Thromb Haemost 2012; 107(02): 201-214
DOI: 10.1160/TH11-06-0409
Review Article
Schattauer GmbH

A review of the two major regulatory pathways for non-proprietary low-molecular-weight heparins

Frederick A. Ofosu
1   Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
› Author Affiliations
Further Information

Publication History

Received: 15 June 2011

Accepted after major revision: 12 January 2011

Publication Date:
29 November 2017 (online)

Summary

With the expiry or pending expiry of originator low-molecular-weight heparin (LMWH) patents, pharmaceutical companies have invested in developing non-proprietary versions of LMWHs. LMWHs are manufactured by depolymerising highly purified unfractionated heparin. In contrast to traditional synthetic drugs with well-defined chemical structures, LMWHs contain complex oligosaccharide mixtures and the different manufacturing processes for LMWHs add to the heterogeneity in their physicochemical properties such that the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) consider existing originator LMWHs to be distinct medicinal entities that are not clinically interchangeable. The FDA views LMWHs as drugs and has approved two non-proprietary (generic) LMWHs, using the Abbreviated New Drug Application pathway. In contrast, the World Health Organization and the EMA view LMWHs as biological medicines. Therefore, the EMA and also the Scientific and Standardization Subcommittee on Anticoagulation of the International Society on Thrombosis and Haemostasis and the South Asian Society of Atherosclerosis and Thrombosis have all published specific guidelines for assessing non-proprietary (biosimilar) LMWHs. This manuscript reviews why there are two distinct pathways for approving non-proprietary LMWHs. Available literature on non-proprietary LMWHs approved in some jurisdictions is also reviewed in order to assess whether they satisfy the requirements for LMWHs in the three guidance documents. The review also highlights some of the significant difficulties the two pathways pose for manufacturers and an urgent need to develop a consensus governing the manufacture and regulation of non-proprietary LMWHs to make them more widely available.

 
  • References

  • 1 Geerts WH, Bergqvist D, Pineo GF. et al. Prevention of venous thromboembolism: American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest 2008; 133 (Suppl. 06) 381S-453S.
  • 2 Kearon C, Kahn SR, Agnelli G. et al American College of Chest Physicians. Anti-thrombotic therapy for venous thromboembolic disease: American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest 2008; 133 (Suppl. 06) 454S-545S.
  • 3 Antman EM, Hand M, Armstrong PW. et al. 2007 focused update of the ACC/ AHA 2004 guidelines for the management of patients with ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.. Circulation 2008; 117: 296-329.
  • 4 Anderson JL, Adams CD, Antman EM. et al. ACC/AHA 2007 guidelines for the management of patients with unstable angina/non ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2007; 116: e148-304.
  • 5 Linhardt RJ, Loganathan D, al-Hakim A. et al. Oligosaccharide mapping of low molecular weight heparins: structure and activity differences. J Med Chem 1990; 33: 1639-1645.
  • 6 Linhardt RJ, Gunay NS.. Production and chemical processing of low molecular weight heparins. Semin Thromb Hemost 1999; 25 (Suppl. 03) 5-16.
  • 7 Bianchini P, Liverani L, Mascellani G. et al. Heterogeneity of unfractionated heparins studied in connection with species, source, and production processes. Semin Thromb Hemost 1997; 23: 3-10.
  • 8 Fareed J.. Basic and applied pharmacology of low molecular weight heparins. Pharm Ther 1995; (June Suppl) 16-24.
  • 9 Bisio A, Vecchietti D, Citterio L. et al. Structural features of low-molecular-weight heparins affecting their affinity to antithrombin.. Thromb Haemost 2009; 102: 865-873.
  • 10 Guerrini M, Guglieri S, Naggi A. et al. Low molecular weight heparins: structural differentiation by bidimensional nuclear magnetic resonance spectroscopy.. Semin Thromb Hemost 2007; 33: 478-487.
  • 11 Guerrini M, Elli S, Gaudesi D. et al. Effects on molecular conformation and anticoagulant activities of 1, 6-anhydrosugars at the reducing terminal of antithrombin-binding octasaccharides isolated from low-molecular-weight heparin enoxaparin.. J Med Chem 2010; 53: 8030-8040.
  • 12 Gray E, Mulloy B, Barrowcliffe TW.. Heparin and low-molecular-weight heparin. Thromb Haemost 2008; 99: 807-818.
  • 13 Fareed J, Jeske W, Hoppensteadt D. et al. Low-molecular-weight heparins: pharmacologic profile and product differentiation. Am J Cardiol 1998; 82 (5B): 3L-10L.
  • 14 Jackson CM.. Biosimilars: considerations with low molecular weight heparins. Clin Adv Hematol Oncol 2010; 8: 163-167.
  • 15 European Medicines Agency. Guideline on non-clinical and clinical development of similar biological medicinal products containing low-molecular-weight heparins. London: March 19 2009. (doc. no. EMA/CHMP/BMWP/118264/2007). Available at: http://www.ema.europa.eu/pdfs/human/biosimilar/11826407enfin.pdf (Accessed July 2010).
  • 16 Harenberg J, Kakkar A, Bergqvist D. et al Subcommittee on Control of Anti-coagulation of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis. Recommendations on biosimilar low-molecular-weight heparins.. J Thromb Haemost 2009; 7: 1222-1225.
  • 17 Kalodiki E, Leong W. SASAT and Task Force on Generic LMWHs. SASAT (South Asian Society on Atherosclerosis & Thrombosis) proposal for regulatory guidelines for generic low-molecular weight heparins (LMWHs). Clin Appl Thromb Hemost 2009; 15: 8-11.
  • 18 US Food and Drug Administration. Generic enoxaparin questions and answers (updated July 23, 2010). Available at: http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm220037.htm (Accessed August 19, 2010).
  • 19 US Food and Drug Administration. FDA Approved Drug Products, search terms “enoxaparin sodium (preservative free)”. Available at: http://www.accessdata.fda.gov/scripts/cder/drugsatfda/index.cfm?fuseaction=Search.DrugDetails (Accessed October 10, 2011).
  • 20 McLean J.. The thromboplastic action of cephalin. Am J Physiol 1916; 41: 250-257. Available at: http://ajplegacy.physiology.org/content/vol41/issue2/
  • 21 Brinkhous K, Smith H, Warner E. et al. The inhibition of blood clotting: an unidentified substance which acts in conjunction with heparin to prevent the conversion of prothrombin into thrombin. Am J Physiol 1939; 125: 683-87. Available at: http://ajplegacy.physiology.org/content/vol125/issue4/
  • 22 Johnson EA, Kirkwood TB, Stirling Y. et al. Four heparin preparations: anti-Xa potentiating effect of heparin after subcutaneous injection. Thromb Haemost 1976; 35: 586-591.
  • 23 Thomas DP, Merton RE, Lewis WE. et al. Studies in man and experimental animals of a low molecular weight heparin fraction. Thromb Haemost 1981; 45: 214-218.
  • 24 Barrowcliffe TW, Johnson EA, Eggleton CA. et al. Anticoagulant activities of high and low molecular weight heparin fractions. Br J Haematol 1979; 41: 573-583.
  • 25 Kakkar VV, Djazaeri B, Fok J. et al. Low-molecular-weight heparin and prevention of postoperative deep vein thrombosis. Br Med J (Clin Res Ed) 1982; 284: 375-379.
  • 26 Kakkar VV, Kakkar S, Sanderson RM. et al. Efficacy and safety of two regimens of low molecular weight heparin (Fragmin) in preventing postoperative venous thromboembolism. Haemostasis 1986; 16 (Suppl. 02) 19-24.
  • 27 Kakkar VV, Murray WJ.. Efficacy and safety of low-molecular weight heparin (CY216) in preventing postoperative venous thrombo-embolism: a co-operative study. Br J Surg 1985; 72: 786-791.
  • 28 Kakkar VV, Cohen AT, Edmonson RA. et al. Low molecular weight versus standard heparin for prevention of venous thromboembolism after major abdominal surgery. The Thromboprophylaxis Collaborative Group. Lancet 1993; 341: 259-265.
  • 29 Douketis JD, Berger PB, Dunn AS. et al. The perioperative management of anti-thrombotic therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008; 133 (Suppl. 06) 299S-339S.
  • 30 Turpie AG, Levine MN, Hirsh J. et al. A randomized controlled trial of a low-molecular-weight heparin (enoxaparin) to prevent deep-vein thrombosis in patients undergoing elective hip surgery. N Engl J Med 1986; 315: 925-929.
  • 31 Prins MH, Gelsema R, Sing AK. et al. Prophylaxis of deep venous thrombosis with a low-molecular-weight heparin (Kabi 2165/Fragmin) in stroke patients. Haemostasis 1989; 19: 245-250.
  • 32 Ockelford PA, Patterson J, Johns AS.. A double-blind randomized placebo controlled trial of thromboprophylaxis in major elective general surgery using once daily injections of a low molecular weight heparin fragment (Fragmin). Thromb Haemost 1989; 62: 1046-1049.
  • 33 Pezzuoli G, Neri Serneri GG, Settembrini PG. et al. Effectiveness and safety of the low-molecular-weight heparin CY 216 in the prevention of fatal pulmonary embolism and thromboembolic death in general surgery. A multicentre, double-blind, randomized, controlled clinical trial versus placebo (STEP). STEP Study Group. Haemostasis 1990; 20 (Suppl. 01) 193-204.
  • 34 Sandset PM, Dahl T, Stiris M. et al. A double-blind and randomized placebo-controlled trial of low molecular weight heparin once daily to prevent deep-vein thrombosis in acute ischemic stroke. Semin Thromb Hemost 1990; 16 (Suppl): 25-33.
  • 35 Lassen MR, Borris LC, Christiansen HM. et al. Prevention of thromboembolism in 190 hip arthroplasties. Comparison of LMW heparin and placebo. Acta Orthop Scand 1991; 62: 33-38.
  • 36 Tørholm C, Broeng L, Jørgensen PS. et al. Thromboprophylaxis by low-molecular-weight heparin in elective hip surgery. A placebo controlled study. J Bone Joint Surg Br 1991; 73: 434-438.
  • 37 Jørgensen PS, Knudsen JB, Broeng L. et al. The thromboprophylactic effect of a low-molecular-weight heparin (Fragmin) in hip fracture surgery. A placebo-controlled study. Clin Orthop Relat Res 1992; 278: 95-100.
  • 38 Boneu B.. An international multicentre study: Clivarin in the prevention of venous thromboembolism in patients undergoing general surgery. Report of the International Clivarin Assessment Group. Blood Coagul Fibrinolysis 1993; 4 (Suppl. 01) S21-22.
  • 39 Faxon DP, Spiro TE, Minor S. et al. Low molecular weight heparin in prevention of restenosis after angioplasty. Results of Enoxaparin Restenosis (ERA) Trial. Circulation 1994; 90: 908-914.
  • 40 Kalodiki EP, Hoppensteadt DA, Nicolaides AN. et al. Deep venous thrombosis prophylaxis with low molecular weight heparin and elastic compression in patients having total hip replacement. A randomised controlled trial. Int Angiol 1996; 15: 162-168.
  • 41 Planes A, Vochelle N, Darmon JY. et al. Efficacy and safety of postdischarge administration of enoxaparin in the prevention of deep venous thrombosis after total hip replacement. A prospective randomised double-blind placebo-controlled trial. Drugs 1996; 52 (Suppl. 07) 47-54.
  • 42 Planes A, Vochelle N, Darmon JY, Fagola M, Bellaud M, Huet Y.. Risk of deep-venous thrombosis after hospital discharge in patients having undergone total hip replacement: double-blind randomised comparison of enoxaparin versus placebo. Lancet 1996; 348: 224-228.
  • 43 Horbach T, Wolf H, Michaelis HC. et al. A fixed-dose combination of low molecular weight heparin with dihydroergotamine versus adjusted-dose unfractionated heparin in the prevention of deep-vein thrombosis after total hip replacement. Thromb Haemost 1996; 75: 246-250.
  • 44 Lausen I, Jensen R, Jorgensen LN. et al. Incidence and prevention of deep venous thrombosis occurring late after general surgery: randomised controlled study of prolonged thromboprophylaxis. Eur J Surg 1998; 164: 657-663.
  • 45 Planes A, Samama MM, Lensing AW. et al. Prevention of deep vein thrombosis after hip replacement – comparison between two low molecular weight heparins, tinzaparin and enoxaparin. Thromb Haemost 1999; 81: 22-25.
  • 46 Bara L, Planes A, Samama MM.. Occurrence of thrombosis and haemorrhage, relationship with anti-Xa, anti-IIa activities, and D-dimer plasma levels in patients receiving a low molecular weight heparin, enoxaparin or tinzaparin, to prevent deep vein thrombosis after hip surgery. Br J Haematol 1999; 104: 230-240.
  • 47 Mismetti P, Laporte S, Darmon JY, Buchmüller A, Decousus H.. Meta-analysis of low molecular weight heparin in the prevention of venous thromboembolism in general surgery. Br J Surg 2001; 88: 913-930.
  • 48 Ornstein DL, Hong-Dice YG, Papini JR.. Low-molecular-weight heparins for the prevention and treatment of venous thromboembolism. Mil Med 2001; 166: 593-601.
  • 49 Kolb G, Bodamer I, Galster H. et al. Reduction of venous thromboembolism following prolonged prophylaxis with the low molecular weight heparin Certoparin after endoprothetic joint replacement or osteosynthesis of the lower limb in elderly patients.. Thromb Haemost 2003; 90: 1100-1105.
  • 50 Camporese G, Bernardi E, Prandoni P. et al. Low-molecular-weight heparin versus compression stockings for thromboprophylaxis after knee arthroscopy: a randomized trial.. Ann Intern Med 2008; 149: 73-82.
  • 51 Bianchini P, Liverani L, Spelta F. et al. Variability of heparins and heterogeneity of low molecular weight heparins.. Semin Thromb Hemost 2007; 33: 496-502.
  • 52 Fareed J, Hoppensteadt D, Jeske W. et al. Low molecular weight heparins: a developmental perspective. Expert Opin Investig Drugs 1997; 6: 705-733.
  • 53 Jeske W, Fareed J.. In vitro studies on the biochemistry and pharmacology of low molecular weight heparins. Semin Thromb Hemost 1999; 25 (Suppl. 03) 27-33.
  • 54 European Pharmacopoeia 6th Edition. Council of Europe (COE) – European Directorate for the Quality of Medicines (EDQM). Monographs 01/2008:1097 Enoxaparin sodium; 01/2008:1195 Dalteparin sodium; 01/2008:1271 Tinzaparin sodium; 01/2008:1252 Parnaparin sodium; 01/2008:1134 Nadroparin calcium; 01/2008:0828 Low Molecular Mass Heparin. Available at: http://www.edqm.eu/ Accessed October 10, 2011.
  • 55 North American Thrombosis Forum. Thoughts on approval guidelines for generic heparins and low molecular weight heparins. Written communications to the FDA.. Available at: http://natfonline.org/docs/FINAL%20NATF%20Written%20Communication%20to%20FDA.pdf (Accessed June 15, 2010).
  • 56 United States Government. 111th Congress of the United States of America. The Patient Protection and Affordable Care Act. HR 3590. March 2010.. Available at: http://democrats.senate.gov/reform/patient-protection-affordable-care-act-as-passed.pdf (Accessed June 11, 2010).
  • 57 US Food and Drug Administration. Center for Drug Evaluation and Research. Approved Drug Products with Therapeutic Equivalence Evaluations. 30th edition, 2009.. Available at: http://www.fda.gov/ucm/groups/fdagov-public/@fdagov-drugs-gen/documents/document/ucm071436.pdf (Accessed July 30, 2009).
  • 58 Frank RG.. Regulation of follow-on biologics. N Engl J Med 2007; 357: 841-843.
  • 59 Pharmaceutical Research and Manufacturers of America. Pharmaceutical industry profile 2008. Washington, DC: 2008. Available at: http://www.phrma.org/files/attachments/2008%20Profile.pdf (Accessed December 1, 2010).
  • 60 Generics and Biosimilars Initiative. Brand-name versus generic drug costs.. Available at: http://www.gabionline.net/Generics/General/Brand-name-versus-generic-drug-costs (Accessed October 10, 2011).
  • 61 Warkentin TE, Cook RJ, Marder VJ, Greinacher A.. Anti-PF4/heparin antibody formation postorthopedic surgery thromboprophylaxis: the role of non-drug risk factors and evidence for a stoichiometry-based model of immunization.. J Thromb Haemost 2010; 8: 504-512.
  • 62 Ahmad S, Haas S, Hoppensteadt DA. et al. Differential effects of clivarin and heparin in patients undergoing hip and knee surgery for the generation of anti-heparin-platelet factor 4 antibodies.. Thromb Res 2002; 108: 49-55.
  • 63 Gruel Y, Pouplard C, Nguyen P. et al. Biological and clinical features of low-molecular-weight heparin-induced thrombocytopenia.. Br J Haematol 2003; 121: 786-792.
  • 64 Zhang Z, Weïwer M, Li B. et al. Oversulfated chondroitin sulfate: impact of a heparin impurity, associated with adverse clinical events, on low-molecular-weight heparin preparation.. J Med Chem 2008; 51: 5498-5501.
  • 65 US Food and Drug Administration. Establishing active ingredient sameness for generic enoxaparin sodium, a low molecular weight heparin (updated July 23, 2010). Available at: http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm220023.htm (Accessed August 20, 2010).
  • 66 Guerrini M, Bisio A, Torri G.. Combined quantitative (1)H and (13)C nuclear magnetic resonance spectroscopy for characterization of heparin preparations. Semin Thromb Hemost 2001; 27: 473-482.
  • 67 Rudd TR, Skidmore MA, Guimond SE. et al. The potential for circular dichroism as an additional facile and sensitive method of monitoring low-molecular-weight heparins and heparinoids.. Thromb Haemost 2009; 102: 874-878.
  • 68 Zhang Z, Li B, Zhang F. et al. Analysis of pharmaceutical heparins and potential contaminants using (1)H-NMR and PAGE.. J Pharm Sci 2009; 98: 4017-4026.
  • 69 Rudd TR, Gaudesi D, Lima MA. et al. High-sensitivity visualisation of contaminants in heparin samples by spectral filtering of 1H NMR spectra. Analyst 2011; 136: 1390-1398.
  • 70 Rudd TR, Gaudesi D, Skidmore MA. et al. Construction and use of a library of bona fide heparins employing 1H NMR and multivariate analysis. Analyst 2011; 136: 1380-1389.
  • 71 European Medicines Agency. Guideline on similar biological medicinal products containing biotechnology-derived proteins as active substance: non-clinical and clinical issues. London, February 22, 2006 (doc. no. EMA/CHMP/BMWP/42832/2005). Available at: http://www.ema.europa.eu/pdfs/human/biosimilar/4283205en.pdf (Accessed July 2010).
  • 72 Crommelin D, Bermejo T, Bissig M. et al. Biosimilars, generic versions of the first generation of therapeutic proteins: do they exist?. Contrib Nephrol 2005; 149: 287-294.
  • 73 Crommelin D, Bermejo T, Bissig M. et al. Pharmaceutical evaluation of biosimilars: important differences from generic low-molecular-weight pharmaceuticals.. Eur J Hosp Pharm Sci 2005; 11: 11-17.
  • 74 Woodcock J.. May 2, 2007 testimony to United States Senate: assessing the impact of a safe and equitable biosimilar policy in the United States. Available at: http://www.fda.gov/NewsEvents/Testimony/ucm154017.htm Accessed June 2010.
  • 75 Schellekens H.. When biotech proteins go off-patent.. Trends Biotechnol 2004; 22: 406-410.
  • 76 Casadevall N, Nataf J, Viron B. et al. Pure red-cell aplasia and antierythropoietin antibodies in patients treated with recombinant erythropoietin.. N Engl J Med 2002; 346: 469-475.
  • 77 Health Canada. Guidance for sponsors: information and submission requirements for subsequent entry biologics (SEBs). Ottawa: March 5 2010. Available at: http://www.hc-sc.gc.ca/dhp-mps/alt_formats/pdf/brgtherap/applic-demande/guides/seb-pbu/seb-pbu-2010-eng.pdf (Accessed June 10, 2010).
  • 78 World Health Organization. Expert Committee on Biological Standardization. Guidelines on evaluation of similar biotherapeutic products (SBPs). Geneva: October 2009. Available at: http://www.who.int/biologicals/areas/biological_therapeutics/BIOTHERAPEUTICS_FOR_WEB_22APRIL2010.pdf (Accessed August 19, 2010).
  • 79 Generics and Biosimilars Initiative. Global biosimilars guideline development – EGA’s perspective. Posted September 28, 2009. Available at: http://www.gabionline.net/Guidelines/Global-biosimilars-guideline-development-EGA-s-perspective (Accessed July 2010).
  • 80 Australian Government Department of Health and Ageing Therapeutic Goods Administration. European Medicines Agency. Guideline on non-clinical and clinical development of similar biological medicinal products containing low-molecular-weight heparins. London: March 19 2009. (doc. no. EMA/CHMP/BMWP/118264/2007) Available at: www.tga.gov.au/pdf/euguide/bmwp11826407en.pdf (Accessed June 2011).
  • 81 Loganathan D, Wang HM, Mallis LM. et al. Structural variation in the antithrombin III binding site region and its occurrence in heparin from different sources. Biochemistry 1990; 29: 4362-4368.
  • 82 Mulloy B, Gray E, Barrowcliffe TW.. Characterization of unfractionated heparin: comparison of materials from the last 50 years. Thromb Haemost 2000; 84: 1052-1056.
  • 83 Hirsh J, Bauer KA, Donati MB. et al American College of Chest Physicians. Parenteral anticoagulants: American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest 2008; 133 (Suppl. 06) 141S-159S.
  • 84 Bianchini P, Nader HB, Takahashi HK. et al. Fractionation and identification of heparin and other mucopolysaccharides by a new discontinuous electrophoretic method. J Chromatogr 1980; 196: 455-462.
  • 85 Bianchini P, Osima B, Parma B. et al. Fractionation and structural features of two heparin families with high antithrombotic, antilipemic and anticoagulant activities. Arzneimittelforschung 1985; 35: 1215-1219.
  • 86 Rosenberg RD.. Actions and interactions of antithrombin and heparin. N Engl J Med 1975; 292: 146-151.
  • 87 Lindahl U, Hook M.. Glycosaminoglycans and their binding to biological macro-molecules. Annu Rev Biochem 1978; 47: 385-417.
  • 88 Griffith MJ.. Kinetic analysis of the heparin-enhanced antithrombin III/thrombin reaction. Reaction rate enhancement by heparin-thrombin association. J Biol Chem 1979; 254: 12044-12049.
  • 89 Holmer E, Kurachi K, Soderstrom G.. The molecular-weight dependence of the rate-enhancing effect of heparin on the inhibition of thrombin, factor Xa, factor IXa, factor XIa, factor XIIa and kallikrein by antithrombin. Biochem J 1981; 193: 395-400.
  • 90 Wagenvoord R, Al Dieri R, van Dedem G. et al. Linear diffusion of thrombin and factor Xa along the heparin molecule explains the effects of extended heparin chain lengths.. Thromb Res 2008; 122: 237-245.
  • 91 Hedner U.. Development of tinzaparin: a heparinase-digested low-molecular-weight heparin. Semin Thromb Hemost 2000; 26 (Suppl. 01) 23-29.
  • 92 Ernst S, Langer R, Cooney CL. et al. Enzymatic degradation of glycosaminoglycans. Crit Rev Biochem Mol Biol 1995; 30: 387-444.
  • 93 Jeske W, Iqbal O, Gonnela S. et al. Pharmacologic profile of a low-molecular-weight heparin depolymerized by gamma-irradiation. Semin Thromb Hemost 1995; 21: 201-211.
  • 94 Vismara E, Pierini M, Guglieri S. et al. Structural modification induced in heparin by a Fenton-type depolymerization process.. Semin Thromb Hemost 2007; 33: 466-477.
  • 95 Schroeder M, Hogwood J, Gray E. et al. Protamine neutralisation of low molecular weight heparins and their oligosaccharide components.. Anal Bioanal Chem 2011; 399: 763-771.
  • 96 Casu B, Torri G.. Structural characterization of low molecular weight heparins. Semin Thromb Hemost 1999; 25 (Suppl. 03) 17-25.
  • 97 Jeske WP, Neville B, Ma Q. et al. Effect of 1, 6-anhydro bicyclic ring structure on the pharmacokinetic and pharmacodynamic behavior of low molecular weight heparin. Blood (ASH Annual Meeting Abstracts). 2004 104. Abstract 1868. Available at: http://abstracts.hematologylibrary.org/cgi/content/abstract/104/11/1868
  • 98 Bray B, Lane DA, Freyssinet JM. et al. Antithrombin activities of heparin. Effect of saccharide chain length on thrombin inhibition by heparin cofactor II and by antithrombin. Biochem J 1989; 262: 225-232.
  • 99 Alban S.. Molecular weight-dependent influence of heparin on the form of tissue factor pathway inhibitor circulating in plasma.. Semin Thromb Hemost 2001; 27: 503-511.
  • 100 Khorana AA, Sahni A, Altland OD. et al. Heparin inhibition of endothelial cell proliferation and organization is dependent on molecular weight.. Arterioscler Thromb Vasc Biol 2003; 23: 2110-2115.
  • 101 Crowther MA, Berry LR, Monagle PT. et al. Mechanisms responsible for the failure of protamine to inactivate low-molecular-weight heparin.. Br J Haematol 2002; 116: 178-186.
  • 102 Kuziej J, Litinas E, Hoppensteadt A. et al. In vivo neutralization of unfractionated heparin and low-molecular-weight heparin by a novel salicylamide derivative.. Clin Appl Thromb Hemost 2010; 16: 377-386.
  • 103 Dawes J, Bara L, Billaud E. et al. Relationship between biologic activity and concentration of a low-molecular-weight heparin (PK 10169) and unfractionated heparin after intravenous and subcutaneous administration. Haemostasis 1986; 16: 116-122.
  • 104 Ma Q, Tobu M, Schultz C. et al. Molecular weight dependent tissue factor pathway inhibitor release by heparin and heparin oligosaccharides.. Thromb Res 2007; 119: 653-661.
  • 105 Samama MM, Gerotziafas GT. Comparative pharmacokinetics of LMWHs. Semin Thromb Hemost 2000; 26 (Suppl. 01) 31-38.
  • 106 Bégum S, Welzel D, Al Dieri R. et al. Conjectures and refutations on the mode of action of heparins. The limited importance of anti-factor Xa activity as a pharmaceutical mechanism and a yardstick for therapy. Haemostasis 1999; 29: 170-178.
  • 107 Gerotziafas GT, Petropoulou AD, Hatmi M. et al. Inhibition of In Vitro Thrombin Generation: Another Parameter Reinforcing the LMWH Heterogeneity. Blood (ASH Annual Meeting Abstracts). 2005 106. Abstract 912. Available at: http://abstracts.hematologylibrary.org/cgi/content/abstract/106/11/912?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=Gerotziafas&searchid=1&FIRSTINDEX=0&volume=106&issue=11&resourcetype=HWCIT
  • 108 Fareed J, Jeske W, Fareed D. et al. Are all low molecular weight heparins equivalent in the management of venous thromboembolism?. Clin Appl Thromb Hemost 2008; 14: 385-392.
  • 109 Jeske WP, Walenga JM, Hoppensteadt DA. et al. Differentiating low-molecular-weight heparins based on chemical, biological, and pharmacologic properties: implications for the development of generic versions of low-molecular-weight heparins.. Semin Thromb Hemost 2008; 34: 74-85.
  • 110 Fareed J, Hoppensteadt D, Schultz C. et al. Biochemical and pharmacologic heterogeneity in low molecular weight heparins. Impact on the therapeutic profile. Curr Pharm Des 2004; 10: 983-999.
  • 111 Gray E, Rigsby P, Behr-Gross ME.. Collaborative study to establish the low-molecular-mass heparin for assay--European Pharmacopoeia Biological Reference Preparation. Pharmeuropa Bio 2004; 2004: 59-76.
  • 112 Montalescot G, Collet JP, Lison L. et al. Effects of various anticoagulant treatments on von Willebrand factor release in unstable angina.. J Am Coll Cardiol 2000; 36: 110-114.
  • 113 Mousa SA.. Heparin, low molecular weight heparin, and derivatives in thrombosis, angiogenesis, and inflammation: emerging links. Semin Thromb Hemost 2007; 33: 524-533.
  • 114 Harenberg J.. LMWH – new mechanisms of action. Thromb Res 2009; 123 (Suppl. 03) S1-4.
  • 115 Van der Heijden JF, Prins MH, Buller HR. Low-molecular weight heparins: are they interchangeable?. Haemostasis 2000; 30 (Suppl. 02) 148-157.
  • 116 Lopez LM.. Low-molecular weight heparins are essentially the same for treatment and prevention of thromboembolism. Pharmacotherapy 2001; 21: 56S-61S.
  • 117 Prandoni P.. Low molecular weight heparins: are they interchangeable? Yes.. J Thromb Haemost 2003; 1: 10-11.
  • 118 Nenci GG.. Low molecular weight heparins: are they interchangeable? No.. J Thromb Haemost 2003; 1: 12-13.
  • 119 McCart GM, Kayser SR.. Therapeutic equivalency of low-molecular-weight heparins. Ann Pharmacother 2002; 36: 1042-1057.
  • 120 Nightingale SL.. From the Food and Drug Administration. J Am Med Assoc 1993; 270: 1672.
  • 121 Kistler U, Kramers-de Quervain I, Munzinger U. et al. Bleeding complications after systematic switch of routine thromboprophylaxis for major orthopaedic surgery.. Thromb Haemost 2008; 99: 1049-1052.
  • 122 Levine MN, Hirsh J, Gent M. et al. Prevention of deep vein thrombosis after elective hip surgery. A randomized trial comparing low molecular weight heparin with standard unfractionated heparin. Ann Intern Med 1991; 114: 545-551.
  • 123 Ellison J, Thomson AJ, Conkie JA. et al. Thromboprophylaxis following caesarean section--a comparison of the antithrombotic properties of three low molecular weight heparins--dalteparin, enoxaparin and tinzaparin.. Thromb Haemost 2001; 86: 1374-1378.
  • 124 Okmen E, Ozen E, Uyarel H. et al. Effects of enoxaparin and nadroparin on major cardiac events in high-risk unstable angina treated with a glycoprotein IIb/ IIIa inhibitor.. Jpn Heart J 2003; 44: 899-906.
  • 125 Simonneau G, Laporte S, Mismetti P. et al. A randomized study comparing the efficacy and safety of nadroparin 2850 IU (0.3 mL) vs. enoxaparin 4000 IU (40 mg) in the prevention of venous thromboembolism after colorectal surgery for cancer. J Thromb Haemost 2006; 4: 1693-1700.
  • 126 Mahé I, Aghassarian M, Drouet L. et al. Tinzaparin and enoxaparin given at prophylactic dose for eight days in medical elderly patients with impaired renal function: a comparative pharmacokinetic study.. Thromb Haemost 2007; 97: 581-586.
  • 127 Katsouras C, Michalis LK, Papamichael N. et al. Enoxaparin versus tinzaparin in non-ST-segment elevation acute coronary syndromes: results of the enoxaparin versus tinzaparin (EVET) trial at 6 months.. Am Heart J 2005; 150: 385-391.
  • 128 Yoshida BW.. Studies on biosimilar medications. J Vasc Bras 2010; 9: 141-144. Available at: http://www.jvascbr.com.br/10–09–03/jvb_n9v3_pg141–144.pdf (Accessed October 10, 2011).
  • 129 Melo EI, Pereira MS, Cunha RS, Sá MP, Mourão PA.. Heparin quality control in the Brazilian market: implications in the cardiovascular surgery. Rev Bras Cir Cardiovasc 2008; 23: 169-174.
  • 130 Aquino RS, Pereira MS, Vairo BC. et al. Heparins from porcine and bovine intestinal mucosa: are they similar drugs?. Thromb Haemost 2010; 103: 1005-1010.
  • 131 Maddineni J, Walenga JM, Jeske WP. et al. Product individuality of commercially available low-molecular-weight heparins and their generic versions: therapeutic implications.. Clin Appl Thromb Hemost 2006; 12: 267-276.
  • 132 Jeske WP, Walenga JM, Ackerman PD. et al. Assay dependent variations in the anticoagulant and protamine sulfate neutralization profiles of generic copies of enoxaparin. Blood (ASH Annual Meeting Abstracts). 2006 108. Abstract 908. Available at: http://abstracts.hematologylibrary.org/cgi/content/abstract/108/11/908
  • 133 Jeske WP, Brubaker A, Hoppensteadt D. et al. Differences in the oligosaccharide composition of generic versions of enoxaparin and dalteparin. J Thromb Haemost. 2007 5. (Suppl 2): Abstract P-M-670.
  • 134 Adiguzel C, Litinas E, Cunanan J. et al. Differential thrombin generation inhibition by branded and generic low molecular weight heparins (LMWHS) as studied by using fluorescence substrate based kinetic method. Int Angiol 2010; 29 (Suppl. 02) 73.
  • 135 Walenga JM, Adiguzel C, Iqbal O. et al. Fibrin clot formation differs in the presence of branded and generic enoxaparins. Int Angiol 2010; 29 (Suppl. 02) 86.
  • 136 Walenga JM, Hoppensteadt D, Cunanan J. et al. Immunogenicity of low molecular weight heparins and biosimilars. Int Angiol 2010; 29 (Suppl. 02) 85.
  • 137 Goodwin CA, Clutterbuck R, Scully MF. et al. The discrimination of generic forms of LMW heparin using a proteomic cell-based approach. J Thromb Haemost. 2007 5. (Suppl 2): Abstract P-M-514.
  • 138 Jeske WP, Walenga JM, Hoppensteadt D. et al. Pharmacodynamic differentiation of generic low molecular weight heparins. Blood (ASH Annual Meeting Abstracts). 2007 110. Abstract 1871. Available at: http://abstracts.hematologylibrary.org/cgi/content/abstract/110/11/1871
  • 139 Kuczka K, Harder S, Picard-Willems B. et al. Biomarkers and coagulation tests for assessing the biosimilarity of a generic low-molecular-weight heparin: results of a study in healthy subjects with enoxaparin.. J Clin Pharmacol 2008; 48: 1189-1196.
  • 140 Feng L, Shen-Tu J, Liu J. et al. Bioequivalence of generic and branded subcutaneous enoxaparin: a single-dose, randomized-sequence, open-label, two-period crossover study in healthy Chinese male subjects.. Clin Ther 2009; 31: 1559-1567.
  • 141 Turpie AG, Bauer KA, Eriksson BI. et al. Fondaparinux vs. enoxaparin for prevention of venous thromboembolism in major orthopedic surgery: a meta-analysis of 4 randomized double-blind studies. Arch Intern Med 2002; 162: 1833-1840.
  • 142 Eriksson BI, Bauer KA, Lassen MR. et al. Fondaparinux compared with enoxaparin for the prevention of venous thromboembolism after hip-fracture surgery.. N Engl J Med 2001; 345: 1298-1304.
  • 143 Eriksson BI, Dahl OE, Rosencher N. et al. Dabigatran etexilate versus enoxaparin for prevention of venous thromboembolism after total hip replacement: a randomized, double-blind, non-inferiority trial.. Lancet 2007; 370: 949-956.
  • 144 Kakkar AK, Brenner B, Dahl OE. et al RECORD-2 Investigators. Extended duration rivaroxaban versus short-term enoxaparin for the prevention of venous thromboembolism after total hip arthroplasty: a double-blind, randomized controlled trial. Lancet 2008; 372: 31-39.
  • 145 Eriksson BI, Borris L, Friedman RJ. et al RECORD-1 Study Group. Rivaroxaban versus enoxaparin for thromboprophylaxis after hip arthroplasty. N Engl J Med 2008; 358: 2765-2775.
  • 146 Turpie AGG, Lassen MR, Davidson BL. et al. Rivaroxaban versus enoxaparin for thromboprophylaxis after total knee arthroplasty (RECORD-4): a randomized trial.. Lancet 2009; 373: 1673-1680.
  • 147 Connolly SJ, Ezekowitz MD, Yusuf S. et al RE-LY Steering Committee and Investigators. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med 2009; 361: 1139-1151.
  • 148 Schulman S, Kearon C, Kakkar AJ. et al RE-COVER Study Group. Dabigatran versus warfarin in the treatment of acute venous thromboembolism. N Engl J Med 2009; 361: 2342-2352.
  • 149 Lassen MR, Raskob GE, Gallus A. et al. Apixaban versus enoxaparin for thromboprophylaxis after knee replacement (ADVANCE-2): a randomized double-blind trial.. Lancet 2010; 375: 807-815.
  • 150 Boehringer Ingelheim Press Release. US FDA approves Pradaxa (dabigatran etexilate) – a breakthrough treatment for stroke prevention in non-valvular atrial fibrillation. Available at: http://www.boehringer-ingelheim.com/news/news_releases/press_releases/2010/20_october (Accessed December 7, 2010).
  • 151 Generics and Biosimilars Initiative. Biosimilars approved in Europe Posted 08/07/2011. www.gabionline.net/layout/set/print/content/view/full/1335 (Accessed October 10, 2011).
  • 152 Sassaki GL, Riter DS, Santana Filho AP. et al. A robust method to quantify low molecular weight contaminants in heparin: detection of tris(2-n-butoxyethyl) phosphate. Analyst. 2011 epub ahead of print.