activin promotes fracture healing in the rat fibula fracture model. Bone 25:191–196
An YH, Friedman RJ, Draughn RA (1999) Animal models of bone fracture or osteotomy. Animal models in orthopaedic research. CRC Press, Boca Raton, p 197
Huo MH, Troiano NW, Pelker RR, Gundberg CM, Friedlaender GE (1991) The influence of ibuprofen on fracture repair: biomechanical, biochemical, histologic, and histomorphometric parameters in rats. J Orthop Res 9:383–390
Huddleston PM, Steckelberg JM, Hanssen AD, Rouse MS, Bolander ME, Patel R (2000) Ciprofloxacin inhibition of experimental fracture healing. J Bone Joint Surg Am 82:161–173
Varela A, Chouinard L, Trudel Y, Ruh C, Primakova I, Boyd G, Escott KJ, Smith SY (2011) Fibula osteotomy model in the Sprague–Dawley rat: radiology, densitometry, biomechanics and histological characterization (Poster no. SU0047). Poster presented at the American society for bone and mineral research 2011 annual meeting, September 2011, San Diego
Akpan I, Goncalves MD, Dhir R, Yin X, Pistilli EE, Bogdanovich S, Khurana TS, Ucran J, Lachey J, Ahima RS (2009) The effects of a soluble activin type IIB receptor on obesity and insulin sensitivity. Int J Obes (Lond) 33:1265–1273
Guo T, Jou W, Chanturiya T, Portas J, Gavrilova O, McPherron AC (2009) Myostatin inhibition in muscle, but not adipose tissue, decreases fat mass and improves insulin sensitivity. PLoS One 4:e4937
Liu H, Zhang R, Chen D, Oyajobi BO, Zhao M (2012) Functional redundancy of type II BMP receptor and type IIB activin receptor in BMP-2 induced osteoblast differentiation. J Cell Physiol 227:952–963
Endo K, Sairyo K, Komatsubara S, Sasa T, Egawa H, Ogawa T, Yonekura D, Murakami R, Yasui N (2005) Cyclooxygenase-2 inhibitor delays fracture healing in rats. Acta Orthop 76:470–474
Pountos I, Georgouli T, Blokhuis TJ, Pape HC, Giannoudis PV (2008) Pharmacological agents and impairment of fracture healing: what is the evidence? Injury 39:384–394
Histing T, Garcia P, Holstein JH, Klein M, Matthys R, Nuetzi R, Steck R, Laschke MW, Wehner T, Bindl R, Recknagel S, Stuermer EK, Vollmar B, Wildemann B, Lienau J, Willie B, Peters A, Ignatius A, Pohlemann T, Claes L, Menger MD (2011) Small animal bone healing models: standards, tips, and pitfalls results of a consensus meeting. Bone 49:591–599
Acknowledgments
The authors wish to thank Hardik Ashar (Scientific Writer, Novartis Healthcare Pvt. Ltd., India) for providing excellent support during the finalization of the manuscript including compilation of inputs from authors. This study was funded by Novartis Pharma AG, Basel, Switzerland.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of Interest
Drs. László B. Tankó, Jörg Goldhahn and Andrew Pilling are employees of Novartis and may be eligible for Novartis stock and stock options. Aurore Varela, Elisabeth Lesage, and Susan Y. Smith are employees of Charles River, an organization that received support for conducting this study. Simon Chivers was employed with Novartis at the time of the study conduct and declares no conflict of interest related to this publication.
Human and Animal Rights and Informed Consent
All experimental protocols were reviewed and approved by the Novartis Animal Care and Use Committee (NACUC) of Novartis and the Institutional Animal Care and Use Committee (IACUC) of Charles River and were conducted in compliance with all regulatory, NACUC, and IACUC requirements.
Rights and permissions
About this article
Cite this article
Tankó, L.B., Goldhahn, J., Varela, A. et al. Does Activin Receptor Blockade by Bimagrumab (BYM338) Pose Detrimental Effects on Bone Healing in a Rat Fibula Osteotomy Model?. Calcif Tissue Int 99, 310–321 (2016). https://doi.org/10.1007/s00223-016-0148-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00223-016-0148-0