Hemophilia A inhibitor treatment: the promise of engineered T-cell therapy

      Hemophilia A is a bleeding disorder caused by mutations in the gene encoding factor VIII (FVIII), a cofactor protein that is essential for normal blood clotting. Approximately, 1 in 3 patients with severe hemophilia A produce neutralizing antibodies (inhibitors) that block its biologic function in the clotting cascade. Current efforts to eliminate inhibitors consist of repeated FVIII injections under what is termed an “ITI” protocol (Immune Tolerance Induction). However, this method is extremely costly and approximately 30% of patients undergoing ITI do not achieve peripheral tolerance. Human T regulatory cells (Tregs) have been proposed as a new strategy to treat this antidrug antibody response, as well as other diseases. Polyclonal Tregs are nonspecific and could potentially cause general immunosuppression. Novel approaches to induce tolerance to FVIII include the use of engineered human and mouse antigen-specific Tregs, or alternatively antigen-specific cytotoxic cells, to delete, anergize, or kill FVIII-specific lymphocytes. In this review, we discuss the current state of engineered T-cell therapies, and we describe the recent progress in applying these therapies to induce FVIII-specific tolerance.


      BCR (B-cell receptor), CAR (chimeric antigen receptor), FVIII (factor VIII), HLA (human leukocyte antigen), ITI (immune tolerance induction), ITAMs (immunoreceptor tyrosine–based activation motifs), MHC (major histocompatibility complex), MBP (myelin basic protein), scFv (single-chain variable fragment), TCRs (T-cell receptors), Tregs (T regulatory cells)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Translational Research
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Adair P.
        • Su Y.
        • Scott D.W.
        Tolerance induction in hemophilia A animal models: battling inhibitors with antigen-specific immunotherapies.
        Discov Med. 2013; 15: 275-282
        • Scott D.W.
        • Pratt K.P.
        • Miao C.H.
        Progress toward inducing immunologic tolerance to factor VIII.
        Blood. 2013; 121: 4449-4456
      1. World Federation of Hemophilia. Available at: Accessed January 11, 2017.

        • Palta S.
        • Saroa R.
        • Palta A.
        Overview of the coagulation system.
        Indian J Anaesth. 2014; 58: 515-523
        • Fay P.J.
        Factor VIII structure and function.
        Int J Hematol. 2006; 83: 103-108
        • Osooli M.
        • Berntorp E.
        Inhibitors in haemophilia: what have we learned from registries? A systematic review.
        J Intern Med. 2015; 277: 1-15
        • Gouw S.C.
        • van den Berg H.M.
        • Oldenburg J.
        • et al.
        F8 gene mutation type and inhibitor development in patients with severe hemophilia A: systematic review and meta-analysis.
        Blood. 2012; 119: 2922-2934
        • d'Oiron R.
        • Lavergne J.M.
        • Lavend’homme R.
        • et al.
        Deletion of alanine 2201 in the FVIII C2 domain results in mild hemophilia A by impairing FVIII binding to VWF and phospholipids and destroys a major FVIII antigenic determinant involved in inhibitor development.
        Blood. 2004; 103: 155-157
        • Ettinger R.A.
        • James E.A.
        • Kwok W.W.
        • Thompson A.R.
        • Pratt K.P.
        HLA-DR-restricted T-cell responses to factor VIII epitopes in a mild haemophilia A family with missense substitution A2201P.
        Haemophilia. 2010; 16: 44-55
        • James E.A.
        • Kwok W.W.
        • Ettinger R.A.
        • Thompson A.R.
        • Pratt K.P.
        T-cell responses over time in a mild hemophilia A inhibitor subject: epitope identification and transient immunogenicity of the corresponding self-peptide.
        J Thromb Haemost. 2007; 5: 2399-2407
        • Scott D.W.
        Why do immunology research in hemophilia?.
        Cell Immunol. 2016; 301: 1
        • Spiegel Jr., P.C.
        • Jacquemin M.
        • Saint-Remy J.M.
        • Stoddard B.L.
        • Pratt K.P.
        Structure of a factor VIII C2 domain-immunoglobulin G4kappa Fab complex: identification of an inhibitory antibody epitope on the surface of factor VIII.
        Blood. 2001; 98: 13-19
        • Kasper C.K.
        • Pool J.G.
        Letter: Measurement of mild factor VIII inhibitors in Bethesda units.
        Thromb Diath Haemorrh. 1975; 34: 875-876
        • Guelcher C.J.
        Evolution of the treatments for hemophilia.
        J Infus Nurs. 2016; 39: 218-224
        • Meeks S.L.
        • Batsuli G.
        Hemophilia and inhibitors: current treatment options and potential new therapeutic approaches.
        Hematology Am Soc Hematol Educ Program. 2016; 2016: 657-662
        • Caspi R.
        Autoimmunity in the immune privileged eye: pathogenic and regulatory T cells.
        Immunol Res. 2008; 42: 41-50
        • Porter D.L.
        • Levine B.L.
        • Kalos M.
        • Bagg A.
        • June C.H.
        Chimeric antigen receptor-modified T cells in chronic lymphoid leukemia.
        N Engl J Med. 2011; 365: 725-733
        • Kochenderfer J.N.
        • Yu Z.
        • Frasheri D.
        • Restifo N.P.
        • Rosenberg S.A.
        Adoptive transfer of syngeneic T cells transduced with a chimeric antigen receptor that recognizes murine CD19 can eradicate lymphoma and normal B cells.
        Blood. 2010; 116: 3875-3886
        • Gross G.
        • Waks T.
        • Eshhar Z.
        Expression of immunoglobulin-T-cell receptor chimeric molecules as functional receptors with antibody-type specificity.
        Proc Natl Acad Sci U S A. 1989; 86: 10024-10028
        • Gross G.
        • Gorochov G.
        • Waks T.
        • Eshhar Z.
        Generation of effector T cells expressing chimeric T cell receptor with antibody type-specificity.
        Transplant Proc. 1989; 21: 127-130
        • Eshhar Z.
        Tumor-specific T-bodies: towards clinical application.
        Cancer Immunol Immunother. 1997; 45: 131-136
        • Eshhar Z.
        The T-body approach: redirecting T cells with antibody specificity.
        Handb Exp Pharmacol. 2008; : 329-342
        • Finney H.M.
        • Lawson A.D.
        • Bebbington C.R.
        • Weir A.N.
        Chimeric receptors providing both primary and costimulatory signaling in T cells from a single gene product.
        J Immunol. 1998; 161: 2791-2797
        • Imai C.
        • Mihara K.
        • Andreansky M.
        • et al.
        Chimeric receptors with 4-1BB signaling capacity provoke potent cytotoxicity against acute lymphoblastic leukemia.
        Leukemia. 2004; 18: 676-684
        • Long A.H.
        • Haso W.M.
        • Shern J.F.
        • et al.
        4-1BB costimulation ameliorates T cell exhaustion induced by tonic signaling of chimeric antigen receptors.
        Nat Med. 2015; 21: 581-590
        • Porter D.L.
        • Frey N.V.
        • Melenhorst J.J.
        • et al.
        Randomized, Phase II dose Optimization Study of chimeric antigen receptor modified T cells directed against CD19 (CTL019) in patients with relapsed, refractory CLL.
        Blood. 2014; 124: 1982
        • Scholler J.
        • Brady T.L.
        • Binder-Scholl G.
        • et al.
        Decade-long safety and function of retroviral-modified chimeric antigen receptor T cells.
        Sci Transl Med. 2012; 4: 132ra53
        • Grupp S.A.
        • Kalos M.
        • Barrett D.
        • et al.
        Chimeric antigen receptor-modified T cells for acute lymphoid leukemia.
        N Engl J Med. 2013; 368: 1509-1518
        • Maude S.L.
        • Frey N.
        • Shaw P.A.
        • et al.
        Chimeric antigen receptor T cells for sustained remissions in leukemia.
        N Engl J Med. 2014; 371: 1507-1517
        • Kochenderfer J.N.
        • Dudley M.E.
        • Kassim S.H.
        • et al.
        Chemotherapy-refractory diffuse large B-cell lymphoma and indolent B-cell malignancies can be effectively treated with autologous T cells expressing an anti-CD19 chimeric antigen receptor.
        J Clin Oncol. 2015; 33: 540-549
        • Schuster S.J.
        • Svoboda J.
        • Dwivedy Nasta S.
        • et al.
        Sustained remissions following chimeric antigen receptor modified T cells directed against CD19 (CTL019) in patients with relapsed or refractory CD19+ Lymphomas.
        Blood. 2015; 126: 183
        • Fesnak A.D.
        • June C.H.
        • Levine B.L.
        Engineered T cells: the promise and challenges of cancer immunotherapy.
        Nat Rev Cancer. 2016; 16: 566-581
      2. 2016 Ongoing Clinical Trials in United States. NCT02937103 (CD123); NCT02935153 (CD22); NCT02742727(CD7); NCT02954445 (BCMA); NCT02958410 (CD30); NCT02958397 (CD33); NCT01886976 (CD138); NCT02958384 (LeY); NCT02919046 (GD2); NCT02311621(CD171); NCT02844062 (EGFRvIII); NCT02575261(EphA2); NCT02713984 (HER2); NCT02744287 (PSCA); NCT02349724(CEA); NCT02541370 (CD133); NCT02617134 (Muc1); NCT02876978 (GPC3); NCT02862704 (MG7); NCT02915445 (EpCAM); NCT02706392 (ROR1); NCT01583686 (Mesothelin); NCT01722149 (FAP); NCT02830724 (CD70); NCT01140373 (PSMA)]. Available at: Accessed December 8, 2016.

        • Arellano B.
        • Graber D.J.
        • Sentman C.L.
        Regulatory T cell-based therapies for autoimmunity.
        Discov Med. 2016; 22: 73-80
        • Hori S.
        • Haury M.
        • Coutinho A.
        • Demengeot J.
        Specificity requirements for selection and effector functions of CD25+4+ regulatory T cells in anti-myelin basic protein T cell receptor transgenic mice.
        Proc Natl Acad Sci U S A. 2002; 99: 8213-8218
        • Masteller E.L.
        • Warner M.R.
        • Tang Q.
        • Tarbell K.V.
        • McDevitt H.
        • Bluestone J.A.
        Expansion of functional endogenous antigen-specific CD4+CD25+ regulatory T cells from nonobese diabetic mice.
        J Immunol. 2005; 175: 3053-3059
        • Roncarolo M.G.
        • Battaglia M.
        Regulatory T-cell immunotherapy for tolerance to self antigens and alloantigens in humans.
        Nat Rev Immunol. 2007; 7: 585-598
        • Tang Q.
        • Henriksen K.J.
        • Bi M.
        • et al.
        In vitro-expanded antigen-specific regulatory T cells suppress autoimmune diabetes.
        J Exp Med. 2004; 199: 1455-1465
        • Duraiswamy J.
        • Freeman G.J.
        • Coukos G.
        Therapeutic PD-1 pathway blockade augments with other modalities of immunotherapy T-cell function to prevent immune decline in ovarian cancer.
        Cancer Res. 2013; 73: 6900-6912
        • MacDonald K.G.
        • Hoeppli R.E.
        • Huang Q.
        • et al.
        Alloantigen-specific regulatory T cells generated with a chimeric antigen receptor.
        J Clin Invest. 2016; 126: 1413-1424
        • Sarkar D.
        • Biswas M.
        • Liao G.
        • et al.
        Ex vivo expanded autologous polyclonal regulatory T cells suppress inhibitor formation in hemophilia.
        Mol Ther Methods Clin Dev. 2014; 1 (
        • Hull C.M.
        • Nickolay L.E.
        • Estorninho M.
        • et al.
        Generation of human islet-specific regulatory T cells by TCR gene transfer.
        J Autoimmun. 2017; 79: 63-73
        • Boardman D.A.
        • Philippeos C.
        • Fruhwirth G.O.
        • et al.
        Expression of a chimeric antigen receptor specific for donor HLA class I Enhances the potency of human regulatory T cells in preventing human Skin transplant rejection.
        Am J Transplant. 2017; 17: 931-943
        • Braza F.
        • Durand M.
        • Degauque N.
        • Brouard S.
        Regulatory T cells in Kidney transplantation: new Directions?.
        Am J Transplant. 2015; 15: 2288-2300
        • Ferreira M.C.
        • de Oliveira R.T.
        • da Silva R.M.
        • Blotta M.H.
        • Mamoni R.L.
        Involvement of regulatory T cells in the immunosuppression characteristic of patients with paracoccidioidomycosis.
        Infect Immun. 2010; 78: 4392-4401
        • Belmonte N.
        • Gertner-dardenne J.
        • Foussat A.
        Regulatory T cell engineered with chimeric antigen receptor (CAR-Treg) for Inflammatory and autoimmune diseases.
        Cytotherapy. 2016; 18: S95
        • Aledort L.M.
        • Evatt B.L.
        • Lusher J.M.
        • Brownstein A.P.
        HIV and hemophilia.
        J Thromb Haemost. 2007; 5: 607-610
        • Bray G.L.
        • Kroner B.L.
        • Arkin S.
        • et al.
        Loss of high-responder inhibitors in patients with severe hemophilia A and human immunodeficiency virus type 1 infection: a report from the Multi-Center Hemophilia Cohort Study.
        Am J Hematol. 1993; 42: 375-379
        • Qian J.
        • Collins M.
        • Sharpe A.H.
        • Hoyer L.W.
        Prevention and treatment of factor VIII inhibitors in murine hemophilia A.
        Blood. 2000; 95: 1324-1329
        • Qian J.
        • Burkly L.C.
        • Smith E.P.
        • et al.
        Role of CD154 in the secondary immune response: the reduction of pre-existing splenic germinal centers and anti-factor VIII inhibitor titer.
        Eur J Immunol. 2000; 30: 2548-2554
        • Kim Y.C.
        • Zhang A.H.
        • Su Y.
        • et al.
        Engineered antigen-specific human regulatory T cells: immunosuppression of FVIII-specific T- and B-cell responses.
        Blood. 2015; 125: 1107-1115
        • Yoon J.
        • Schmidt A.
        • Zhang A.H.
        • Konigs C.
        • Kim Y.C.
        • Scott D.W.
        FVIII-specific human chimeric antigen receptor T-regulatory cells suppress T- and B-cell responses to FVIII.
        Blood. 2017; 129: 238-245
        • Parvathaneni K.
        • Zhang A.
        • Kim Y.C.
        • Scott D.W.
        BAR-CD8 T-Cell mediated targeted killing of inhibitor producing FVIII-specific B cells.
        Blood. 2015; 126: 294
        • Zhang A.-H.
        • Parvathaneni K.
        • Yoon J.
        • Kim Y.
        • Scott D.W.
        Targeting antigen-specific B cells using BAR-transduced cytotoxic and regulatory T cells.
        J Immunol. 2016; 196: 70.7
        • Ettinger R.A.
        • James E.A.
        • Kwok W.W.
        • Thompson A.R.
        • Pratt K.P.
        Lineages of human T-cell clones, including T helper 17/T helper 1 cells, isolated at different stages of anti-factor VIII immune responses.
        Blood. 2009; 114: 1423-1428
        • Theaker S.M.
        • Rius C.
        • Greenshields-Watson A.
        • et al.
        T-cell libraries allow simple parallel generation of multiple peptide-specific human T-cell clones.
        J Immunol Methods. 2016; 430: 43-50
        • Kahle J.
        • Orlowski A.
        • Stichel D.
        • et al.
        Epitope mapping via selection of anti-FVIII antibody-specific phage-presented peptide ligands that mimic the antibody binding sites.
        Thromb Haemost. 2015; 113: 396-405
        • Naumann A.
        • Scherger A.K.
        • Neuwirth J.
        • et al.
        Selection and characterisation of FVIII-specific single chain variable fragments.
        Hamostaseologie. 2013; 33: S39-S45
        • Fu R.
        • Lyle M.J.
        • Wang X.
        • Miao C.H.
        Factor VIII-specific CAR regulatory T cells modulate murine anti-factor VIII immune responses.
        J Immunol. 2016; 196: 126.13
        • Ellebrecht C.T.
        • Bhoj V.G.
        • Nace A.
        • et al.
        Reengineering chimeric antigen receptor T cells for targeted therapy of autoimmune disease.
        Science. 2016; 353: 179-184
        • Kalos M.
        • Levine B.L.
        • Porter D.L.
        • et al.
        T cells with chimeric antigen receptors have potent antitumor effects and can establish memory in patients with advanced leukemia.
        Sci Transl Med. 2011; 3: 95ra73