Methods and compositions for inducing tolerance

Abstract

Provided herein are methods for inducing tolerance to an organ or tissue transplant in a patient. Specifically, provided herein are methods for inducing transient mixed chimerism in a transplant-eligible patient, the methods comprising administering to the patient an anti-CD2 antibody or antigen-binding fragment thereof, transplanting bone marrow from a donor into the patient, and administering to the patient at least one other agent before and / or after transplantation.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Patent Application No. 63 / 241,358, filed September 7, 2021, the disclosure of which is incorporated herein by reference in its entirety. Sequence Listing This application contains a computer readable sequence listing submitted herewith in XML file format, the entire contents of which are incorporated herein by reference in their entirety. The sequence listing XML file submitted with this application is named "14526-007-228_SEQ_LISTING.xml", was created on August 31, 2022, and is 36,184 bytes in size.

[0002] 1. Introduction Provided herein are methods for inducing tolerance to an organ or tissue transplant in a patient. Compositions for use with these methods and kits are also disclosed. [Background technology]

[0003] 2.Background technology The long-term outcomes of organ transplantation remain poor. Chronic rejection of the donor graft and health problems associated with long-term immunosuppressant use remain serious complications of the procedure. However, these complications can be overcome by inducing tolerance to the donor graft by the recipient's immune system. Tolerance avoids destructive immune reactions after transplantation without the need for systemic immunosuppressants.

[0004] Simultaneous kidney and bone marrow transplantation has been described. See, for example, Kawai et al. 2014, American Journal of Transplantation 14:1599-1611. This study demonstrated long-term stable kidney allograft survival without maintenance immunosuppressants. However, for optimal clinical outcomes, revisiting the conditioning regimen is necessary. The methods disclosed herein describe improved treatment regimens to provide consistent tolerance to organ or tissue transplantation.

[0005] Siplizumab is a humanized IgG1κ monoclonal antibody against the human CD2 glycoprotein, a receptor expressed on virtually all mature human T cells and the vast majority of thymocytes (Bierer BE, Burakoff SJ., Immunol Rev. 1989; 111: 267-294). CD2 promotes T cell adhesion to antigen-presenting cells through interaction with the ligand LFA-3 (CD58) (van der Merwe PA, Barclay AN, Mason DW, et al. Biochemistry. 1994; 33(33): 10149-10160). Binding of CD2 to LFA-3 also initiates a cascade of intracellular signals required for T cell activation, endowing this molecule with an important costimulatory function (Bockenstedt LK. et al., J Immunol. 1988; 141(6): 1904-1911; Binder, Christian, et al., (2020). CD2 Immunobiology. Front. Immunol. 11: 1090. doi: 10.3389 / fimmu.2020.01090).

[0006] Ligation of either siplizumab or its parent antibody (BTI-322 / Lo-CD2a) against human CD2 promotes T cell depletion via antibody-dependent cell-mediated cytotoxicity (ADCC), an effect that is particularly pronounced against activated T cells (Branco L. et al., Transplantation. 1999; 68(10): 1588-1596; Nizet Y, et al. Transplantation. 2000; 69(7): 1420-1428). In addition, these agents efficiently inhibit in vitro allogeneic mixed lymphocyte reactions (MLR), reducing responsiveness upon subsequent allogeneic restimulation while preserving responsiveness to nonspecific stimuli. This effect was found to be mediated, at least in part, by specific activation-associated T cell depletion (Latinne D.et al.,Int Immunol.1996;8(7):1113-1119;Xu Y.et al.,Clin Exp Immunol.2004;138(3):476-483;Podesta MA,Binder C,Sellberg F,et al.Siplizumab selectively depletes effector memory T cells and promotes a relative expansion of alloreactive regulatory T cells in vitro.Am J Transplant.2019;20:88-100.https: / / doi.org / 10.1111 / ajt.15533;Binder Christian,et al.(2020)Siplizumab,an Anti-CD2 Monoclonal Antibody,Induces a Unique Set of Immune Modulatory Effects Compared to Alemtuzumab and Rabbit AntiThymocyte Globulin In Vitro.Front. Immunol.11:592553.doi:10.3389 / fimmu.2020.592553).

[0007] Siplizumab has been used in conditioning regimens for tolerance induction following hematopoietic cell transplantation and simultaneous kidney and bone marrow transplantation (Dey, Bimalangshu, et al. Anti-tumour response despite loss of donor chimaerism in patients treated with non-myeloablative conditioning and allogeneic stem cell transplantation. British Journal of Haematology, 2005, 128, 351-359, doi:10.1111 / j.1365-2141.2004.05328.x; Shaffer, Juanita, et al. Regulatory T-cell recovery in recipients of haploidentical nonmyeloablative hematopoietic cell transplantation with a humanized anti-CD2 mAb, MEDI-507, with or without fludarabine. Exp Hematol.2007Jul;35(7):1140-52.doi:10.1016 / j.exphem.2007.03.018).

[0008] Siplizumab globally depletes T cells while enriching regulatory T cells (Tregs) early after transplantation. A significant early enrichment of regulatory T cells (Tregs) was observed during the T cell reconstitution phase in recipients of hematopoietic cell transplants to treat malignancies (Shaffer J.et al., Exp Hematol.2007;35(7):1140-1152) and CKBMT recipients (Andreola G.et al., Am J Transplant.2011;11(6):1236-1247) (Savage,Thomas,et al.,Early expansion of donor-specific Tregs in tolerant kidney transplant recipients.JCI Insight.2018Nov15;3(22):e124086.doi:10.1172 / jci.insight.124086;Sprangers,Ben,et al.Origin of Enriched regulatory t cells in patients receiving combined kidney / bone marrow transplantation to induce transplantation tolerance.Am J Transplant.2017Aug;17(8):2020-2032.doi:10.1111 / ajt.14251;LoCascio,Samuel,et al.Mixed Chimerism,Lymphocyte Recovery and Evidence for Early Donor-Specific Unresponsiveness in Patients Receiving CKBMT to Induce Tolerance. Transplantation.2010December27;90(12):1607-1615.doi:10.1097 / TP.0b013e3181ffbaff).

[0009] Previous studies have shown that anti-IL6R treatment has been observed to restore a physiological Treg / Th17 balance that may be important for clinical response in patients with rheumatoid arthritis when administered humanized IL6R antibodies (Schinnerling, et al., Clin Exp Immunol. 2017 189(1):12-20). Anti-IL6R treatment has been shown to promote the proliferation of protective Treg cells; Tada, BMC Musculoskelet Disord. 2016 17:290). Furthermore, the use of anti-IL6R blockade is effective in the treatment of cytokine release syndrome (CRS) (Brudno JN. and Kochenderfer JN. Blood. 2016 127(26):3321-30; Hay, K. Br J Haematol. 183(3):364-374. 2018). The use of anti-IL6R antibodies to block IL6 signaling has been approved by the FDA as a treatment for CRS in CAR-T cell patients (Le,et al.,Oncologist.2018(8):943-947.2018;Highlights of Prescribing Information;ACTEMRA®(tocilizumab) injection, for intravenous or subcutaneous use. Genentech,Inc.2017). Summary of the Invention

[0010] 3. Overview of the Invention Provided herein is a method for inducing transient mixed chimerism in a transplant-eligible patient, the method comprising administering an anti-CD2 antibody or antigen-binding fragment thereof to the patient, subjecting the patient to an organ or tissue transplant, infusing bone marrow cells from a donor into the patient, and administering one or more agents to the subject before and / or after transplant. In certain embodiments, the chimerism can persist for weeks to months after transplant surgery. In certain embodiments, the method includes a conditioning regimen and a post-operative regimen. In certain embodiments, the method induces tolerance in the recipient to the transplanted organ or tissue. This tolerance can be long-lasting or permanent, minimizing the risk of graft-versus-host disease.

[0011] Without wishing to be bound by theory, hematopoietic cells obtained from the donor's bone marrow can be infused into the recipient to create a state in which donor and recipient hematopoietic cells coexist. In combination with non-myeloablative conditioning, bone marrow transplantation results in recipient chimerism and induction of donor-specific tolerance. Advantages of this approach include avoiding ablation of the recipient's immune system and inhibiting the development of graft-versus-host disease without the need for the use of long-term systemic immunosuppressants.

[0012] In one aspect herein, a method for transplanting an organ or tissue from a donor to a subject is provided, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody or antigen-binding fragment thereof; c) administering to the subject fludarabine; d) transplanting the organ or tissue into the subject; and e) injecting bone marrow cells from the donor into the subject.

[0013] In one aspect herein, a method of transplanting an organ or tissue from a donor to a subject is provided, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody, or an antigen-binding fragment thereof; c) transplanting the organ or tissue to the subject; and d) injecting bone marrow cells from the donor into the subject, wherein the B cell depleting antibody is administered to the subject more than 7 days prior to transplant.

[0014] In one aspect herein, a method of transplanting an organ or tissue from a donor to a subject is provided, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody, or antigen-binding fragment thereof; c) transplanting the organ or tissue into the subject; and d) injecting bone marrow cells from the donor into the subject, wherein a first administration of the anti-CD2 antibody, or antigen-binding fragment thereof, is administered one day prior to transplantation.

[0015] In one aspect herein, a method of transplanting an organ or tissue from a donor to a subject is provided, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody, or antigen-binding fragment thereof; c) transplanting the organ or tissue to the subject; and d) injecting bone marrow cells from the donor into the subject, wherein the anti-CD2 antibody, or antigen-binding fragment thereof, is administered to the subject more than 2 days prior to transplant.

[0016] In one aspect herein, a method is provided for minimizing chimeric transition syndrome in a subject in need of an organ or tissue transplant, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody or antigen-binding fragment thereof; c) administering to the subject fludarabine; d) transplanting the organ or tissue into the subject; and e) infusing bone marrow cells from a donor into the subject.

[0017] In one aspect herein, a method is provided for minimizing chimeric transition syndrome in a subject in need of an organ or tissue transplant, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody, or antigen-binding fragment thereof; c) transplanting the organ or tissue to the subject; and d) infusing bone marrow cells from a donor into the subject, wherein the B cell depleting antibody is administered to the subject more than 7 days prior to the transplant.

[0018] In one aspect herein, a method is provided for minimizing chimeric transition syndrome in a subject in need of an organ or tissue transplant, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody, or antigen-binding fragment thereof; c) transplanting the organ or tissue into the subject; and d) infusing bone marrow cells from a donor into the subject, wherein a first administration of the anti-CD2 antibody, or antigen-binding fragment thereof, is administered one day prior to the transplant.

[0019] In one aspect herein, a method is provided for minimizing chimeric transition syndrome in a subject in need of an organ or tissue transplant, the method comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody, or antigen-binding fragment thereof; c) transplanting the organ or tissue into the subject; and d) infusing bone marrow cells from a donor into the subject, wherein the anti-CD2 antibody, or antigen-binding fragment thereof, is administered to the subject more than 2 days prior to the transplant.

[0020] In some embodiments, the B cell depleting antibody is administered to the subject 9 days prior to transplant. In some embodiments, the B cell depleting antibody is administered to the subject 9 days and 2 days prior to transplant. In some embodiments, the B cell depleting antibody is administered to the subject 9 days and 2 days prior to transplant and 5 days and 12 days after transplant. In some embodiments, the B cell depleting antibody is rituximab. In some embodiments, the B cell depleting antibody is administered at a dose of about 375 mg / m 2 In some embodiments, the B cell depleting antibody is not administered 7 days prior to transplant. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject 1 day before transplantation, on the day of transplantation, and 1 day after transplantation. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject 6 days before transplantation, 1 day before transplantation, on the day of transplantation, and 1 day after transplantation. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject 6 days before transplantation, 1 day before transplantation, on the day of transplantation, 1 day after transplantation, and 6 days after transplantation. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is siplizumab. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject at a dose of about 0.6 mg / kg. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof comprises a) a heavy chain variable region CDR1 of SEQ ID NO:3, b) a heavy chain variable region CDR2 of SEQ ID NO:4, c) a heavy chain variable region CDR3 of SEQ ID NO:5, d) a light chain variable region CDR1 of SEQ ID NO:6, e) a light chain variable region CDR2 of SEQ ID NO:7, and f) a light chain variable region CDR3 of SEQ ID NO:8. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is a humanized antibody. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject at a dose of greater than about 0.1 mg / kg. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject at a dose of about 0.6 mg / kg. In some embodiments, each dose of the anti-CD2 antibody or antigen-binding fragment thereof administered to the subject comprises the same dose.

[0021] In some embodiments, the methods provided herein further comprise administering a non-myeloablative conditioning agent to the subject. In some embodiments, the non-myeloablative conditioning agent comprises an immunosuppressant. In some embodiments, the immunosuppressant is cyclophosphamide. In some embodiments, the immunosuppressant is administered to the subject 5 days and 4 days prior to transplant. In some embodiments, the immunosuppressant is administered to the subject at a dose of about 60 mg / kg. In some embodiments, the immunosuppressant is administered to the subject at a dose of about 22.5 mg / kg. In some embodiments, the non-myeloablative conditioning agent comprises an anti-neoplastic agent. In some embodiments, the anti-neoplastic agent is a chemotherapeutic agent. In some embodiments, the anti-neoplastic agent is fludarabine. In some embodiments, the anti-neoplastic agent is administered to the subject 6 days, 5 days, 4 days, and 3 days prior to transplant. In some embodiments, the fludarabine is administered to the subject 6 days, 5 days, 4 days, and 3 days prior to transplant. In some embodiments, the anti-cancer agent is at about 10 mg / m 2 In some embodiments, fludarabine is administered to the subject at a dose of about 10 mg / m 2 is administered to the subject at a dose of

[0022] In some embodiments, injecting bone marrow cells is performed on the same day as transplantation. In some embodiments, the method further comprises providing thymic irradiation to the subject. In some embodiments, thymic irradiation is provided to the subject one day before transplantation. In some embodiments, thymic irradiation is provided to the subject at about 7 Gy.

[0023] In some embodiments, the methods provided herein further comprise administering an anti-IL6R antibody to the subject. In some embodiments, the anti-IL6R antibody is tocilizumab. In some embodiments, the anti-IL6R antibody is administered to the subject at a dose of about 8 mg / kg. In some embodiments, the anti-IL6R antibody is administered to the subject 7 days and 14 days after transplantation. In some embodiments, the anti-IL6R antibody is administered to the subject after transplantation. In some embodiments, the anti-IL6R antibody is administered to the subject about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, the anti-IL6R antibody is administered to the subject about 3-4 months after transplantation.

[0024] In some embodiments, the methods provided herein further include administering a steroid to the subject. In some embodiments, the steroid is administered to the subject on the day of transplantation. In some embodiments, the steroid is administered to the subject for about 20 days after transplantation. In some embodiments, the steroid is administered to the subject for about 6 months after transplantation. In some embodiments, the steroid is a corticosteroid. In some embodiments, the steroid is administered to the subject after transplantation. In some embodiments, the corticosteroid is administered to the subject after transplantation. In some embodiments, the steroid is administered to the subject about or at least about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, the corticosteroid is administered to the subject about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, the steroid is administered to the subject about 3-4 months after transplantation. In some embodiments, the corticosteroid is administered to the subject about 3-4 months after transplantation.

[0025] In some embodiments, the methods provided herein further include administering tacrolimus to the subject. In some embodiments, tacrolimus is administered to the subject at a dose of about 4-11 ng / mL. In some embodiments, tacrolimus is administered to the subject at a dose of about 8-10 ng / mL. In some embodiments, tacrolimus is administered to the subject on the day of transplantation. In some embodiments, tacrolimus is administered to the subject about 9-12 months after transplantation. In some embodiments, tacrolimus is administered to the subject about 1 month after transplantation. In some embodiments, tacrolimus is administered to the subject after transplantation. In some embodiments, tacrolimus is administered to the subject about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, tacrolimus is administered to the subject about 3-4 months after transplantation.

[0026] In some embodiments, the methods provided herein further include administering mycophenolate mofetil to the subject. In some embodiments, mycophenolate mofetil is administered to the subject at a dose of about 2 g / day. In some embodiments, mycophenolate mofetil is administered to the subject on the day of transplantation. In some embodiments, mycophenolate mofetil is administered to the subject about 2 months after transplantation. In some embodiments, mycophenolate mofetil is administered to the subject after transplantation. In some embodiments, mycophenolate mofetil is administered to the subject about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, mycophenolate mofetil is administered to the subject about 3-4 months after transplantation.

[0027] In some embodiments, the methods provided herein further include administering sirolimus to the subject. In some embodiments, sirolimus is administered to the subject at a dose of about 5-8 ng / mL. In some embodiments, sirolimus is administered to the subject at about 1 month after transplantation or about 1 month after transplantation. In some embodiments, sirolimus is administered to the subject up to 12 months after transplantation. In some embodiments, sirolimus is administered to the subject after transplantation. In some embodiments, sirolimus is administered to the subject about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, sirolimus is administered to the subject about 3-4 months after transplantation.

[0028] In some embodiments, the methods provided herein induce mixed chimerism in a subject. In some embodiments, the mixed chimerism is characterized by a percentage of donor cells in the lymphohematopoietic system of the subject being at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or at least about 90%. In some embodiments, the mixed chimerism lasts for about or up to about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, or up to 12 months. In some embodiments, the ratio of FoxP3+ T cells to CD4+ T cells is increased in the subject compared to the ratio of FoxP3+ T cells to CD4+ T cells in the absence of an anti-CD2 antibody or an antigen-binding fragment thereof. In some embodiments, FoxP3+ expression persists in actively proliferating T cells after the last administration of an anti-CD2 antibody or antigen-binding fragment thereof.

[0029] In some embodiments, the methods provided herein reduce the risk of graft-versus-host disease in a subject. In some embodiments, the organ or tissue is a kidney. In some embodiments, the subject is a human. In some embodiments, the donor is a human. In some embodiments, the methods provided herein induce tolerance to the transplanted organ or tissue in a subject. [Brief description of the drawings]

[0030] 4. Brief description of the drawings These and other objects, features and advantages will become apparent from the following description of specific embodiments of the invention, as illustrated in the accompanying drawings, which are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention.

[0031] [Figure 1] A diagram outlining tolerance.

[0032] [Diagram 2] A table showing the evaluation schedule.

[0033] [Diagram 3] A graph outlining tolerance research.

[0034] [Figure 4] A table showing the evaluation schedule.

[0035] [Diagram 5] Graph showing IL-6 mAb (e.g., tocilizumab) treatment for chimeric transition syndrome (CTS). The graph shows administration of an anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) on days -6, -1, 0, and 1 (day 0 being the day of transplant), and administration of IL-6 mAb (e.g., tocilizumab) only if chimeric transition syndrome (CTS) occurs.

[0036] [Figure 6]Graph showing prophylactic IL-6 mAb (e.g., tocilizumab) treatment on days 7 and 14, and administration of an anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) on days -6, -1, 0, and 1 (day 0 being the day of transplant).

[0037] [Figure 7] Graph showing anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) administered 6 days prior to transplant, 1 day prior to transplant, on the day of transplant, 1 day after transplant, and 6 days after transplant, as well as prophylactic anti-IL-6R mAb (e.g., toburizumab) treatment on days 7 and 14. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] 5. MODE FOR CARRYING OUT THEINVENTION Described herein are methods for inducing tolerance of an organ or tissue transplant recipient's immune system to the transplanted organ or tissue without the need for ongoing immunosuppressive therapy. Provided herein are methods for simultaneous organ / tissue and bone marrow transplantation preceded by a specific conditioning treatment regimen and followed by a specific post-operative treatment regimen. The regimen can be a non-myeloablative procedure that includes administration of antibodies, immunosuppressants, and radiation to deplete the recipient's immune cells. In certain embodiments, the components of the regimen can be altered as described herein to achieve mixed chimerism in the recipient. In certain embodiments, the components of the regimen can be altered as described herein to achieve induction of tolerance of an organ / tissue transplant recipient's immune system to the transplanted organ / tissue without the need for ongoing immunosuppressive therapy.

[0039] Organ or tissue transplants and bone marrow infusions for use with the methods provided herein are described in Section 5.2. Initial conditioning regimens and / or post-operative treatments for use with the current methods are described in Section 5.3. Transplants and bone marrow infusions are described in Sections 5.4 and 5.5. Methods for evaluating clinical outcomes are described in Section 5.6. Pharmaceutical compositions are described in Section 5.7. Kits are described in Section 5.8. Examples of the methods provided herein are described in Section 6.

[0040] In certain embodiments, individuals who have been selected for or have received an organ or tissue transplant may be treated using the methods described herein. Without being bound by theory, a treatment regimen is followed to induce a state of transient mixed chimerism. In certain embodiments, the treatment regimen is Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) 6 days, 1 day, the day of, and 1 day after transplant surgery, or administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) 6 days, 1 day, the day of, 1 day after, and 6 days after transplant surgery; c. Administer cyclophosphamide (60 mg / kg) 5 and 4 days before transplantation; d. Administering thymic irradiation (e.g., 7 Gy) one day prior to transplantation; e. Administering tocilizumab (e.g., 8 mg / kg) if chimeric migration syndrome occurs or on days 7 and 14 after transplant surgery.

[0041] In some embodiments, the treatment regimen further comprises administering tacrolimus (e.g., after transplant (e.g., at a dose of about 4-11 ng / mL), about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplant, and / or 4-11 ng / mL on the day of transplant and for 9-12 months after transplant). In some embodiments, the treatment regimen further comprises administering mycophenolate mofetil (MMF) (e.g., after transplant (e.g., at a dose of about 2 g / day), about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplant, and / or about 2 g / day on the day of transplant and for 2 months after transplant). In some embodiments, the treatment regimen further comprises administering a steroid or corticosteroid (e.g., after transplant, about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplant, and / or on the day of transplant and for 20 days after transplant).

[0042] In certain embodiments, the treatment regimen comprises: Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) 6 days, 1 day, the day of, and 1 day after transplant surgery; c. Administer cyclophosphamide (60 mg / kg) 5 and 4 days before transplantation; d. Administering thymic irradiation (e.g., 7 Gy) one day prior to transplantation; e. subjecting the patient to organ or tissue (e.g., kidney) transplantation and bone marrow cell infusion; f. Administer tocilizumab (e.g., 8 mg / kg) only if CTS occurs; and g. Tacrolimus (e.g., 4-11 ng / mL) should be administered on the day of transplant and for 9-12 months after transplant; h. MMF (e.g., 2 g / day) should be administered on the day of transplantation and for 2 months after transplantation; i. Administering corticosteroids on the day of transplant and for 20 days following transplant.

[0043] In certain embodiments, the treatment regimen comprises: Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) 6 days, 1 day, the day of, and 1 day after transplant surgery; c. Administer cyclophosphamide (60 mg / kg) 5 and 4 days before transplantation; d. Administering thymic irradiation (e.g., 7 Gy) one day prior to transplantation; e. Subjecting patients to organ or tissue (e.g., kidney) transplants and bone marrow cell infusions.

[0044] In some embodiments, tocilizumab (e.g., 8 mg / kg) is administered after organ or tissue transplant. In some embodiments, tacrolimus (e.g., 4-11 ng / mL) is administered after organ or tissue transplant. In some embodiments, MMF (e.g., 2 g / day) is administered after organ or tissue transplant. In some embodiments, a steroid or corticosteroid is administered after organ or tissue transplant. In some embodiments, tocilizumab, tacrolimus, MMF, a steroid and / or a corticosteroid is administered to the subject about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplant.

[0045] In certain embodiments, the treatment regimen comprises: Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) 6 days, 1 day, the day of, and 1 day after transplant surgery; c. Administer cyclophosphamide (60 mg / kg) 5 and 4 days before transplantation; d. Administering thymic irradiation (e.g., 7 Gy) one day prior to transplantation; e. subjecting the patient to organ or tissue (e.g., kidney) transplantation and bone marrow cell infusion; f. administering tocilizumab (e.g., 8 mg / kg) 7 and 14 days after transplantation; g. Tacrolimus (e.g., 4-11 ng / mL) should be administered on the day of transplant and for 9-12 months after transplant; h. MMF (e.g., 2 g / day) should be administered on the day of transplantation and for 2 months after transplantation; i. Administering corticosteroids on the day of transplant and for 20 days following transplant.

[0046] In certain embodiments, the treatment regimen comprises: Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) 6 days, 1 day, the day of, 1 day, and 6 days after transplant surgery; c. Administer cyclophosphamide (60 mg / kg) 5 and 4 days before transplantation; d. Administering thymic irradiation (e.g., 7 Gy) one day prior to transplantation; e. subjecting the patient to organ or tissue (e.g., kidney) transplantation and bone marrow cell infusion; f. administering tocilizumab (e.g., 8 mg / kg) 7 and 14 days after transplantation; g. Tacrolimus (e.g., 4-11 ng / mL) should be administered on the day of transplant and for 9-12 months after transplant; h. MMF (e.g., 2 g / day) should be administered on the day of transplantation and for 2 months after transplantation; i. Administering corticosteroids on the day of transplant and for 20 days following transplant.

[0047] In certain embodiments, the treatment regimen comprises: Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) one day before, on the day of, and one day after transplantation; c) administering cyclophosphamide (22.5 mg / kg) 5 and 4 days before transplantation; d. Fludarabine (e.g., 10 mg / m) 6, 5, 4, and 3 days before transplant surgery. 2 ) and e. Administering thymic irradiation (eg, 7 Gy) one day prior to transplant surgery.

[0048] In some embodiments, the treatment regimen further comprises administering tacrolimus (e.g., after transplant (e.g., at a dose of about 8-10 ng / mL), about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplant, and / or 8-10 ng / mL on the day of transplant and for 1 month after transplant). In some embodiments, the treatment regimen further comprises administering sirolimus or an mTOR inhibitor (e.g., after transplantation (e.g., at a dose of about 5-8 ng / mL), about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation, and / or 5-8 ng / mL from 1 month after transplantation and up to 12 months after transplantation). In some embodiments, the treatment regimen further comprises administering a corticosteroid (e.g., after transplantation, about, or at least about, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation, and / or from the day of transplantation and up to 6 months after transplantation).

[0049] In certain embodiments, the treatment regimen comprises: Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) one day before, on the day of, and one day after transplantation; c) administering cyclophosphamide (22.5 mg / kg) 5 and 4 days before transplantation; d. Fludarabine (e.g., 10 mg / m) 6, 5, 4, and 3 days before transplant surgery. 2 ) and e. administering thymic irradiation (e.g., 7 Gy) one day prior to transplantation; f. subjecting the patient to organ or tissue (e.g., kidney) transplantation and bone marrow cell infusion; g. Administer tacrolimus (e.g., 8-10 ng / mL) on the day of transplantation and for one month after transplantation; h. Administering sirolimus (e.g., 5-8 ng / mL) or an mTOR inhibitor for 1 month post-transplant and up to 12 months post-transplant; and i. Administering corticosteroids on the day of transplant and for six months following transplant.

[0050] In certain embodiments, the treatment regimen comprises: Rituximab (375 mg / m 2 ) to the recipient; b. administering an anti-CD2 antibody or antigen-binding fragment thereof (e.g., about 0.6 mg / kg siplizumab) one day before, on the day of, and one day after transplantation; c) administering cyclophosphamide (22.5 mg / kg) 5 and 4 days before transplantation; d. Fludarabine (e.g., 10 mg / m) 6, 5, 4, and 3 days before transplant surgery. 2 ) and e. administering thymic irradiation (e.g., 7 Gy) one day prior to transplantation; f. Subjecting patients to organ or tissue (e.g., kidney) transplants and bone marrow cell infusions.

[0051] In some embodiments, tacrolimus (e.g., 8-10 ng / mL) is administered to the subject post-transplant (e.g., post-transplant, about or at least about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplant). In some embodiments, sirolimus (e.g., 5-8 ng / mL) or an mTOR inhibitor is administered to the subject post-transplant (e.g., post-transplant, about or at least about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplant). In some embodiments, the steroid or corticosteroid is administered to the subject after transplantation (e.g., after transplantation, about, or at least about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation).

[0052] In some embodiments, provided herein are methods for transplanting an organ and / or tissue from a donor into a subject or for minimizing chimeric transition syndrome in a subject in need of an organ or tissue transplant, the methods comprising: a) administering a B cell depleting antibody to the subject; b) administering an anti-CD2 antibody or antigen-binding fragment thereof to the subject; c) transplanting the organ or tissue into the subject; and d) injecting bone marrow cells from the donor into the subject. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject more than 2 days prior to organ and / or tissue transplant. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is not administered to the subject 2 days prior to organ and / or tissue transplant. In some embodiments, the B cell depleting antibody is administered to the subject more than 7 days prior to organ and / or tissue transplant. In some embodiments, the first administration of the anti-CD2 antibody or antigen-binding fragment thereof is 1 day prior to organ and / or tissue transplant.

[0053] In some embodiments, provided herein are methods for transplanting an organ and / or tissue from a donor into a subject or for minimizing chimeric transition syndrome in a subject in need of an organ or tissue transplant, the methods comprising: a) administering to the subject a B cell depleting antibody; b) administering to the subject an anti-CD2 antibody or antigen-binding fragment thereof; c) administering to the subject fludarabine; d) transplanting the organ or tissue into the subject; and e) injecting bone marrow cells from the donor into the subject.

[0054] In some embodiments, the treatment regimens described herein can be modified, in particular the route of administration, dosage, and exact timing of the various active pharmaceutical ingredients, to suit the particular circumstances of the transplant and to achieve induction of tolerance of the immune system of the organ transplant recipient to the transplanted organ without the need for ongoing immunosuppressive therapy. In some embodiments, the treatment regimens described herein can be modified, e.g., to administer a comparable agent instead of or in addition to the agents described herein (e.g., in some embodiments, a B cell depleting antibody is administered to the subject instead of or in addition to rituximab; an anti-IL-6R antibody is administered to the subject instead of or in addition to tocilizumab; an anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject instead of or in addition to siplizumab; an anti-neoplastic agent is administered to the subject instead of or in addition to fludarabine; an anti-proliferative agent is administered to the subject instead of or in addition to MMF; an immunosuppressant is administered to the subject instead of or in addition to cyclophosphamide; an immunosuppressant is administered to the subject instead of or in addition to tacrolimus; an mTOR inhibitor is administered to the subject instead of or in addition to sirolimus; and / or a steroid is administered to the subject instead of or in addition to a corticosteroid). Without being bound by theory, the treatment regimen is modified to still produce transient mixed chimerism. In certain embodiments, transient mixed chimerism is characterized by the percentage of donor cells in lymphohematopoietic system being at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or at least about 90%. In certain embodiments, transient mixed chimerism lasts for up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or up to 12 months. The ratio of FoxP3+ T cells to CD4+ T cells can be increased in transplant recipients compared to the ratio of FoxP3+ T cells to CD4+ T cells in the absence of anti-CD2 antibody.FoxP3+ expression can persist in actively proliferating T cells after the last dose of anti-CD2 antibody. Mixed chimerism can be assayed, for example, as described in Sections 5.6 and 6.

[0055] 5.1 Recipient As used herein, the terms "subject," "recipient," and "patient" are used interchangeably. In some embodiments, the subject is a mammal. In some embodiments, the subject or subject in need is a subject who has or is expected to develop an immune-related disorder or disease. In some embodiments, the subject or subject in need is a subject who has or will undergo transplant surgery. In some embodiments, the subject or subject in need is a subject who has a chronic or acute inflammatory disorder of the immune system. In some embodiments, the subject is a primate. In certain embodiments, the subject is a human. In some embodiments, the subject is an adult. In some embodiments, the subject is a child. In some embodiments, the subject is a pediatric patient. In some embodiments, the subject is a young human. In some embodiments, the subject is at least 5, 10, 15, 18, 21, 50, 60, 65, 70, or over 70 years old. In some embodiments, the subject is at most 5, 10, 15, 18, or 21 years old. In some embodiments, the subject has not undergone prior treatment associated with an organ transplant or for an immune-related disorder or disease. In some embodiments, the subject is a treatment naive subject. In some embodiments, the subject is treatment naive for treatment of an immune-related disorder or disease. In some embodiments, the subject has not undergone prior treatment with an anti-CD2 antibody or antigen-binding fragment thereof and / or an agent described herein.

[0056] Individuals selected to receive an organ transplant can follow these methods described herein with the goal of inducing a state of mixed chimerism in which recipient and donor hematopoietic cells coexist in the recipient, which, when achieved, reduces the need for long-term immunosuppressive therapy.

[0057] Subjects who have received or will receive organ and / or tissue transplants may be suitable for treatment with the methods provided herein. The methods described herein can be used for subjects who have received or will receive any organ and / or tissue transplant (e.g., lung, heart, kidney, liver, stomach, intestine, pancreas, skin, or spleen). Individuals whose organs have been damaged by means including injury, disease, or congenital defects may meet the criteria to receive an organ (e.g., liver or kidney) transplant and can be treated according to the methods described herein. Recipients treated according to the methods described herein may require an organ transplant for any reason. In general, patients suffering from end-stage organ disease who have a life expectancy that is predicted to be extended by organ transplantation beyond the life expectancy without organ transplantation may be considered for organ transplantation.

[0058] In certain embodiments, the recipient treated according to the methods described herein has received an organ transplant necessitated by the genetic disease. In certain embodiments, the organ transplant is a live donor organ transplant. In certain embodiments, the organ transplant is a deceased donor organ transplant. In some embodiments, the organ transplant can be an ABO (major human blood group system A, B, O) compatible transplant. In some embodiments, the organ transplant can be an ABO incompatible transplant. In some embodiments, the recipient treated according to the methods described herein can have an End-Stage Liver Disease (MELD) score of less than 30, less than 20, or less than 10. In some embodiments, the recipient treated according to the methods described herein can be seropositive for Epstein-Barr Virus (EBV). In some embodiments, the recipient has undergone a splenectomy prior to receiving the transplant. In some embodiments, the recipient has not undergone a splenectomy prior to receiving the transplant. In some embodiments, the subject is in need of or has undergone a liver transplant. Examples of indications for liver transplantation are described, for example, in EASL Clinical Practice Guidelines:Liver transplantation (J Hepatol. 2016Feb;64(2):433-485.doi:10.1016 / j.jhep.2015.10.006).

[0059] In some embodiments, the recipient may have a highly sensitized immune system. The development of a highly sensitized immune system is caused by previous exposure to foreign tissues and the development of antibodies against these tissues. Sources of this exposure may include blood transfusion, previous transplantation, or pregnancy. In a sensitized state, the immune system is hyper-aroused and produces antibodies that attack the transplanted organ. In certain embodiments, the recipients described herein may have a sensitized or non-sensitized immune system. Some recipients may be sensitized to rituximab. In such recipients, IdeS may be administered with rituximab. IdeS, an enzyme that cleaves the heavy chain of IgG, inhibits antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). In certain embodiments, IdeS is administered in combination with rituximab or anti-CD19 plasma cell-directed treatment. In certain embodiments, plasmapheresis may be used in combination with IdeS treatment and rituximab.

[0060] 5.2 Transplantation and Donors 5.2.1 Organ or tissue transplantation As used herein, a donor is an individual from whom an organ or tissue to be transplanted is taken. In some embodiments, the donor is the same species as the recipient, and the donor may be alive or dead. The donor may or may not be related to the recipient. As used herein, a recipient is an individual who receives or has received a transplanted organ or tissue. The recipient may or may not be related to the donor. The recipient may be HLA-matched or HLA-mismatched to the donor. In some embodiments, the transplanted organ or tissue is artificially created (e.g., not from a mammal), or created in vitro, or created outside the body. In some embodiments, the transplanted organ or tissue is from a different species (e.g., an organ or tissue from a different animal / mammal) than the recipient. In some embodiments, the transplanted organ or tissue is not from a human.

[0061] The organ that can be transplanted using the methods provided herein can be any solid organ. In some embodiments, the organ or tissue can be or can be derived from the kidney, heart, intestine, liver, lung, pancreas, or other organ or tissue that can be transplanted using the methods provided herein. In some embodiments, the organ or tissue can be a vascular composite allograft, including the hand, foot, other limb, face, or other body part that can be transplanted using the methods provided herein. In some embodiments, the transplanted organ or tissue can be a whole organ, a part of an organ, or cells derived from an organ.

[0062] 5.2.2 Bone marrow Hematopoietic stem cells can be derived from the bone marrow of a donor. In some embodiments, the bone marrow cells obtained from an organ or tissue donor can be HLA-matched to the recipient. In certain embodiments, the bone marrow cells obtained from an organ or tissue donor can be HLA-mismatched. In certain embodiments, bone marrow cell transplantation can be combined with organ or tissue transplantation, can occur after organ or tissue transplantation, or can occur before organ or tissue transplantation.

[0063] In certain embodiments, the desired outcome may be to induce a chimeric state in the recipient. By combining non-myeloablative conditioning with simultaneous transplantation of solid organs or tissues and infusion of hematopoietic cells from unprocessed donor bone marrow, the recipient may develop sustained mixed chimerism. As used herein, "chimerism" refers to a state in which both donor and recipient hematopoietic cells coexist. In certain embodiments, the recipient may be monitored to assess the presence of mixed chimerism. In certain embodiments, the recipient has or will have at least 1% circulating donor hematopoietic cells. In certain embodiments, the recipient will have about or at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% circulating donor hematopoietic cells. In certain embodiments, the recipient has or will have about 1-10%, 5-15%, 10-20%, 15-25%, 20-30%, 25-35%, 30-40%, 35-45%, 40-50%, 45-55%, 50-60%, 55-65%, 60-70%, 65-75%, 70-80%, 75-85%, 80-90%, or 85-95% circulating donor hematopoietic cells. In certain embodiments, this chimeric state may persist for a period of time, e.g., 5 days, 10 days, 15 days, 25 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, or longer than 6 months, for hematopoietic and / or immune cells. In certain embodiments, chimerism persists in the recipient for at least 6 months. In certain embodiments, the components of the bone marrow transplant may be altered as described herein to achieve and / or maintain mixed chimerism in the recipient as described herein.

[0064] 5.3 Preparative and postoperative regimens The conditioning regimen or use in the methods provided herein may include administration of one or more of the following therapies. In some embodiments, an anti-CD2 antibody or antigen-binding fragment thereof is provided to a subject. In some embodiments, an anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) is provided to a subject prior to transplantation or cell infusion (e.g., bone marrow cell infusion).

[0065] The conditioning regimen or use in the methods provided herein may include administration of one or more agents described herein (e.g., rituximab, cyclophosphamide, tocilizumab, corticosteroids, tacrolimus, MMF, antiproliferative agents, steroids, sirolimus, polyclonal rabbit antithymocyte globulin (rATG), fludarabine, B or plasma cell depleting antibodies, immunosuppressants, chemotherapeutic agents, antiproliferative agents, anti-neoplastic agents, anti-IL6R antibodies, and / or irradiation). In some embodiments, one or more agents described herein are administered with, prior to, or after thymic (or thymus) irradiation, transplantation, and / or cell (e.g., bone marrow) infusion. In some embodiments, one or more agents are administered prophylactically (e.g., tocilizumab).

[0066] In some embodiments, an agent or agents are administered to the subject prior to transplant. In some embodiments, the agent or agents are or include an anti-CD2 antibody or antigen-binding fragment thereof and / or a non-myeloablative agent. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered in combination with the non-myeloablative agent. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered before, on the same day, or after the non-myeloablative agent. In some embodiments, the non-myeloablative agent comprises one or more of a B cell depleting antibody, rituximab, fludarabine, cyclophosphamide, a chemotherapy drug, and / or irradiation (e.g., thymic irradiation). In some embodiments, the non-myeloablative agent comprises fludarabine and cyclophosphamide. In some embodiments, the non-myeloablative agent comprises fludarabine (or an equivalent / interchangeable agent or agent in the same class as fludarabine). In some embodiments, the non-myeloablative agent is administered at a dose of about 10 mg / m 2 In some embodiments, the non-myeloablative agent comprises cyclophosphamide (or an equivalent / interchangeable agent or an agent in the same class as cyclophosphamide). In some embodiments, the non-myeloablative agent comprises about 22.5 mg / kg cyclophosphamide. In some embodiments, the non-myeloablative agent comprises about 60 mg / kg cyclophosphamide. In some embodiments, the non-myeloablative agent comprises a B cell depleting antibody (e.g., rituximab (e.g., about 375 mg / m 2 In some embodiments, the non-myeloablative agent comprises low dose fludarabine and cyclophosphamide. In some embodiments, the non-myeloablative agent comprises low dose fludarabine and cyclophosphamide. 2 5 mg / kg of fludarabine and about 22.5 mg / kg of cyclophosphamide. In some embodiments, the non-myeloablative agent comprises cell infusion (e.g., bone marrow cell infusion). In some embodiments, the non-myeloablative agent comprises thymic irradiation. In some embodiments, the non-myeloablative agent comprises rituximab, cyclophosphamide, and / or thymic irradiation.

[0067] In some embodiments, the agent or agents are administered to the subject prior to cell infusion (e.g., bone marrow cell infusion). In some embodiments, the agent or agents are administered to the subject after transplant. In some embodiments, the agent or agents are administered to the subject after cell infusion (e.g., bone marrow cell infusion). In some embodiments, the agent or agents are administered to the subject on the same day as the transplant. In some embodiments, the agent or agents are administered to the subject on the same day as the cell infusion (e.g., bone marrow cell infusion). In some embodiments, the agent or agents are administered to the subject about or at least about 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 day prior to transplant. In some embodiments, the agent or agents are administered to the subject about or at least about 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject about or at least about 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 days after transplantation. In some embodiments, the agent or agents are administered to the subject about or at least about 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 days after cell infusion. In some embodiments, the agent or agents are administered to the subject 9 days prior to transplantation. In some embodiments, the agent or agents are administered to the subject 9 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 6 days prior to transplantation. In some embodiments, the agent or agents are administered to the subject 6 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 5 days prior to transplantation. In some embodiments, the agent or agents are administered to the subject 5 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 4 days prior to transplantation.In some embodiments, the agent or agents are administered to the subject 4 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 3 days prior to transplantation. In some embodiments, the agent or agents are administered to the subject 3 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 2 days prior to transplantation. In some embodiments, the agent or agents are administered to the subject 2 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 1 day prior to transplantation. In some embodiments, the agent or agents are administered to the subject 1 day prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 1 day after transplantation. In some embodiments, the agent or agents are administered to the subject 1 day after cell infusion. In some embodiments, the agent or agents are administered to the subject at least once, at least twice, at least three times, at least four times, at least five times, at least six times, at least seven times, at least eight times, at least nine times, at least ten times, or more than ten times prior to transplantation. In some embodiments, the agent or agents are administered to the subject at least once, at least two times, at least three times, at least four times, at least five times, at least six times, at least seven times, at least eight times, at least nine times, at least ten times, or more than ten times prior to cell transfer infusion. In some embodiments, the agent or agents are administered to the subject at least one day, at least two days, at least three days, at least four days, at least five days, at least six days, at least seven days, at least eight days, at least nine days, at least ten days, or more than ten days prior to transplantation. In some embodiments, the agent or agents are administered to the subject at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, or more than at least 10 days prior to cell infusion.In some embodiments, the agent or agents are administered to the subject at least once, at least twice, at least three times, at least four times, at least five times, at least six times, at least seven times, at least eight times, at least nine times, at least ten times, or more than ten times after transplantation. In some embodiments, the agent or agents are administered to the subject at least once, at least two times, at least three times, at least four times, at least five times, at least six times, at least seven times, at least eight times, at least nine times, at least ten times, or more than ten times after cell transfer infusion. In some embodiments, the agent or agents are administered to the subject at least one day, at least two days, at least three days, at least four days, at least five days, at least six days, at least seven days, at least eight days, at least nine days, at least ten days, or more than ten days after transplantation. In some embodiments, the agent or agents are administered to the subject at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, or at least more than 10 days after cell injection.

[0068] In some embodiments, the agent or agents (e.g., an anti-CD2 antibody or antigen-binding fragment thereof, or agent or non-myeloablative agent) are administered to the recipient about, at least about, or up to about once (or one day), twice (or on two different days), three times (or on three different days), four times (or on four different days), five times (or on five different days), six times (or on six different days), seven times (or on seven different days), eight times (or on eight different days), nine times (or on nine different days), ten times (or on ten different days), or more than ten times (or on ten different days) prior to transplantation and / or cell infusion. In some embodiments, the agent or agents (e.g., an anti-CD2 antibody or antigen-binding fragment thereof, or agent or non-myeloablative agent) are administered to the recipient about, at least about, or up to about once (or one day), twice (or on two different days), three times (or on three different days), four times (or on four different days), five times (or on five different days), six times (or on six different days), seven times (or on seven different days), eight times (or on eight different days), nine times (or on nine different days), ten times (or on ten different days), or more than ten times (or on more than ten different days) following transplantation and / or cell infusion.

[0069] In some embodiments, the agent or agents are administered to the subject for consecutive hours / days prior to transplantation. In some embodiments, the agent or agents are administered to the subject for consecutive hours / days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject for consecutive hours / days after transplantation. In some embodiments, the agent or agents are administered to the subject for consecutive hours / days after cell infusion. In some embodiments, the agent or agents are administered to the subject for about, at least about, or up to about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, 18 months, 20 months, 21 months, 22 months, 23 months, 24 months, or more than 24 months after transplantation. In some embodiments, the agent or agents are administered to the subject for about or up to about 12 months. In some embodiments, the agent or agents are administered to the subject for about or up to about 18 months. In some embodiments, the agent or agents are administered to the subject for about, at least about, or up to about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after cell infusion.

[0070] In some embodiments, the agent or agents are administered to the subject 9 days and / or 2 days prior to transplantation. In some embodiments, the agent or agents are administered to the subject 9 days and / or 2 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 6 days, 5 days, 4 days and / or 3 days prior to transplantation. In some embodiments, the agent or agents are administered to the subject 6 days, 5 days, 4 days and / or 3 days prior to cell infusion. In some embodiments, the agent or agents are administered to the subject 1 day prior to transplantation, the same day as transplantation, and / or the day after transplantation. In some embodiments, the agent or agents are administered to the subject 1 day prior to cell infusion, the same day as cell infusion, and / or the day after cell infusion. In some embodiments, the agent or agents are administered to the subject 6 days prior to transplantation, 1 day prior to transplantation, the same day as transplantation, the day after transplantation, and / or 6 days after transplantation. In some embodiments, the agent or agents are administered to the subject 6 days prior to cell infusion, 1 day prior to cell infusion, the same day as cell infusion, 1 day after cell infusion, and / or 6 days after cell infusion. In some embodiments, the agent or agents are administered to the subject the same day as transplantation. In some embodiments, the agent or agents are administered to the subject the same day as cell infusion. In some embodiments, the agent or agents are administered to the subject 1 day after transplantation. In some embodiments, the agent or agents are administered to the subject 1 day after cell infusion.

[0071] In some embodiments, the agent or agents are B cell depleting antibodies (e.g., 375 mg / m 2 In some embodiments, the agent or agents are or include a B cell depleting antibody (e.g., 375 mg / m rituximab) and are administered to the subject (e.g., day -9 and / or day -2 prior to transplant / cell infusion). 2In some embodiments, the agent or agents are or include an anti-neoplastic agent (e.g., 10 mg / m rituximab) and are administered to the subject (e.g., day -9 and / or day -2 prior to transplantation / cell infusion and / or 5 days after transplantation / cell infusion and / or 12 days after transplantation / cell infusion). In some embodiments, the agent or agents are an anti-neoplastic agent (e.g., 10 mg / m rituximab) and are administered to the subject (e.g., day -9 and / or day -2 prior to transplantation / cell infusion and / or 5 days after transplantation / cell infusion and / or 12 days after transplantation / cell infusion). 2In some embodiments, the agent or agents is or comprises an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg siplizumab) and is administered to the subject (e.g., on day -6, -5, -4, and / or -3 prior to transplantation / cell infusion). In some embodiments, the agent or agents is or comprises an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg siplizumab) and is administered to the subject (e.g., on day -1 prior to transplantation / cell infusion, on day of transplantation / cell infusion (day 0), and / or on day after transplantation / cell infusion (day 1)). In some embodiments, the agent or agents is or comprises an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg siplizumab) and is administered to the subject (e.g., 6 days prior to transplantation / cell infusion, on day -1 prior to transplantation / cell infusion, on day of transplantation / cell infusion (day 0), and / or on day after transplantation / cell infusion (day 1)). In some embodiments, the agent or agents is or comprises an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg siplizumab) and is administered to the subject (e.g., 6 days prior to transplantation / cell infusion, the day prior to transplantation / cell infusion (day -1), the day of transplantation / cell infusion (day 0), 1 day after transplantation / cell infusion (day 1) and / or 6 days after transplantation (day 6)). In some embodiments, the agent or agents is or comprises a chemotherapeutic agent or an immunosuppressant (e.g., cyclophosphamide, e.g., 22.5 mg / kg) and is administered to the subject (e.g., day -5 and / or day -4 prior to transplantation). In some embodiments, irradiation (e.g., thymic irradiation, 7 Gy) is administered to the subject prior to the day of transplantation. In some embodiments, the agent or agents is or comprises an immunosuppressant (e.g., tacrolimus, e.g., 8-10 ng / mL) and is administered to the subject (e.g., the day of transplantation and / or about 1 month). In some embodiments, the agent or agents is or includes an immunosuppressant (e.g., tacrolimus, e.g., 4-11 ng / mL) and is administered to the subject (e.g., on the day of transplant and / or for about 9-12 months).In some embodiments, the agent or agents are or include an anti-proliferative agent (e.g., MMF, e.g., 1 g / day) and are administered to the subject (e.g., on the day of transplant and / or for about 1-2 months). In some embodiments, the agent or agents are or include a chemotherapeutic agent or an immunosuppressant (e.g., a corticosteroid) and are administered to the subject (e.g., on the day of transplant and / or for 6 months). In some embodiments, the agent or agents are or include a chemotherapeutic agent or an immunosuppressant (e.g., a corticosteroid) and are administered to the subject (e.g., on the day of transplant and / or for 20 days). In some embodiments, the agent or agents are or include an immunosuppressant (e.g., sirolimus, initial trough 5-8 ng / mL) and are administered to the subject (e.g., 1 month after the day of transplant and / or for about 1-12 months). In some embodiments, the agent or agents is or comprises an anti-IL6R antibody (e.g., tocilizumab) and is administered to the subject (e.g., 7 days after transplantation or cell infusion and / or 14 days after transplantation or cell infusion if CTS occurs).

[0072] 5.3.1 Implant Treatment In certain embodiments, the conditioning regimen may include direct injection of an anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) into the organ. In certain embodiments, the graft may be directly injected with the anti-CD2 antibody or antigen-binding fragment thereof. This injection may be administered at one site on the graft or may be administered at multiple sites on the graft. In certain embodiments, the graft may be incubated in a bath containing the anti-CD2 antibody or antigen-binding fragment thereof. This incubation may occur during transportation to surgery or at the surgery site. In some embodiments, the incubation is continued for a period of time to allow sufficient uptake of the anti-CD2 antibody or antigen-binding fragment thereof into the graft. The incubation may be for about, at least about, or up to about 15 minutes, 30 minutes, 45 minutes, 1 hour, 1.25 hours, 1.5 hours, 1.75 hours, 2 hours, 2.25 hours, 2.5 hours, 2.75 hours, 3 hours, 3.25 hours, 3.5 hours, 3.75 hours, 4 hours, 4.25 hours, 4.5 hours, 4.75 hours, 5 hours, 5.25 hours, 5.5 hours, 5.75 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, It may be performed for 9 hours, 9.5 hours, 10 hours, 10.5 hours, 11 hours, 11.5 hours, 12 hours, 12.5 hours, 13 hours, 13.5 hours, 14 hours, 14.5 hours, 15 hours, 15.5 hours, 16 hours, 16.5 hours, 17 hours, 17.5 hours, 18 hours, 18.5 hours, 19 hours, 19.5 hours, 20 hours, 20.5 hours, 21 hours, 21.5 hours, 22 hours, 22.5 hours, 23 hours, 23.5 hours, or 24 hours. In certain embodiments, the dose of the anti-CD2 antibody or antigen-binding fragment thereof for injection is about, at least about, or up to about 0.01 mg / kg, 0.05 mg / kg, 0.1 mg / kg, 0.5 mg / kg, 0.6 mg / kg, 1 mg / kg, 5 mg / kg, 10 mg / kg, or 50 mg / kg.

[0073] In certain embodiments, the organ or tissue may be incubated in a bath containing an anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab). In some embodiments, the organ or tissue is maintained in a bath containing an anti-CD2 antibody or antigen-binding fragment thereof from the time of removal of the organ or tissue from the donor until transplantation into the recipient. In certain embodiments, the concentration of the anti-CD2 antibody or antigen-binding fragment thereof in the organ or tissue bath is about or at least about 0.01 mg / liter, about or at least about 0.05 mg / liter, about or at least about 0.1 mg / liter, about or at least about 0.5 mg / liter, about or at least about 0.6 mg / liter, about or at least about 1 mg / liter, about or at least about 5 mg / liter, about or at least about 10 mg / liter, or about or at least about 50 mg / liter.

[0074] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof may be administered to the organ or tissue via the circulatory system. In some embodiments, a catheter may be inserted into an adjacent blood vessel and attached to a pump. The anti-CD2 antibody or antigen-binding fragment thereof may be pumped through the blood vessel and delivered to the organ. In certain embodiments, the transplant procedure may be modified as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0075] 5.3.2 Anti-CD2 Antibodies or Antigen-Binding Fragments Thereof In certain embodiments, the methods described herein include administering an anti-CD2 antibody or antigen-binding fragment thereof to a subject (e.g., a recipient). As defined herein, an antibody refers to an immunoglobulin, including IgG, IgM, IgE, IgA, and IgD. The antibodies described herein can be monoclonal or polyclonal. In some embodiments, the antibodies can be chimeric antibodies. In some embodiments, the antibodies can be humanized antibodies. In certain embodiments, the antibodies are recombinant antibodies. In certain embodiments, the antibodies are humanized antibodies. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein are IgG. In certain embodiments, the IgG can be IgG1, IgG2, IgG3, or IgG4. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein are IgG1, IgG2, or IgG4. As described herein, the anti-CD2 antibodies or antigen-binding fragments thereof described herein can be antigen-binding fragments. In certain embodiments, the antigen-binding fragment may be or comprise a Fab, F(ab')2, scFv (VH fused to VL), or sdAb.

[0076] In some embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods and compositions of the invention has the CDR sequences of rat anti-CD2 monoclonal antibody BTI-322. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof can be a humanized IgG1 version of BTI-322 (siplizumab; MEDI-507). In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is an Fc-silenced anti-CD2 antibody or antigen-binding fragment thereof. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is BTI-322 or an antigen-binding fragment thereof. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is CB.219 or an antigen-binding fragment thereof. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is LO-CD2b or an antigen-binding fragment thereof. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is siplizumab or an antigen-binding fragment thereof. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is anti-CD2 antibody 1 or an antigen-binding fragment thereof. In some embodiments, the anti-CD2 antibody 1 is siplizumab or an antigen-binding fragment thereof. In some embodiments, the methods described herein include administering at least one, at least two, at least three, or more than at least three anti-CD2 antibodies or antigen-binding fragments thereof. In some embodiments, the methods described herein include administering one or more anti-CD2 antibodies or antigen-binding fragments thereof. In certain embodiments, the methods described herein include administering to the subject an anti-CD2 antibody or antigen-binding fragment thereof in combination with another agent. In certain embodiments, the methods described herein include administering to the subject an anti-CD2 antibody or antigen-binding fragment thereof before, simultaneously with, and / or after the other agent.

[0077] The antibodies described herein may consist of two heavy chains and two light chains linked by disulfide bonds. Each heavy chain may comprise a variable region (VH) and a constant region. Each light chain may comprise a variable region (VL) and a constant region. The variable regions of both the heavy and light chains determine the binding of the antibody to the antigen. The complementarity determining regions are the variable loops on the variable regions of the heavy and light chains. There are three CDRs on each heavy chain and three CDRs on each light chain. In certain embodiments, the antibodies described herein bind to CD2.

[0078] In certain embodiments, administration of the anti-CD2 antibody or antigen-binding fragment thereof described herein does not result in target cell depletion.In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein exhibits immunomodulatory activity.In certain embodiments, the ability of the anti-CD2 antibody or antigen-binding fragment thereof described herein to inhibit target cell depletion while retaining immunomodulatory activity is achieved by removing the glycosylation of the Fc region.

[0079] In some embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein specifically bind to CD2 (also called T11, SRBC (sheep red blood cell receptor) and LFA-2). In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein bind to human CD2 (GenBank Accession No. NM_001328609.1 (isoform 1); NM_001767.5 (isoform 2)). In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein may competitively bind to siplizumab (Medlmmune Inc.; International Publication No. WO 02 / 098370). Siplizumab (MEDI-507) is a humanized version of the CD2-specific rat antibody BTI-322 (Medlmmune Inc.; International Publication No. WO 02 / 098370). Siplizumab is an IgG1 kappa class monoclonal antibody that binds to CD2 found on human T cells and human NK cells. Siplizumab is composed of two heavy chains (approximately 50 kDa) and two light chains (approximately 25 kDa).

[0080] As defined herein, an epitope is a region of an antigen to which an antibody or antigen-binding fragment binds. In some embodiments, the epitope is linear. In other embodiments, the epitope may be conformational. In some embodiments, the epitope may be formed by contiguous amino acids. In other embodiments, the epitope may be formed by non-contiguous amino acids. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein bind to an epitope on CD2. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein bind to the same epitope of CD2 as siplizumab. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein can competitively bind to siplizumab in a suitable in vitro competitive binding assay, such as those detailed in Clark et al., J Exp Med. 1988 Jun 1; 167(6): 1861-72. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein have the same IC as siplizumab. 50 In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein have an IC value lower than that of siplizumab. 50 In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein have a higher IC value than siplizumab. 50 In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein have an IC of about, at least about, or up to about 0.5 nM, 0.6 nM, 0.7 nM, 0.8 nM, 0.9 nM, 1.0 nM, 1.1 nM, 1.2 nM, 1.3 nM, 1.4 nM, 1.5 nM, 0.5 nM to 0.8 nM, 0.6 nM to 0.9 nM, 0.7 nM to 1.0 nM, 0.8 nM to 1.1 nM, 0.9 nM to 1.2 nM, 1.0 nM to 1.3 nM, 1.1 nM to 1.4 nM, or 1.2 nM to 1.5 nM. 50It has a value.

[0081] In certain embodiments, the sequence of the VH region of the anti-CD2 antibodies or antigen-binding fragments thereof described herein is 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 1. In certain embodiments, the sequence of the VL region of the anti-CD2 antibodies or antigen-binding fragments thereof described herein is 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 2. In certain embodiments, the sequence of the VH CDR1 of the anti-CD2 antibodies or antigen-binding fragments thereof described herein can be SEQ ID NO: 3. In certain embodiments, the sequence of the VH CDR2 of the anti-CD2 antibodies or antigen-binding fragments thereof described herein can be SEQ ID NO: 4. In certain embodiments, the sequence of the VH CDR3 of the anti-CD2 antibodies or antigen-binding fragments thereof described herein can be SEQ ID NO: 5. In certain embodiments, the sequence of the VL CDR1 of an anti-CD2 antibody or antigen-binding fragment thereof described herein may be SEQ ID NO: 6. In certain embodiments, the sequence of the VL CDR2 of an anti-CD2 antibody or antigen-binding fragment thereof described herein may be SEQ ID NO: 7. In certain embodiments, the sequence of the VL CDR3 of an anti-CD2 antibody or antigen-binding fragment thereof described herein may be SEQ ID NO: 8. These sequences are shown in Table 1.

[0082] In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods provided herein has a heavy chain variable region comprising the VH CDRs of SEQ ID NOs: 3-5, respectively, and the VL of SEQ ID NO: 2. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods provided herein has a heavy chain variable region comprising the VL CDRs of SEQ ID NOs: 6-8, respectively, and the VH of SEQ ID NO: 1.

[0083] In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods provided herein has a heavy chain variable region CDR1 of SEQ ID NO: 3; a heavy chain variable region CDR2 of SEQ ID NO: 4; a heavy chain variable region CDR3 of SEQ ID NO: 5; a light chain variable region CDR1 of SEQ ID NO: 6; a light chain variable region CDR2 of SEQ ID NO: 7; and a light chain variable region CDR3 of SEQ ID NO: 8. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods provided herein comprises a heavy chain variable region CDR1 comprising a sequence that is at least about or about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO:3; a heavy chain variable region CDR2 comprising a sequence that is at least about or about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO:4; a heavy chain variable region CDR3 comprising a sequence that is at least about or about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO:5; a heavy chain variable region CDR3 comprising a sequence that is at least about or about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO:6; a light chain variable region CDR1 comprising a sequence that is at least about or about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO:7; and / or a light chain variable region CDR3 comprising a sequence that is at least about or about 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to SEQ ID NO:8.

[0084] In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods provided herein comprises a heavy chain variable region CDR1 comprising a sequence having about or at least about one amino acid substitution, about or at least about two amino acid substitutions, about or at least about three amino acid substitutions, about or at least about four amino acid substitutions, or more than about four amino acid substitutions with SEQ ID NO:3; a heavy chain variable region CDR2 comprising a sequence having about or at least about one amino acid substitution, about or at least about two amino acid substitutions, about or at least about three amino acid substitutions, about or at least about four amino acid substitutions, or more than about four amino acid substitutions with SEQ ID NO:4; a heavy chain variable region CDR3 comprising a sequence having about or at least about one amino acid substitution, about or at least about two amino acid substitutions, about or at least about three amino acid substitutions, about or at least about four amino acid substitutions, or more than about four amino acid substitutions with SEQ ID NO:5; a heavy chain variable region CDR3 comprising a sequence having about or at least about one amino acid substitution, about or at least about two amino acid substitutions, about or at least about three amino acid substitutions, about or at least about four amino acid substitutions, or more than at least about four amino acid substitutions relative to SEQ ID NO:6; a light chain variable region CDR2 comprising a sequence having about or at least about one amino acid substitution, about or at least about two amino acid substitutions, about or at least about three amino acid substitutions, about or at least about four amino acid substitutions, or more than at least about four amino acid substitutions relative to SEQ ID NO:7; and / or a light chain variable region CDR3 comprising a sequence having about or at least about one amino acid substitution, about or at least about two amino acid substitutions, about or at least about three amino acid substitutions, about or at least about four amino acid substitutions, or more than at least about four amino acid substitutions relative to SEQ ID NO:8.

[0085] In some embodiments, the amino acid substitution is a conservative substitution. Illustrative examples of conservative amino acid exchanges are amino acid substitutions that maintain the structural and / or functional properties of the amino acid side chain, such as an aromatic amino acid being replaced with another aromatic amino acid, an acidic amino acid being replaced with another acidic amino acid, a basic amino acid being replaced with another basic amino acid, and an aliphatic amino acid being replaced with another aliphatic amino acid. In some embodiments, a conservative amino acid substitution is one in which an amino acid residue is replaced with an amino acid residue having a side chain with a similar charge. As described above, families of amino acid residues having side chains with similar charges have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g., glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). In contrast, examples of non-conservative amino acid exchanges are amino acid substitutions that do not maintain the structural and / or functional properties of the amino acid side chain, e.g., an aromatic amino acid is replaced with a basic, acidic, or aliphatic amino acid, an acidic amino acid is replaced with an aromatic, basic, or aliphatic amino acid, a basic amino acid is replaced with an acidic, aromatic, or aliphatic amino acid, and an aliphatic amino acid is replaced with an aromatic, acidic, or basic amino acid.

[0086] In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods and compositions of the invention comprises heavy chain CDR1, 2, or 3 of BTI-322 or siplizumab. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods and compositions of the invention comprises light chain CDR1, 2, or 3 of BTI-322 or siplizumab. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods and compositions of the invention comprises one, two, three, four, five, or all six CDRs of BTI-322 or siplizumab. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof for use with the methods described herein comprises one, two, three, four, five, or all six CDRs described in this disclosure (e.g., Table 1 and / or Table 15). In certain embodiments, one, two, three, four, five, and / or all six CDRs of BTI-322 or siplizumab have one, two, three, four, five, six, seven, eight, nine, or ten amino acid substitutions. In certain more particular embodiments, such amino acid substitutions are conservative amino acid substitutions. [Table 1]

[0087] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein has the same six CDR sequences as siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein can share five of the six CDR sequences of siplizumab. In certain embodiments, one of the CDRs of the anti-CD2 antibody or antigen-binding fragment thereof described herein is different from the corresponding CDR of siplizumab, and the CDR sequence differs by only one amino acid. In certain embodiments, the difference between the CDR sequence of the anti-CD2 antibody or antigen-binding fragment thereof described herein and the corresponding CDR of siplizumab is a conservative amino acid substitution. For example, the anti-CD2 antibody or antigen-binding fragment thereof can have one, two, three, four, five, or six conservative amino acid substitutions for the set of six CDRs of siplizumab, or for the set of three CDRs in the heavy chain of siplizumab, or for the set of three CDRs in the light chain of siplizumab.

[0088] In certain embodiments, the VL CDR1, VL CDR2, or VL CDR3 of the anti-CD2 antibody or antigen-binding fragment thereof described herein is a different CDR from its siplizumab counterpart. In another embodiment, the VH CDR1, VH CDR2, or VH CDR3 of the anti-CD2 antibody or antigen-binding fragment thereof described herein is a different CDR from its siplizumab counterpart. In certain embodiments, the different CDR of the anti-CD2 antibody or antigen-binding fragment thereof described herein is longer than the sequence of its siplizumab counterpart. In another embodiment, the different CDR of the anti-CD2 antibody or antigen-binding fragment thereof described herein is shorter than the sequence of its siplizumab counterpart.

[0089] In certain embodiments, the sequence of the heavy chain constant region (CH) of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 9. In certain embodiments, the sequence of the heavy chain constant region of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 10. In certain embodiments, the sequence of the heavy chain constant region of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 11. In certain embodiments, the sequence of the heavy chain constant region of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 12. In certain embodiments, the sequence of the heavy chain constant region of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 13. In certain embodiments, the sequence of the light chain constant region (CL) of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 14. In certain embodiments, the sequence of the light chain constant region of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO:15.

[0090] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein may be directed against three regions of human CD2 known in the art as T111, T112, and T113 (Peterson, A., Seed, B., 1987. Nature 329, 842-846; Branco et al., 1999. Transplantation 68, 1588-1596; Arulanandam, AR, et al., 1993. Proc. Natl. Acad. Sci. USA 90, 11613-11617; Damschroder et al., 2004. Molecular Immunology 41, 985-1000). Three residues in the adhesive domain of human CD2 that are important for binding to siplizumab are N18, K55, and T5 (Damschroder et al., 2004. Molecular Immunology 41, 985-1000). In certain embodiments, residues N18, K55, and T59 in the extracellular CD2 domain are important residues in the binding affinity of the anti-CD2 antibodies or antigen-binding fragments thereof described herein to human CD2. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein bind to the same epitope as siplizumab. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein bind to human CD2 competitively with siplizumab.

[0091] In certain embodiments, the DNA sequence of the anti-CD2 antibody or antigen-binding fragment thereof may be altered to optimize product yield during manufacturing. Since the amino acid sequence produced may be the same as that set forth in Table 1, sequence optimization may increase product yield without affecting product quality secretion of the molecule during production. The optimized DNA sequences of the anti-CD2 antibody or antigen-binding fragment thereof heavy and light chains are shown in Table 2. [Table 2] TIFF2024534926000004.tif154165

[0092] In certain embodiments, the heavy chain sequence of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 16. In certain embodiments, the light chain constant region sequence of an anti-CD2 antibody or antigen-binding fragment thereof described herein is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 17.

[0093] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof interferes with the CD58 / CD2 signaling cascade. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof blocks CD58. An example of a compound that inhibits the CD58 / CD2 pathway is alefacept.

[0094] In certain embodiments, depleted forms of siplizumab may be used for the treatment of autoimmune diseases (e.g., arising as a result of organ or tissue transplantation) or in subjects who have or will receive an organ or tissue transplant.

[0095] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein have no or reduced antibody-dependent cellular cytotoxicity ("ADCC"). In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof can be generated to exhibit reduced or absent ADCC using methods including, but not limited to, Fc silencing, subclass switching, deglycosylation, and other mutations or modifications of the Fc region. These methods are described, for example, in U.S. Provisional Application No. 63 / 135,381, which is incorporated herein by reference in its entirety for non-limiting examples of anti-CD2 antibodies or antigen-binding fragments thereof that may be used in the methods described herein.

[0096] ADCC activity can be determined by any commercially available kit (see, for example, Promega ADCC Reporter Bioassay, Core Kit (Cat.#G7010, G7018)) or any suitable assay. Such assays can include, but are not limited to, flow cytometry-based assays, fluorometric assays, or bioluminescence reporter assays.

[0097] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein exhibit up to 90% of the ADCC activity of siplizumab in an in vitro assay. An example of such an assay is described in the method of Golay et al., Haematologica. January 2003; 88: 1002-1012. Specifically, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein exhibit up to 0%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or up to 90% of the ADCC activity compared to siplizumab.

[0098] In certain embodiments, in vivo administration of an anti-CD2 antibody or antigen-binding fragment thereof provided herein exhibits up to 90% ADCC activity compared to in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting. Specifically, in vivo administration of a CD2 binding molecule (or an anti-CD2 antibody or antigen-binding fragment thereof) provided herein exhibits up to 0%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or up to 90% ADCC activity as in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting.

[0099] Immunomodulatory activities exhibited by the anti-CD2 antibodies or antigen-binding fragments thereof described herein include, but are not limited to, inhibition of CD4+ / CD25+ T cell activation and proliferation, increased FOXP3 +The immunomodulatory activity may include the percentage of regulatory T cells, and suppression of CD69+ NK cells. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein exhibit the same immunomodulatory activity (e.g., the same type and level) as siplizumab. Determination of immunomodulatory activity may be accomplished by any suitable method known in the art. These methods include, but are not limited to, cell proliferation assays, T cell activation functional assays, ELISPOT assays, intracellular staining, cytokine capture, tetramer staining, spectral typing assays, and biosensor assays. As an example, T cell activation may be determined by any commercially available assay kit (see, for example, Promega T Cell Activation Bioassay (NFAT or IL-2) (Cat.#J1621 or J1651)), or any suitable assay, which simply involves coating an assay plate with anti-CD3 antibody, adding human PBMCs or mouse peripheral target cells, adding anti-CD28 to the cells, and quantifying proliferation.

[0100] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein can inhibit activation and proliferation of CD4+ / CD25+ T cells in in vitro assays to levels of about or at least about 50% of the levels achieved by siplizumab. Examples of such assays are described in the methods of Ng et al., Blood 2001;98:2736-2744. Specifically, the anti-CD2 antibodies or antigen-binding fragments thereof described herein can inhibit activation and proliferation of CD4+ / CD25+ T cells in vitro to levels of about or at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the levels achieved by siplizumab.

[0101] In certain embodiments, in vivo administration of an anti-CD2 antibody or antigen-binding fragment thereof provided herein exhibits about or at least about 50% levels of CD4+ / CD25+ T cell activation / proliferation compared to in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting. Specifically, in vivo administration of an anti-CD2 antibody or antigen-binding fragment thereof provided herein exhibits about or at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% levels of CD4+ / CD25+ T cell activation / proliferation compared to in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting.

[0102] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein inhibit FOXP3 as compared to siplizumab. + In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein can increase the amount of regulatory T cells to a level of about or at least about 50% of the amount achieved by siplizumab in an in vitro assay. + It is possible to increase the amount of regulatory T cells. An example of such an assay is described in the method of Sambucci et al., Scientific Reports. 8:3674 (2018). Specifically, the anti-CD2 antibodies or antigen-binding fragments thereof described herein can enhance the FOXP3 T cell proliferation and proliferation achieved by siplizumab. + FOXP3 in vitro to a level of about or at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the amount of regulatory T cells. + The amount of regulatory T cells can be increased.

[0103] In certain embodiments, in vivo administration of an anti-CD2 antibody or antigen-binding fragment thereof provided herein reduces FOXP3 levels by about, or at least about, 50% compared to in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting. + Indicating regulatory T cells. Specifically, in vivo administration of the anti-CD2 antibodies or antigen-binding fragments thereof provided herein induces about or at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% levels of FOXP3 compared to in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting. + This shows regulatory T cells.

[0104] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein can inhibit the expression of CD69+ NK cells compared to siplizumab. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein exhibit about or up to about 50% expression of CD69+ NK cells compared to siplizumab in an in vitro assay. Examples of such assays are described in the methods of Thum et al., Human Reproduction. 19:10, pp. 2395-2400, 2004. Specifically, the anti-CD2 antibodies or antigen-binding fragments thereof described herein exhibit up to 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or up to 90% expression of CD69+ NK cells in vitro compared to siplizumab.

[0105] In certain embodiments, in vivo administration of an anti-CD2 antibody or antigen-binding fragment thereof provided herein exhibits about or up to about 50% expression of CD69+ NK cells compared to in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting. Specifically, in certain embodiments, in vivo administration of an anti-CD2 antibody or antigen-binding fragment thereof provided herein exhibits about or up to about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or up to about 90% expression of CD69+ NK cells compared to in vivo administration of siplizumab in a humanized mouse model or human subject in a clinical setting.

[0106] In some embodiments, administration of an anti-CD2 antibody or antigen-binding fragment thereof described herein completely eliminates ADCC activity in the recipient while retaining immunomodulatory activity. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein is an IgG1 antibody and has modifications in the Fc region. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein is an IgG2 antibody and has modifications in the Fc region. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein is an IgG3 antibody and has modifications in the Fc region. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein is an IgG4 antibody and has modifications in the Fc region. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein comprise at least one mutation (e.g., about or at least 1, about or at least 2, about or at least 3, about or at least 4, about or at least 5, about or at least 6, about or at least 7, about or at least 8, about or at least 9, about or at least 10, or more than about 10 mutations) relative to siplizumab. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein comprise about one mutation, about two mutations, about three mutations, about four mutations, about five mutations, about six mutations, about seven mutations, about eight mutations, about nine mutations, about ten mutations, or more than about 10 mutations relative to siplizumab (e.g., mutations in the Fc region of siplizumab). In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein comprise siplizumab CDRs and at least one mutation (e.g., about or at least 1, about or at least 2, about or at least 3, about or at least 4, about or at least 5, about or at least 6, about or at least 7, about or at least 8, about or at least 9, about or at least 10, or more than about 10 mutations) in the IgG1 heavy chain.In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein comprise siplizumab CDRs and at least one mutation (e.g., about or at least 1, about or at least 2, about or at least 3, about or at least 4, about or at least 5, about or at least 6, about or at least 7, about or at least 8, about or at least 9, about or at least 10, or more than about 10 mutations) in the IgG2 heavy chain. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein comprise siplizumab CDRs and at least one mutation (e.g., about or at least 1, about or at least 2, about or at least 3, about or at least 4, about or at least 5, about or at least 6, about or at least 7, about or at least 8, about or at least 9, about or at least 10, or more than about 10 mutations) in the IgG3 heavy chain. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein comprises a siplizumab CDR and at least one mutation (e.g., about or at least 1, about or at least 2, about or at least 3, about or at least 4, about or at least 5, about or at least 6, about or at least 7, about or at least 8, about or at least 9, about or at least 10, or more than about 10 mutations) in the IgG4 heavy chain. The mutations can comprise at least one change in the amino acid sequence of the anti-CD2 antibody or antigen-binding fragment thereof compared to the wild-type counterpart, which change results in reduced or eliminated binding of the Fc region to its cognate receptor. In some embodiments, the mutations are one or more mutations, including mutations at amino acid positions L234, L235, P329, V234, G237, P238, H268, V309, A330, P331, and / or S228 (e.g., based on Edelman (EU) numbering). In some embodiments, the mutation is one or more mutations, including mutations at amino acid positions L234 and / or L235.In some embodiments, the mutations are one or more mutations and include mutations at amino acid positions L234, L235, and / or P329. In some embodiments, the mutations are one or more mutations and include mutations at amino acid positions V234, G237, P238, H268, V309, A330, and / or P331. In some embodiments, the mutations are one or more mutations and include mutations at amino acid positions S228. In some embodiments, the mutations are one or more mutations and include mutations at amino acid positions S228, P329, and / or L235. In some embodiments, the mutations are one or more mutations and include L234A (or another conservative amino acid mutation). In some embodiments, the mutations are one or more mutations and include L235A (or another conservative amino acid mutation). In some embodiments, the mutations are one or more mutations and include P329G (or another conservative amino acid mutation). In some embodiments, the mutations are one or more mutations and include V234A (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations G237A (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations P238S (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations H268A (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations V309L (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations A330S (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations P331S (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations S228P (or another conservative amino acid mutation). In some embodiments, the mutations include one or more mutations L235E (or another conservative amino acid mutation). In some embodiments, the mutations include L234A and L235A (or other conservative amino acid mutations). In some embodiments, the mutations include P329G, L234A, and L235A (or other conservative amino acid mutations).In some embodiments, the mutations include V234A, G237A, P238S, H268A, V309L, A330S, and P331S (or other conservative amino acid mutations) (e.g., for IgG2). In some embodiments, the mutations are one or more mutations and include S228P (or another conservative amino acid mutation) (e.g., for IgG4). In some embodiments, the mutations are one or more mutations and include P329G, S228P, and L235E (or another conservative amino acid mutation) (e.g., for IgG4). In some embodiments, the amino acid position is a position according to any antibody numbering scheme (e.g., Edelman (EU) numbering). In some embodiments, the amino acid position is a position according to Edelman (EU) numbering. In some embodiments, the amino acid position is a position according to the Kabat numbering scheme. In some embodiments, the amino acid position is a position according to the Clothia numbering scheme. In some embodiments, the amino acid position is a position according to the IMGT numbering scheme.

[0107] The modification can include at least one change in the amino acid sequence of the anti-CD2 antibody or antigen-binding fragment thereof Fc region compared to the wild-type Fc region, which results in reduced or eliminated binding of the Fc region to its cognate receptor. Fc receptors are located on immune effector cells, including B cells, NK cells, macrophages, and neutrophils. Without being bound by theory, in wild-type IgG, Fc interaction with Fc receptors (FcR) results in downstream effector cell functions, including stimulating immune cell phagocytic or cytotoxic activity. Reduction or elimination of Fc / FcR interaction results in elimination of effector functions.

[0108] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof exhibits reduced binding to the FcγRIIIA receptor compared to siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof exhibits reduced binding to the FcγRIIA receptor compared to siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof exhibits reduced binding to the FcγRI receptor compared to siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof exhibits increased binding to the FcγRIIIA receptor compared to siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof exhibits increased binding to the FcγRIIA receptor compared to siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof exhibits increased binding to the FcγRI receptor compared to siplizumab. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein bind with about, at least about, or up to about 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the binding capacity exhibited by siplizumab. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments described herein have about or at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95% greater binding affinity (e.g., to FcγRIIA, FcγRIIIA, and / or FcγRI) than the binding affinity exhibited by siplizumab (e.g., to FcγRIIA, FcγRIIIA, and / or FcγRI).In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments described herein have a binding affinity (e.g., to FcγRIIA, FcγRIIIA, and / or FcγRI) that is about or at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95% lower than that exhibited by siplizumab (e.g., to FcγRIIA, FcγRIIIA, and / or FcγRI). Assays for detecting binding events can include, but are not limited to, enzyme-linked immunosorbent assays (ELISAs) and / or surface plasmon resonance (SPR) methods such as Biacore systems.

[0109] In certain embodiments, the Fc region may be modified by any suitable method known in the art. In certain embodiments, the modification may result in Fc silencing. In certain embodiments, the modification may include a mutation in the amino acid sequence of IgG Fc. In certain embodiments, the modification may include a mutation in the glycosylation site (N297) or the consensus sequence including N297. In certain embodiments, the modification may include a mutation that inhibits FcγR and C1q binding. In certain embodiments, these mutations may include any or all of the mutations K322A, L234A, and L235A. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein may be an Fc-less Fab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein is an IgG4 antibody. Without wishing to be bound by theory, the IgG4 subclass is desirable for therapeutic purposes due to its lack of effector functions, including ADCC (Davies and Sutton, Immunol Rev. 2015 Nov; 268(1): 139-15). In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein are IgG2 antibodies. Without wishing to be bound by theory, therapeutically beneficial characteristics of the IgG2 subclass include that IgG2 does not cross the placenta (Einarsdottir et al., PLoS One. 2014 Sep 24; 9(9): e108319) and that IgG2 has low / no Fc receptor binding capacity (Vidarsson et al., Front Immunol. 2014; 5: 520).

[0110] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein may have an antigen-binding variable region and an Fc region. In certain embodiments, the Fc region of the anti-CD2 antibodies or antigen-binding fragments thereof described herein comprises a glycosylation consensus sequence on each of the heavy chains of the antibody. In certain embodiments, the glycosylation consensus sequence is Asn-X-Ser. In certain embodiments, the glycosylation consensus sequence is Asn-X-Thr. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein are glycosylated at Asn297. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein are glycosylated. In certain embodiments, the glycan attached to the asparagine residue may be an N-linked glycan. In certain embodiments, the glycan attached to the asparagine residue may be an O-linked glycan. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein may comprise a single N-linked glycosylation site on Asn297 of the heavy chain.

[0111] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein may be glycosylated at the Fc glycosylation consensus sequence. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein are glycosylated. In certain embodiments, deglycosylation of the anti-CD2 antibodies or antigen-binding fragments thereof described herein is achieved by modifying the Fc region, specifically by introducing a point mutation at position N297. In certain embodiments, the mutation introduced at position 297 (N297) can be, but is not limited to, N297G, N297Q, or N297A. Without being bound by theory, the N297 point mutation can result in lack of glycosylation and silencing of Fc signaling. In certain embodiments, deglycosylation of the anti-CD2 antibodies or antigen-binding fragments thereof described herein is achieved by chemical or enzymatic degradation of the glycan structures of the anti-CD2 antibodies or antigen-binding fragments thereof. In certain embodiments, the chemical or enzymatic methods of glycan degradation preserve the Fc amino acid sequence.

[0112] In certain embodiments, the constant region of the anti-CD2 antibody or antigen-binding fragment thereof described herein can be exchanged with the constant region of an antibody of a different subclass. Without being bound by theory, the variable region is unchanged, but the subclass exchanged antibody retains its specific affinity while interacting with different effector molecules (Valenzuela and Schaub, Transplantation. 2018Jan;102(1S Suppl 1):S7-S13). In certain embodiments, the constant region of the anti-CD2 antibody or antigen-binding fragment thereof described herein can be exchanged with the constant region of a different antibody. In certain embodiments, this exchange results in the anti-CD2 antibody or antigen-binding fragment thereof being an antibody of a different subclass than the original. In certain embodiments, the constant region of the anti-CD2 antibody or antigen-binding fragment thereof can be exchanged with a different antibody while maintaining the specific binding of the variable region. In certain embodiments, the constant region of an anti-CD2 antibody or antigen-binding fragment thereof can be exchanged with a different antibody and the specific variable region can be preserved, wherein the VH region of the anti-CD2 antibody or antigen-binding fragment thereof is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO:1, and the sequence of the VL region of the anti-CD2 antibody or antigen-binding fragment thereof is about or at least about 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO:2.

[0113] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof specifically binds to the same epitope of human CD2 as siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof may be an animal-specific antibody, a human-specific antibody, a chimeric antibody, a humanized antibody, a full-length antibody, an antibody fragment, a single-chain variable fragment (scFv), a naturally occurring antibody, a synthetic antibody, an engineered antibody, an extended anti-CD2 variant in which additional moieties are added to the Fc region (e.g., the moieties can include scFv, a CH2 domain, and / or a CH3 domain), or a combination thereof. In certain embodiments, the antibody Fc region has a point mutation (e.g., at N297) that results in Fc silencing. In certain embodiments, the antibody is an IgG1. In certain embodiments, the antibody is an IgG2. In certain embodiments, the antibody is an IgG4. In certain embodiments, the antibody has a native constant region different from siplizumab. In certain embodiments, the antibody has a native constant region different from siplizumab and a point mutation in the Fc region that results in Fc silencing. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is a humanized anti-CD2 monoclonal antibody. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is siplizumab. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein may have a modified Fc region, which may include, but is not limited to, a point mutation resulting in Fc silencing, a replaced native constant region, or a new native constant region that is Fc silenced and replaced. These different antibody subclasses and modifications produce different versions of anti-CD2 antibodies or antigen-binding fragments thereof, which are outlined in Table 3. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof described herein may be an IgG1, IgG2, or IgG4 subclass of antibody. [Table 3]

[0114] A comparison of anti-CD2 antibodies or antigen-binding fragments thereof is outlined in Table 4. [Table 4]

[0115] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein, including the examples above, have little or no ADCC activity compared to siplizumab, but retain the immunomodulatory effects exhibited by siplizumab. In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof provided herein may have a molecular weight higher than that of an unmodified IgG1 antibody. In certain embodiments, this increase in molecular weight may be achieved by the addition of overlapping regions of the molecule. In certain embodiments, the regions may be attached to the anti-CD2 antibodies or antigen-binding fragments thereof via such means well known in the art, including, but not limited to, chemical conjugation, recombinant fusion, and covalent linkage.

[0116] In certain embodiments, the additional region attached to the anti-CD2 antibody or antigen-binding fragment thereof includes, but is not limited to, an additional variable heavy chain (VH), an additional variable light chain (VL), an scFv comprising a fusion of an additional VH with an additional VL, an additional CH2 domain, or an additional CH3 domain, or other overlapping region of the molecule. In certain embodiments, the additional region may be attached to the Fc region of the anti-CD2 antibody or antigen-binding fragment thereof.

[0117] In certain embodiments, the scFv may be bound to the Fc region of an anti-CD2 antibody or antigen-binding fragment thereof. In certain embodiments, the scFv may comprise a fusion of the VH and VL of siplizumab. In certain embodiments, the scFv may comprise a fusion of the VH and VL, where the VH may comprise the amino acid sequence of SEQ ID NO: 1 and the VL may comprise the amino acid sequence of SEQ ID NO: 2. In certain embodiments, the scFv binds to CD2. In certain embodiments, the CDRs of the scFv are the same as the CDRs of siplizumab. In certain embodiments, the scFv bound to the Fc region of an anti-CD2 antibody or antigen-binding fragment thereof described herein binds to an epitope on CD2. In certain embodiments, the scFv bound to the Fc region of an anti-CD2 antibody or antigen-binding fragment thereof described herein binds to the same epitope of CD2 as siplizumab. In certain embodiments, the scFv may be generated from an IgG2 antibody or an IgG4 antibody.

[0118] In certain embodiments, an additional CH2 domain can be attached to the Fc. In certain embodiments, the CH2 domain comprises an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 18 or 19. In certain embodiments, the additional CH2 domain can be generated from an IgG2 antibody or an IgG4 antibody. In certain embodiments, an additional CH3 domain can be attached to the Fc. In certain embodiments, the CH3 domain comprises an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 20 or 21. In certain embodiments, the additional CH3 domain can be generated from an IgG2 antibody or an IgG4 antibody. In certain embodiments, the additional domain can be attached to the C-terminus of the Fc. In certain embodiments, the domain can be attached to the anti-CD2 antibody or antigen-binding fragment thereof via such means well known in the art, including but not limited to chemical conjugation, recombinant fusion, and covalent linkage. In certain embodiments, the domains may be attached to the anti-CD2 antibody or antigen-binding fragment thereof through such means well known in the art, including, but not limited to, chemical conjugation, recombinant fusion, and covalent linkage. Examples of CD2 antibodies or antigen-binding fragments thereof that may be used in the disclosure and production thereof are described, for example, in U.S. Provisional Patent Application No. 63 / 042,844, which is incorporated herein by reference in its entirety.

[0119] In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein may comprise a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 9, and a CL of SEQ ID NO: 14; a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 10, and a CL of SEQ ID NO: 14; a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 11, and a CL of SEQ ID NO: 14; a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 12, and a CL of SEQ ID NO: 14; or a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 13, and a CL of SEQ ID NO: 14. In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein may comprise a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 9, and a CL of SEQ ID NO: 15; a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 10, and a CL of SEQ ID NO: 15; a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 11, and a CL of SEQ ID NO: 15; a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 12, and a CL of SEQ ID NO: 15; or a VH of SEQ ID NO: 1, a VL of SEQ ID NO: 2, a CH of SEQ ID NO: 13, and a CL of SEQ ID NO: 15.

[0120] In certain embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein may comprise a heavy chain of SEQ ID NO: 16; a VL of SEQ ID NO: 2, and a CL of SEQ ID NO: 14; a heavy chain of SEQ ID NO: 16; a VL of SEQ ID NO: 2, and a CL of SEQ ID NO: 15; a VH of SEQ ID NO: 1; a CH of SEQ ID NO: 9; and a light chain of SEQ ID NO: 17; a VH of SEQ ID NO: 1; a CH of SEQ ID NO: 10; and a light chain of SEQ ID NO: 17; a VH of SEQ ID NO: 1; a CH of SEQ ID NO: 11; and a light chain of SEQ ID NO: 17; a VH of SEQ ID NO: 1; a CH of SEQ ID NO: 12; and a light chain of SEQ ID NO: 17; a VH of SEQ ID NO: 1; a CH of SEQ ID NO: 13; and a light chain of SEQ ID NO: 17; or a heavy chain of SEQ ID NO: 16 and a light chain of SEQ ID NO: 17.

[0121] In certain embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof may comprise extended variants. In certain embodiments, the Fc of the anti-CD2 antibodies or antigen-binding fragments thereof described herein may comprise extended variants, such as those having a molecular weight of 10 kDa, 11 kDa, 12 kDa, 13 kDa, 14 kDa, 15 kDa, 16 kDa, 17 kDa, 18 kDa, 19 kDa, 20 kDa, 21 kDa, 22 kDa, 23 kDa, 24 kDa, 25 kDa, 26 kDa, 27 kDa, 28 kDa, 29 kDa, 30 kDa, 31 kDa, 32 kDa, 33 kDa, 34 kDa, 35 kDa, 36 kDa, 37 kDa, 38 kDa, 39 kDa, 40 kDa, 41 kDa, 42 kDa, 43 kDa, 44 kDa, 45 kDa, 46 kDa, 47 kDa, 48 kDa, 49 kDa, 50 kDa, 51 kDa, 52 kDa, 53 kDa, 54 kDa, 55 kDa, 56 kDa, 57 kDa, 58 kDa, 59 kDa, 60 kDa, 61 kDa, 62 kDa, 63 kDa, 64 kDa, 65 kDa, 66 kDa, 67 kDa, 68 kDa, 69 kDa, 70 kDa, 71 kDa, 72 kDa, 73 kDa, 74 and including additional regions such as 1 kDa, 32 kDa, 33 kDa, 34 kDa, 35 kDa, 36 kDa, 37 kDa, 38 kDa, 39 kDa, 40 kDa, 41 kDa, 42 kDa, 43 kDa, 44 kDa, 45 kDa, 46 kDa, 47 kDa, 48 kDa, 49 kDa, 50 kDa, 51 kDa, 52 kDa, 53 kDa, 54 kDa, 55 kDa, 56 kDa, 57 kDa, 58 kDa, 59 kDa, or 60 kDa increments.In certain embodiments, the Fc of an anti-CD2 antibody or antigen-binding fragment thereof described herein is selected from the group consisting of an anti-CD2 antibody, ... 22kDa, 18kDa~23kDa, 19kDa~24kDa, 20kDa~25kDa, 21kDa~26kDa, 22kDa~27kDa, 23kDa~28kDa, 24 kDa~29kDa, 25kDa~30kDa, 26kDa~31kDa, 27kDa~32kDa, 28kDa~33kDa, 29kDa~34kDa, 30kDa~35kDa , 31kDa~36kDa, 32kDa~37kDa, 33kDa~38kDa, 34kDa~39kDa, 35kDa~40kDa, 36kDa~41kDa, 37kDa~4 2kDa, 38kDa~43kDa, 39kDa~44kDa, 40kDa~45kDa, 41kDa~46kDa, 42kDa~47kDa, 43kDa~48kDa, 44kDa a-49 kDa, 45 kDa-50 kDa, 46 kDa-51 kDa, 47 kDa-52 kDa, 48 kDa-53 kDa, 49 kDa-54 kDa, 50 kDa-55 kDa, 51 kDa-56 kDa, 52 kDa-57 kDa, 53 kDa-58 kDa, 54 kDa-59 kDa, or 55 kDa-60 kDa.

[0122] In certain embodiments, overlapping regions of an anti-CD2 antibody or antigen-binding fragment thereof can be joined to a molecule to generate extended mutants. In certain embodiments, these regions can be joined to the Fc region of an anti-CD2 antibody or antigen-binding fragment thereof through such means well known in the art, including but not limited to chemical conjugation, recombinant fusion, and covalent linkage.

[0123] In certain embodiments, the expanded variants of the anti-CD2 antibody or antigen-binding fragment thereof may be derived from IgG1, IgG2, or IgG4. In certain embodiments, additional scFvs may be attached to the Fc of the anti-CD2 antibody or antigen-binding fragment thereof to generate the expanded variants. In certain embodiments, the scFv may comprise a VH and a VL, where the VH may comprise an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO:1, and the VL may comprise an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO:2.

[0124] In certain embodiments, an additional CH2 domain can be attached to the Fc of an anti-CD2 antibody or antigen-binding fragment thereof to generate an expanded variant. In certain embodiments, the additional CH2 domain can comprise an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 18 or 19. In certain embodiments, an additional CH3 domain can be attached to the Fc of an anti-CD2 antibody or antigen-binding fragment thereof to generate an expanded variant. In certain embodiments, the additional CH3 domain can comprise an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 20 or 21. In some embodiments, the additional fragment or domain can be attached to the C-terminus of the Fc. In certain embodiments, the expanded anti-CD2 variant can be an IgG2 antibody. In certain embodiments, the expanded anti-CD2 variant can be an IgG4 antibody. Details of the expanded anti-CD2 variants are shown in Table 5.

[0125] In certain embodiments, the additional region that binds to an anti-CD2 antibody or antigen-binding fragment thereof may comprise an unrelated or artificial amino acid sequence. In certain embodiments, the additional region that binds to an anti-CD2 antibody or antigen-binding fragment thereof may comprise a fragment, such as a structural domain, from another human protein. In certain embodiments, the additional region that binds to an anti-CD2 antibody or antigen-binding fragment thereof may comprise a fragment of a domain from another human protein. In certain embodiments, the addition of such additional regions does not interfere with the binding activity of the parent anti-CD2 antibody or antigen-binding fragment thereof in humans and / or does not increase the immunogenicity of the resulting anti-CD2 binding agent compared to the parent anti-CD2 antibody or antigen-binding fragment thereof. [Table 5]

[0126] In certain embodiments, the conditioning regimens provided herein comprise administering an anti-CD2 antibody or antigen-binding fragment thereof to the transplant recipient prior to transplantation and / or cell infusion. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the recipient 1 day prior to transplantation and / or cell infusion, 2 days prior to transplantation and / or cell infusion, 3 days prior to transplantation and / or cell infusion, 4 days prior to transplantation and / or cell infusion, 5 days prior to transplantation and / or cell infusion, 6 days prior to transplantation and / or cell infusion, 7 days prior to transplantation and / or cell infusion, 8 days prior to transplantation and / or cell infusion, 9 days prior to transplantation and / or cell infusion, 10 days prior to transplantation and / or cell infusion, or more than 10 days prior to transplantation and / or cell infusion. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the recipient 1 day after transplantation and / or cell infusion, 2 days after transplantation and / or cell infusion, 3 days after transplantation and / or cell infusion, 4 days after transplantation and / or cell infusion, 5 days after transplantation and / or cell infusion, 6 days after transplantation and / or cell infusion, 7 days after transplantation and / or cell infusion, 8 days after transplantation and / or cell infusion, 9 days after transplantation and / or cell infusion, 10 days after transplantation and / or cell infusion, or more than 10 days after transplantation and / or cell infusion. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the recipient on the same day as transplantation and / or cell infusion.In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered 6 days before transplantation and / or cell infusion, 1 day before transplantation and / or cell infusion, the same day as transplantation and / or cell infusion, and 1 day after transplantation and / or cell infusion; 6 days before transplantation and / or cell infusion, 1 day before transplantation and / or cell infusion, the same day as transplantation and / or cell infusion, 1 day after transplantation and / or cell infusion, and 6 days after transplantation and / or cell infusion; 1 day before transplantation and / or cell infusion; 1 day after transplantation and / or cell infusion; the same day as transplantation and / or cell infusion; 6 days before transplantation and / or cell infusion; 6 days after transplantation and / or cell infusion; 1 day before transplantation and / or cell infusion and the same day as transplantation and / or cell infusion; 1 day after transplantation and / or cell infusion and the same day as transplantation and / or cell infusion; 1 day before transplantation and / or cell infusion and 1 day after transplantation and / or cell infusion; 1 day before transplantation and / or cell infusion and 1 day after transplantation and / or cell infusion; 1 and / or 2 days before transplantation and / or cell infusion; 2 and / or 3 days prior to transplantation and / or cell infusion; 3 and / or 4 days prior to transplantation and / or cell infusion; 1 and / or 2 and / or 3 days prior to transplantation and / or cell infusion; 1 and / or 2 and / or 3 days prior to transplantation and / or cell infusion; 1 and / or 2 and / or 3 and / or 4 days prior to transplantation and / or cell infusion; 1 and / or 2 and / or 3 and / or 4 days prior to transplantation and / or cell infusion, and / or 5 and / or 6 days prior to transplantation and / or cell infusion; The recipient is administered 1 and / or 2 days after transplantation; 2 and / or 3 days after transplantation and / or cell infusion; 3 and / or 4 days after transplantation and / or cell infusion; 1 and / or 2 and / or 3 days after transplantation and / or cell infusion; 1 and / or 2 and / or 3 days after transplantation and / or cell infusion; 1 and / or 2 and / or 3 and / or 4 days after transplantation and / or cell infusion; 1 and / or 2 and / or 3 and / or 4 days after transplantation and / or cell infusion; 1 and / or 2 and / or 3 and / or 4 days after transplantation and / or cell infusion. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is not administered to the recipient 2 days prior to transplantation and / or cell infusion.In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the recipient about, at least about, or up to about 1 time (or 1 day), 2 times (or 2 different days), 3 times (or 3 different days), 4 times (or 4 different days), 5 times (or 5 different days), 6 times (or 6 different days), 7 times (or 7 different days), 8 times (or 8 different days), 9 times (or 9 different days), 10 times (or 10 different days), or more than 10 times (or more than 10 different days) prior to transplantation and / or cell infusion. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the recipient about, at least about, or up to about once (or one day), twice (or on two different days), three times (or on three different days), four times (or on four different days), five times (or on five different days), six times (or on six different days), seven times (or on seven different days), eight times (or on eight different days), nine times (or on nine different days), ten times (or on ten different days), or more than ten times (or on more than ten different days) after transplantation and / or cell infusion. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the recipient 1 day and 6 days before transplantation and / or cell infusion. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the recipient 1 day, 6 days before transplantation and / or cell infusion, on the day of transplantation and / or cell infusion, 1 day after transplantation and / or cell infusion, and / or 6 days after transplantation and / or cell infusion. In certain embodiments, a test dose of anti-CD2 antibody or its antigen-binding fragment may be administered. In some embodiments, the anti-CD2 antibody or its antigen-binding fragment is administered to the subject after transplantation. In some embodiments, the anti-CD2 antibody or its antigen-binding fragment is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In certain embodiments, administering the test dose is optional.In some embodiments, when the anti-CD2 antibody or antigen-binding fragment thereof is administered to the transplant recipient more than once or on more than one day, the dosage is the same on all days and / or the same per administration. In some embodiments, when the anti-CD2 antibody or antigen-binding fragment thereof is administered to the transplant recipient more than once or on more than one day, the dosage is not the same on all days and / or the same per administration. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the transplant recipient at a dose of 0.6 mg / kg. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is not administered to the transplant recipient at a dose of 0.1 mg / kg. In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is not administered to the transplant recipient at a dose of 0.1 mg / kg two days prior to transplantation and / or cell infusion.

[0127] In certain embodiments, the dose of the anti-CD2 antibody or antigen-binding fragment thereof administered to the recipient in the postoperative regimen is the same as that administered in the conditioning regimen. In certain embodiments, the dose of the anti-CD2 antibody or antigen-binding fragment thereof administered to the recipient in the postoperative regimen is different from that administered in the conditioning regimen.

[0128] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the transplant recipient at a dose of about, at least about, or up to about 0.05 mg / kg / dose, 0.1 mg / kg / dose, 0.15 mg / kg / dose, 0.2 mg / kg / dose, 0.25 mg / kg / dose, 0.3 mg / kg / dose, 0.35 mg / kg / dose, 0.4 mg / kg / dose, 0.45 mg / kg / dose, 0.5 mg / kg / dose, 0.55 mg / kg / dose, 0.6 mg / kg / dose, 0.65 mg / kg / dose, 0.7 mg / kg / dose, 0.75 mg / kg / dose, 0.8 mg / kg / dose, 0.85 mg / kg / dose, 0.9 mg / kg / dose, 0.95 mg / kg / dose, or 1.0 mg / kg / dose. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the transplant recipient at a dose of about 0.6 mg / kg. In certain embodiments, the anti-CD2 antibody is administered to the transplant recipient at a dose range of about, at least about, or up to about 0.1-0.3 mg / dose, 0.2-0.4 mg / dose, 0.3-0.5 mg / dose, 0.4-0.6 mg / dose, 0.45-0.65 mg / dose, 0.5-0.7 mg / dose, 0.55-0.75 mg / dose, 0.6-0.8 mg / dose, 0.65-0.85 mg / dose, 0.7-0.9 mg / dose, or 0.8-1.0 mg / dose. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the transplant recipient at a dose of 0.1 mg / kg / dose. In a specific embodiment, the anti-CD2 antibody or antigen-binding fragment thereof is administered to the transplant recipient at a dose of 0.6 mg / kg / dose.

[0129] In some embodiments, an anti-CD2 antibody or antigen-binding fragment thereof described herein is administered to a subject in need thereof at about, at least about, or up to about 0.01 mg / kg / dose, 0.02 mg / kg / dose, 0.03 mg / kg / dose, 0.04 mg / kg / dose, 0.05 mg / kg / dose, 0.1 mg / kg / dose, 0.15 mg / kg / dose, 0.2 mg / kg / dose, 0.25 mg / kg / dose, 0.3 mg / kg / dose, 0.35 mg / kg / dose, 0.4 mg / kg / dose, 0.45 mg / kg / dose, 0. 5mg / kg / dose, 0.55mg / kg / dose, 0.6mg / kg / dose, 0.65mg / kg / dose, 0.7mg / kg / dose, 0.75mg / kg / dose, 0.8mg / kg / dose, 0.85mg / kg / dose, 0.9mg / kg / dose, 0.95mg / dose kg / dose, 1.0mg / kg / dose, 2.0mg / kg / dose, 3.0mg / kg / dose, 4.0mg / kg / dose, 5.0mg / kg / dose, 6.0mg / kg / dose, 7.0mg / kg / dose, 8.0mg / kg / dose, 9.0mg / kg / dose, 10m g / kg / dose, 11mg / kg / dose, 12mg / kg / dose, 13mg / kg / dose, 14mg / kg / dose, 15mg / kg / dose, 16mg / kg / dose, 17mg / kg / dose, 18mg / kg / dose, 19mg / kg / dose, 20mg / kg / dose , 21mg / kg / dose, 22mg / kg / dose, 23mg / kg / dose, 24mg / kg / dose, 25mg / kg / dose, 26mg / kg / dose, 27mg / kg / dose, 28mg / kg / dose, 29mg / kg / dose, 30mg / kg / dose, 31mg / k g / dose, 32 mg / kg / dose, 33 mg / kg / dose, 34 mg / kg / dose, 35 mg / kg / dose, 36 mg / kg / dose, 37 mg / kg / dose, 38 mg / kg / dose, 39 mg / kg / dose, 40 mg / kg / dose, 41 mg / kg / dose, 42 mg / kg / dose, 43 mg / kg / dose, 44 mg / kg / dose, 45 mg / kg / dose, 46 mg / kg / dose, 47 mg / kg / dose, 48 mg / kg / dose, 49 mg / kg / dose, or 50 mg / kg / dose.In some embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein are administered at 0.1-0.3 mg / kg / dose, 0.2-0.4 mg / kg / dose, 0.3-0.5 mg / kg / dose, 0.4-0.6 mg / kg / dose, 0.45-0.65 mg / kg / dose, 0.5-0.7 mg / kg, 0.55-0.75 mg / kg / dose, 0.6-0.8 mg / kg / dose, 0.65-0.85 mg / kg / dose, 0.7-0.9 mg / kg / dose, 0.8-1.0 mg / kg / dose, 1.0 mg / kg / dose or The compound may be administered to a subject in need thereof at a dose of 6.0 mg / kg / dose, 5.0 mg / kg / dose to 10 mg / kg / dose, 9.0 mg / kg / dose to 15 mg / kg / dose, 14 mg / kg / dose to 20 mg / kg / dose, 19 mg / kg / dose to 25 mg / kg / dose, 24 mg / kg / dose to 30 mg / kg / dose, 29 mg / kg / dose to 35 mg / kg / dose, 34 mg / kg / dose to 40 mg / kg / dose, 39 mg / kg / dose to 45 mg / kg / dose, or 44 mg / kg / dose to 50 mg / kg / dose.

[0130] In some embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered at about, at least about, or up to about 1000 mg, 1100 mg, 1200 mg, 1300 mg, 1400 mg, 1500 mg, 1600 mg, 1700 mg, 1800 mg, 1900 mg, 2000 mg, 2100 mg, 2200 mg, 2300 mg, 2400 mg, 2500 mg, 2600 mg, 2700 mg, 2800 mg, 2900 mg, 3000 mg, 3100 mg, 3200 mg, 3300 mg, 3400 mg, 3500 mg, 3600 mg, 3700 mg, 3800 mg, 3900 mg, 4000 mg, 4100 mg, 4200 mg, 4300 mg, 4400 mg, 4500 mg, 4600 mg, 4700 mg, 4800 mg, 4900 mg, 5000 mg, 5100 mg, 5200 mg, 5300 mg, 5400 mg, 5500 mg, 5600 mg, 5700 mg, 5800 mg, 5900 mg, 6000 mg, 6100 mg, 6200 mg, 6300 mg, 6400 mg, 6500 mg, 6600 mg, 6700 mg, 6800 mg, 6900 mg, 7000 mg, 7100 mg, 7200 mg, 7300 mg, 7400 mg, 7500 mg, 7600 mg, 7700 mg, 7800 mg In some embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein may be administered to a transplant recipient in an amount of 2400 mg, 3700 mg, 3800 mg, 3900 mg, 4000 mg, 4100 mg, 4200 mg, 4300 mg, 4400 mg, 4500 mg, 4600 mg, 4700 mg, 4800 mg, 4900 mg, 5000 mg, 1000 mg to 1600 mg, 1500 mg to 2100 mg, 2000 mg to 2600 mg, 2500 mg to 3100 mg, 3000 mg to 3600 mg, 3500 mg to 4100 mg, 4000 mg to 4600 mg, or 4500 mg to 5000 mg. In some embodiments, the anti-CD2 antibodies or antigen-binding fragments thereof described herein may be administered to a subject in need thereof in an amount of 2400 mg.

[0131] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intra-arterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, intraperitoneally, or any route of administration that allows for depletion of T cells in the recipient. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is administered intravenously.

[0132] In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof is a humanized monoclonal antibody. In certain embodiments, the anti-CD2 antibody or antigen-binding fragment thereof can be siplizumab (MEDI-507). In certain embodiments, administration of the anti-CD2 antibody or antigen-binding fragment thereof can be modified as described herein to achieve and / or maintain mixed chimerism.

[0133] Without wishing to be bound by theory, the anti-CD2 antibody or antigen-binding fragment thereof increases the level of regulatory T cells in the recipient. Specifically, the anti-CD2 antibody or antigen-binding fragment thereof increases the level of FOXP3 in the recipient. + The level of regulatory T cells was measured, for example, by FOXP3 without treatment with an anti-CD2 antibody or an antigen-binding fragment thereof. + The increase may be about or at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 125%, 150%, 175%, 200%, or at least 250% compared to regulatory T cells.

[0134] In some embodiments, the methods described herein comprise administration of an anti-CD2 antibody or antigen-binding fragment thereof, and one or more immunosuppressive agents. Without being bound by theory, immunosuppressants that can be combined with administration of the anti-CD2 antibodies or antigen-binding fragments thereof described herein include, but are not limited to, tacrolimus, cyclosporine, belatacept, anti-CD40 antibodies, anti-CD40L (CD154), anti-OX40, anti-OX40L antibodies, anti-CD28 antibodies, anti-CD27 antibodies, anti-ICOS antibodies, anti- or agonistic 4-1BB (CD137) antibodies, BCL-2 inhibitors, mycophenolate mofetil, mycophenolic acid derivatives such as Myfortic (enteric coated mycophenolate sodium), sirolimus, everolimus, anti-thymoglobulin, basiliximab, prednisone, cyclophosphamide, fludarabine, and rituximab (Adams et al., J Immunol, 2016, 197(6)2045-2050; Kinnear et al., J Immunol, 2016, 197(6)2045-2050). al.,Transplantation.2013Feb27;95(4):527-535;Zhang and Vignali,Immunity.2016May17;44(5):1034-51).

[0135] 5.3.3 Cyclophosphamide Cyclophosphamide, as used herein, is a compound administered to a recipient to suppress the immune system. Cyclophosphamide (2-[bis(2-chloroethyl)amino]tetrahydro-2H-1,3,2-oxyazaphosphorine 2-oxide hydrate) is administered to induce tolerance to the transplanted organ, and trade names for cyclophosphamide include Cytoxan®, Neosar®, and Endoxan®.

[0136] In certain embodiments, the conditioning regimen provided herein comprises administering cyclophosphamide to the transplant recipient before transplantation. In some embodiments, cyclophosphamide can be administered to the recipient 3 days before transplantation, 4 days before transplantation, 5 days before transplantation, 6 days before transplantation, 3 and 4 days before transplantation, 4 and 5 days before transplantation, 5 and 6 days before transplantation, 3 and 4 and 5 days before transplantation, or 4 and 5 and 6 days before transplantation. In certain embodiments, cyclophosphamide can be administered to the recipient 5 and 6 days before transplantation. In certain embodiments, cyclophosphamide can be administered to the recipient 4 and 5 days before transplantation.

[0137] In certain embodiments, the conditioning regimens provided herein include administering cyclophosphamide to the transplant recipient prior to transplantation and / or cell infusion. In some embodiments, cyclophosphamide is administered to the recipient 1 day prior to transplantation and / or cell infusion, 2 days prior to transplantation and / or cell infusion, 3 days prior to transplantation and / or cell infusion, 4 days prior to transplantation and / or cell infusion, 5 days prior to transplantation and / or cell infusion, 6 days prior to transplantation and / or cell infusion, 7 days prior to transplantation and / or cell infusion, 8 days prior to transplantation and / or cell infusion, 9 days prior to transplantation and / or cell infusion, 10 days prior to transplantation and / or cell infusion, or more than 10 days prior to transplantation and / or cell infusion. In some embodiments, cyclophosphamide is administered to the recipient 1 day after transplantation and / or cell infusion, 2 days after transplantation and / or cell infusion, 3 days after transplantation and / or cell infusion, 4 days after transplantation and / or cell infusion, 5 days after transplantation and / or cell infusion, 6 days after transplantation and / or cell infusion, 7 days after transplantation and / or cell infusion, 8 days after transplantation and / or cell infusion, 9 days after transplantation and / or cell infusion, 10 days after transplantation and / or cell infusion, or more than 10 days after transplantation and / or cell infusion. In some embodiments, cyclophosphamide is administered to the recipient on the same day as transplantation and / or cell infusion.In some embodiments, cyclophosphamide is administered 4 days prior to transplantation and / or cell infusion and / or 5 days prior to transplantation and / or cell infusion; on the same day as transplantation and / or cell infusion; 4 days prior to transplantation and / or cell infusion; 5 days prior to transplantation and / or cell infusion; 1 day prior to transplantation and / or cell infusion; 1 day after transplantation and / or cell infusion; on the same day as transplantation and / or cell infusion; 1 day and / or 2 days prior to transplantation and / or cell infusion; 2 days and / or 3 days prior to transplantation and / or cell infusion; 3 days and / or 4 days prior to transplantation and / or cell infusion; 4 days and / or 5 days prior to transplantation and / or cell infusion; 1 day and / or 2 days and / or 3 days prior to transplantation and / or cell infusion; 1 day and / or 2 days and / or 3 days prior to transplantation and / or cell infusion; 1 day and / or 2 days and / or 3 days prior to transplantation and / or cell infusion; 1 day and / or 2 days and / or 4 days prior to transplantation and / or cell infusion; 1 day and / or 2 days and and / or 3 days and / or 4 days and / or 5 days before transplantation and / or cell infusion; 1 day and / or 2 days and / or 3 days and / or 4 days and / or 5 days before transplantation and / or cell infusion; 1 day and / or 2 days after transplantation and / or cell infusion; 2 days and / or 3 days after transplantation and / or cell infusion; 3 days and / or 4 days after transplantation and / or cell infusion; 1 day and / or 2 days and / or 3 .... In some embodiments, cyclophosphamide is administered to the recipient about, at least about, or up to about 1 time (or 1 day), 2 times (or 2 different days), 3 times (or 3 different days), 4 times (or 4 different days), 5 times (or 5 different days), 6 times (or 6 different days), 7 times (or 7 different days), 8 times (or 8 different days), 9 times (or 9 different days), 10 times (or 10 different days), or more than 10 times (or more than 10 different days) prior to transplantation and / or cell infusion.In some embodiments, cyclophosphamide is administered to the recipient about, at least about, or up to about once (or one day), twice (or two different days), three times (or three different days), four times (or four different days), five times (or five different days), six times (or six different days), seven times (or seven different days), eight times (or eight different days), nine times (or nine different days), ten times (or ten different days), or more than ten times (or more than ten different days) after transplantation and / or cell infusion. In certain embodiments, cyclophosphamide is administered to the recipient four and five days prior to transplantation and / or cell infusion. In certain embodiments, a test dose of cyclophosphamide may be administered. In certain embodiments, administration of the test dose is optional. In some embodiments, if cyclophosphamide is administered to the transplant recipient more than once or on more than one day, the dosage is the same on all days and / or the same per administration. In some embodiments, when cyclophosphamide is administered to a transplant recipient more than once or on more than one day, the dosage is not the same on all days and / or the same per administration.In certain embodiments, the dose of cyclophosphamide administered to a recipient in a postoperative regimen is the same as the dose administered in a conditioning regimen.In certain embodiments, the dose of cyclophosphamide administered to a recipient in a postoperative regimen is different from the dose administered in a conditioning regimen.In some embodiments, cyclophosphamide is administered prophylactically.

[0138] In certain embodiments, the postoperative treatment regimen provided herein comprises administering cyclophosphamide to the transplant recipient. In certain embodiments, cyclophosphamide can be administered on the day of transplantation, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, or 10 days after transplantation. In certain embodiments, cyclophosphamide can be administered on the day of transplantation until 2 days after surgery, on the day of transplantation until 4 days after surgery, on the day of transplantation until 6 days after surgery, on the day of transplantation until 7 days after surgery, on the day of transplantation until 8 days after surgery, on the day of transplantation until 9 days after surgery, or on the day of transplantation until 10 days after surgery. In certain embodiments, cyclophosphamide can be administered on the day of transplantation until 7 days after surgery.

[0139] In certain embodiments, cyclophosphamide is administered at a dose of about, at least about, or up to about 5 mg / kg / dose, 10 mg / kg / dose, 11 mg / kg / dose, 12 mg / kg / dose, 13 mg / kg / dose, 13.5 mg / kg / dose, 14 mg / kg / dose, 14.5 mg / kg / dose, 15 mg / kg / dose, 15.5 mg / kg / dose, 16 mg / kg / dose, 17 mg / kg / dose, 18 mg / kg / dose, 19 mg / kg / dose, 20 mg / kg / dose, 22.5 mg / kg / dose, 25 mg / kg / dose, 30 mg / kg / dose, The cyclophosphamide may be administered to the transplant recipient at a dose of 35 mg / kg / dose, 40 mg / kg / dose, 45 mg / kg / dose, 50 mg / kg / dose, 55 mg / kg / dose, 56 mg / kg / dose, 57 mg / kg / dose, 58 mg / kg / dose, 59 mg / kg / dose, 60 mg / kg / dose, 61 mg / kg / dose, 62 mg / kg / dose, 63 mg / kg / dose, 64 mg / kg / dose, 65 mg / kg / dose, 70 mg / kg / dose, 75 mg / kg / dose, 80 mg / kg / dose, 85 mg / kg / dose, or 90 mg / kg / dose. In certain embodiments, the cyclophosphamide may be administered to the transplant recipient at a dose of about 60 mg / kg. In certain embodiments, the cyclophosphamide may be administered to the transplant recipient at a dose of about 22.5 mg / kg. In certain embodiments, cyclophosphamide may be administered to the transplant recipient at a dose of at least about, or up to about, 60 mg / kg. In certain embodiments, cyclophosphamide may be administered to the transplant recipient at a dose of at least about, or up to about, 22.5 mg / kg. In certain embodiments, cyclophosphamide may be administered to the transplant recipient at a dose range of 5-15 mg / kg / dose, 10-20 mg / kg / dose, 15-25 mg / kg / dose, 15-65 mg / kg / dose, 20-30 mg / kg / dose, 25-35 mg / kg / dose, 30-40 mg / kg / dose, 35-45 mg / kg / dose, 40-50 mg / kg / dose, 45-55 mg / kg / dose, 50-60 mg / kg, 55-65 mg / kg / dose, 60-70 mg / kg / dose, 65-75 mg / kg / dose, 70-80 mg / kg / dose, 75-85 mg / kg / dose, or 80-90 mg / kg / dose.In certain embodiments, cyclophosphamide may be administered to the transplant recipient at a dose of about 60 mg / kg / dose. In certain embodiments, cyclophosphamide may be administered to the transplant recipient at a dose of about 50 mg / kg / dose. In certain embodiments, cyclophosphamide may be administered to the transplant recipient at a dose of about 22.5 mg / kg / dose. In certain embodiments, cyclophosphamide may be administered to the transplant recipient at a dose of about 14.5 mg / kg / dose.

[0140] In certain embodiments, the conditioning regimen may include administering cyclophosphamide and fludarabine to the patient. In certain embodiments, when fludarabine is administered to the patient, without being bound by theory, cyclophosphamide may be administered at a lower dose than if the patient were not receiving fludarabine. When fludarabine is administered as a component of the conditioning regimen, the concentration of cyclophosphamide administered may include 5-15 mg / kg / dose, 10-20 mg / kg / dose, 15-25 mg / kg / dose, 20-30 mg / kg / dose, 25-35 mg / kg / dose, 30-40 mg / kg / dose, 35-45 mg / kg / dose, and 40-50 mg / kg / dose. In some embodiments, fludarabine is administered at a dose of 10 mg / m 2 and cyclophosphamide is administered to the subject at 22.5 mg / kg.

[0141] In certain embodiments, cyclophosphamide may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, intraperitoneally, or any route of administration that allows for adequate activity of cyclophosphamide by the recipient. In certain embodiments, cyclophosphamide is administered intravenously.

[0142] In certain embodiments, total body irradiation may be used in place of cyclophosphamide. In certain embodiments, administration of cyclophosphamide may be altered as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0143] 5.3.4 B-cell depleting antibodies (e.g., rituximab) Rituximab, as used herein, is an anti-CD20 chimeric monoclonal antibody administered to a recipient to suppress the immune system. Rituximab has a mouse variable region and a human constant region and Fc region. The Fc region can bind human complement and initiate antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Administration of rituximab results in the depletion of B cells.

[0144] In certain embodiments, the conditioning regimens provided herein comprise administering a B cell depleting antibody (e.g., rituximab) to the transplant recipient. In some embodiments, one dose of the B cell depleting antibody (e.g., rituximab) may be administered prior to transplant. In some embodiments, two doses of the B cell depleting antibody (e.g., rituximab) may be administered prior to transplant. In some embodiments, more than two doses of the B cell depleting antibody (e.g., rituximab) may be administered prior to transplant.

[0145] In some embodiments, a B cell depleting antibody (e.g., rituximab) may be administered to the recipient 1 day prior to transplant, 2 days prior to transplant, 3 days prior to transplant, 4 days prior to transplant, 5 days prior to transplant, 6 days prior to transplant, 7 days prior to transplant, 8 days prior to transplant, 9 days prior to transplant, 10 days prior to transplant, 9 and 2 days prior to transplant, 1 day and 4 days prior to transplant, 1 day and 5 days prior to transplant, 1 and 6 days prior to transplant, 2 days and 5 days prior to transplant, 2 days and 6 days prior to transplant, 2 days and 7 days prior to transplant, 3 days and 6 days prior to transplant, 3 days and 7 days prior to transplant, 3 days and 8 days prior to transplant, 1 day and 3 days and 5 days prior to transplant, 2 days and 4 days and 6 days prior to transplant, 3 days and 5 days prior to transplant, or 4 days and 6 days prior to transplant. In certain embodiments, a B cell depleting antibody (e.g., rituximab) may be administered to the recipient 2 and 7 days prior to transplant. In certain embodiments, a B cell depleting antibody (e.g., rituximab) is not administered to the recipient 7 days prior to transplant.

[0146]

[0147] In certain embodiments, the post-operative treatment regimen provided herein comprises administering a B cell depleting antibody (e.g., rituximab) to the transplant recipient. In some embodiments, one dose of the B cell depleting antibody (e.g., rituximab) can be administered post-operatively. In some embodiments, two doses of the B cell depleting antibody (e.g., rituximab) can be administered post-operatively. In some embodiments, more than two doses of the B cell depleting antibody (e.g., rituximab) can be administered post-operatively.

[0148] In some embodiments, the B cell depleting antibody (e.g., rituximab) is administered 3 days after transplant, 4 days after transplant, 5 days after transplant, 6 days after transplant, 7 days after transplant, 8 days after transplant, 9 days after transplant, 10 days after transplant, 11 days after transplant, 12 days after transplant, 13 days after transplant, 3 and 9 days after transplant, 3 and 10 days after transplant, 4 and 10 days after transplant, 4 and 11 days after transplant, Rituximab may be administered to the recipient 5 days and 11 days after transplantation, 5 days and 12 days after transplantation, 6 days and 12 days after transplantation, 6 days and 13 days after transplantation, 3 days, 6 days and 9 days after transplantation, 4 days, 7 days and 10 days after transplantation, 5 days, 8 days and 12 days after transplantation, 6 days, 9 days and 12 days after transplantation, or 7 days, 10 days and 12 days after transplantation. In certain embodiments, rituximab may be administered to the recipient 5 days and 12 days after transplantation.

[0149] In certain embodiments, the B cell depleting antibody (e.g., rituximab) is administered at a dose of about, at least about, or up to about 200 mg / m 2 / dose, 225mg / m 2 / dose, 250mg / m 2 / dose, 275mg / m 2 / dose, 300mg / m 2 / dose, 325mg / m 2 / dose, 350mg / m 2 / dose, 355mg / m 2 / dose, 360mg / m 2 / dose, 365mg / m 2 / dose, 366mg / m2 / dose, 367mg / m 2 / dose, 368mg / m 2 / dose, 369mg / m 2 / dose, 370mg / m 2 / dose, 371mg / m 2 / dose, 372mg / m 2 / dose, 373mg / m 2 / dose, 374mg / m 2 / dose, 375mg / m 2 / dose, 380mg / m 2 / dose, 385mg / m 2 / dose, 390mg / m 2 / dose, 395mg / m 2 / dose, 400mg / m 2 / dose, 425mg / m 2 / dose, 450mg / m 2 / dose, 475mg / m 2 / dose, 500mg / m 2 / dose or 500 mg / m 2 In certain embodiments, rituximab may be administered to a transplant recipient at a dose of 375 mg / m 2 / dose may be administered to the recipient.

[0150] In certain embodiments, the B cell depleting antibody (e.g., rituximab) is administered at a dose of about, at least about, or up to about 200-250 mg / m 2 / dose, 225-275mg / m 2 / dose, 250~300mg / m 2 / dose, 275~325mg / m 2 / dose, 300~350mg / m 2 / dose, 325~375mg / m 2 / dose, 350~400mg / m 2 / dose, 375~425mg / m 2 / dose, 400~450mg / m 2 / dose, 425~475mg / m 2 / dose, or 450-500 mg / m 2 / dose may be administered to the transplant recipient.

[0151] In certain embodiments, the B cell depleting antibody (e.g., rituximab) may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, or intraperitoneally, or any other route of administration that allows for adequate activity of the B cell depleting antibody (e.g., rituximab) by the recipient. In certain embodiments, the B cell depleting antibody (e.g., rituximab) is administered intravenously. In certain embodiments, administration of the B cell depleting antibody (e.g., rituximab) may be altered as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0152] In certain embodiments, replacement compounds may be used in place of rituximab. These compounds may include plasmapheresis, alemtuzumab (Lemtrada®), IdeS (Imflidase®), and anti-CD19 directed therapies.

[0153] 5.3.5 Fludarabine Fludarabine, as used herein, is a purine analog administered to a recipient to suppress the immune system. Fludarabine (9H-purin-6-amine, 2-fluoro-9-(5-0-phosphono-0-D-arabino-furanosyl) (2-fluoro-ara-AMP) is also recognized by the trade names Oforta® and Fludara®. In some embodiments, a comparable agent or another (e.g., equivalent) antineoplastic agent can be administered to the subject instead of or in addition to fludarabine. In some embodiments, the comparable agent or another (e.g., equivalent) antineoplastic agent is administered at the same dose and / or on the same day(s) as provided herein for fludarabine. In some embodiments, the comparable agent or another (e.g., equivalent) antineoplastic agent is administered using a dose according to the product label of the antineoplastic agent or as known / determined by one of ordinary skill in the art.

[0154]

[0155] In certain embodiments, the postoperative treatment regimen provided herein comprises administering tacrolimus to the transplant recipient.In some embodiments, one dose of fludarabine can be administered postoperatively.In some embodiments, two doses of fludarabine can be administered postoperatively.In some embodiments, more than two doses of fludarabine can be administered postoperatively.

[0156] In certain embodiments, the conditioning regimen provided herein comprises administering fludarabine to the transplant recipient prior to transplant. In certain embodiments, the conditioning regimen comprises administration of fludarabine and administration of cyclophosphamide. In certain embodiments, the conditioning regimen comprises administration of fludarabine and administration of low dose cyclophosphamide, where the dose of cyclophosphamide may include 5-15 mg / kg / dose, 10-20 mg / kg / dose, 15-25 mg / kg / dose, 20-30 mg / kg / dose, 25-35 mg / kg / dose, 30-40 mg / kg / dose, 35-45 mg / kg / dose, and 40-50 mg / kg / dose.

[0157] In some embodiments, fludarabine can be administered to the recipient 1 day before transplantation, 2 days before transplantation, 3 days before transplantation, 4 days before transplantation, 5 days before transplantation, 6 days before transplantation, 1 and 2 days before transplantation, 2 and 3 days before transplantation, 3 and 4 days before transplantation, 4 and 5 days before transplantation, 1 and 2 and 3 days before transplantation, 2 and 3 and 4 days before transplantation, 3 and 4 and 5 days before transplantation, or 3 days before transplantation and 4 and 5 and 6 days before transplantation.In certain embodiments, cyclophosphamide can be administered to the recipient 5 and 4 days before transplantation, and fludarabine can be administered to the recipient 3, 4, 5 and 6 days before transplantation.In certain embodiments, fludarabine can be administered to the recipient 2, 3 and 4 days before transplantation. In certain embodiments, cyclophosphamide may be administered to the recipient 5 and 6 days prior to transplant, and fludarabine may be administered to the recipient 2, 3, and 4 days prior to transplant. In certain embodiments, cyclophosphamide may be administered to the recipient 3 days prior to transplant, and fludarabine may be administered to the recipient 2, 3, and 4 days prior to transplant.

[0158] In certain embodiments, fludarabine is administered at about, at least about, or up to about 5 mg / m 2 / dose, 6mg / m 2 / dose, 7mg / m 2 / dose, 8mg / m 2 / dose, 9mg / m 2 / dose, 10mg / m 2 / dose, 11mg / m 2 / dose, 12mg / m 2 / dose, 13mg / m 2 / dose, 14mg / m 2 / dose, 15mg / m 2 / dose, 20mg / m 2 / dose, 21mg / m 2 / dose, 22mg / m 2 / dose, 23mg / m 2 / dose, 24mg / m 2 / dose, 25mg / m 2 / dose, 26mg / m 2 / dose, 27mg / m 2 / dose, 28mg / m2 / dose, 29mg / m 2 / dose, 30mg / m 2 / dose, 31mg / m 2 / dose, 32mg / m 2 / dose, 33mg / m 2 / dose, 34mg / m 2 / dose, 35mg / m 2 / dose, 40mg / m 2 / dose, 45mg / m 2 / dose, or 50 mg / m 2 In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about 10 mg / m 2 In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about, at least about, or up to about 5-15 mg / m 2 / dose, 10~15mg / m 2 / dose, 20~30mg / m 2 / dose, 25~35mg / m 2 / dose, 30~40mg / m 2 / dose, 35~45mg / m 2 / dose, or 40-50 mg / m 2 Fludarabine may be administered to the transplant recipient at a dose ranging from about, at least about, or up to about 24 mg / m 2 In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about 10 mg / m 2 In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about 24 mg / m2, and cyclophosphamide may be administered in the range of 5-15 mg / kg / dose, 10-20 mg / kg / dose, 15-25 mg / kg / dose, 20-30 mg / kg / dose, or 25-35 mg / kg / dose. 2 In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about 24 mg / m2, and cyclophosphamide may be administered in the range of 5-15 mg / kg / dose, 10-20 mg / kg / dose, 15-25 mg / kg / dose, 20-30 mg / kg / dose, or 25-35 mg / kg / dose. 2 / dose and cyclophosphamide may be administered to the transplant recipient at a dose of 14.5 mg / kg / dose.

[0159] In certain embodiments, fludarabine may be administered to a transplant recipient at a dose of 5 mg / sqm, 10 mg / sqm, 15 mg / sqm, 20 mg / sqm, 21 mg / sqm, 22 mg / sqm, 23 mg / sqm, 24 mg / sqm, 25 mg / sqm, 26 mg / sqm, 27 mg / sqm, 28 mg / sqm, 29 mg / sqm, 30 mg / sqm, 31 mg / sqm, 32 mg / sqm, 33 mg / sqm, 34 mg / sqm, 35 mg / sqm, 40 mg / sqm, 45 mg / sqm, or 50 mg / sqm. In certain embodiments, fludarabine may be administered to the transplant recipient at a dose ranging from about, at least about, or up to about 5-15 mg / sqm, 10-15 mg / sqm, 20-30 mg / sqm, 25-35 mg / sqm, 30-40 mg / sqm, 35-45 mg / sqm, or 40-50 mg / sqm. In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about 10 mg / sqm. In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about, at least about, or up to about 30 mg / sqm. In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of about 10 mg / sqm and cyclophosphamide may be administered in the range of 15-25 mg / kg / dose, 20-25 mg / kg / dose, 20-30 mg / kg / dose, 40-50 mg / kg / dose, 45-55 mg / kg / dose, 50-60 mg / kg / dose, or 55-65 mg / kg / dose. In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of 30 mg / sqm and cyclophosphamide may be administered in the range of 15-25 mg / kg / dose, 20-25 mg / kg / dose, 20-30 mg / kg / dose, 40-50 mg / kg / dose, 45-55 mg / kg / dose, 50-60 mg / kg / dose, or 55-65 mg / kg / dose. In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of 10 mg / sqm and cyclophosphamide may be administered at a dose of 22.5 mg / kg / dose. In certain embodiments, fludarabine may be administered to the transplant recipient at a dose of 30 mg / sqm and cyclophosphamide may be administered at a dose of 50 mg / kg / dose.

[0160] In certain embodiments, fludarabine can be administered to transplant recipients by any convenient method known in the art, including subcutaneous, intravenous, intravascular, topical, intraarterial, intracranial, intramuscular, oral, intraorbital, by inhalation, transdermal, intraperitoneal, or any other administration route that allows appropriate activation of fludarabine by recipients.In certain embodiments, fludarabine is administered intravenously.In certain embodiments, fludarabine is administered orally.

[0161] 5.3.6 Thymus irradiation In certain embodiments, the conditioning regimen provided herein includes the recipient receiving thymic irradiation prior to transplant surgery. In some embodiments, thymic irradiation may be administered 1 day, 2 days, more than 2 days, or 1 and 2 days prior to transplant surgery. In certain embodiments, the dose of thymic irradiation is sufficient to deplete intrathymic T cells. In certain embodiments, the dose of thymic irradiation may be 100 to 1000 cGy (centigray). In certain embodiments, the dose of thymic irradiation is about, at least about, or up to about 100 cGy, 200 cGy, 300 cGy, 400 cGy, 500 cGy, 600 cGy, 700 cGy, 800 cGy, 900 cGy, or 1000 cGy. In certain embodiments, the dose of thymic irradiation is about, at least about, or up to about 7 Gy. In certain embodiments, the recipient can receive about 7 Gy of thymic irradiation prior to same-day transplant surgery. In certain embodiments, the recipient can receive about 700 cGy of thymic irradiation prior to same-day transplant surgery. In certain embodiments, the timing and dose of thymic irradiation can be modified as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0162] 5.3.7 Total body irradiation In certain embodiments, the conditioning regimen provided herein includes the recipient receiving total body irradiation prior to transplantation surgery. In some embodiments, total body irradiation may be administered 3 days prior to transplantation, 4 days prior to transplantation, 5 days prior to transplantation, 6 days prior to transplantation, 7 days prior to transplantation, 3 and 4 days prior to transplantation, 3 and 5 days prior to transplantation, 4 and 5 days prior to transplantation, 4 and 6 days prior to transplantation, 5 and 6 days prior to transplantation, 5 and 7 days prior to transplantation, or 6 and 7 days prior to transplantation. In certain embodiments, the dose of total body irradiation may be 0.5-2.5 Gy. In certain embodiments, the dose of total body irradiation may be about, at least about, or up to about 0.5 Gy, 0.75 Gy, 1.0 Gy, 1.25 Gy, 1.50 Gy, 1.75 Gy, 2.0 Gy, 2.25 Gy, 2.50 Gy, 0.5-1.5 Gy, 0.75-1.25 Gy, 1.0-2.0 Gy, 1.25-2.25 Gy, or 1.50-2.50 Gy. In certain embodiments, the recipient may receive total body irradiation once per day. In certain embodiments, the recipient may receive total body irradiation twice per day. In certain embodiments, the recipient may receive 1.5 Gy of total body irradiation twice per day, 5 days and 4 days prior to transplant surgery. In certain embodiments, the recipient may receive 1.5 Gy of total body irradiation twice per day, 6 days and 5 days prior to transplant surgery. In certain embodiments, the timing and dose of total body irradiation may be modified as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0163] 5.3.8 Tacrolimus Tacrolimus, as used herein, is a macrolide antibiotic administered to a recipient to suppress the immune system. Tacrolimus has a similar mode of action as CyA (a calcineurin inhibitor), and trade names for tacrolimus include Prograf®, Adport®, Advagraf®, Protopic®, Astagraf XL®, Modigraf®, and Envarsus XR®.

[0164] In certain embodiments, the conditioning regimen provided herein comprises administering tacrolimus to the transplant recipient. In certain embodiments, tacrolimus may be administered 1 day before transplantation, 2 days before transplantation, 3 days before transplantation, 1 and 2 days before transplantation, 1 and 3 days before transplantation, or 1, 2 and 3 days before transplantation. In certain embodiments, tacrolimus may be administered to the recipient 1 day before transplantation. In some embodiments, tacrolimus is administered on the same day as transplantation.

[0165] Tacrolimus may be included in a post-operative treatment regimen to suppress the immune system and inhibit the development of graft-versus-host disease in the recipient. The post-operative treatment regimen may include a constant course of tacrolimus administered to the recipient, followed by a tapering course.

[0166] In certain embodiments, the post-operative treatment regimens provided herein comprise administering fludarabine to the transplant recipient. In certain embodiments, tacrolimus may be administered on the day of transplant, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, or 18 months after transplant surgery. In some embodiments, tacrolimus is administered to the subject after transplantation. In some embodiments, tacrolimus is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 20 months, 24 months, or more than 24 months after transplantation. In some embodiments, tacrolimus is administered about or at least about 1-2 months, 2-3 months, 3-4 months, 4-5 months, 5-6 months, 6-7 months, 7-8 months, 8-9 months, 9-10 months, 11-12 months, 1-6 months, 2-6 months, 3-6 months, 4-6 months, 6-12 months, or more than 6-12 months after transplantation. In some embodiments, tacrolimus is administered over a continuous period of time (e.g., from the day of transplantation until about 1 month, or about 9 months, or about 12 months after transplantation or initiation of treatment). In some embodiments, tacrolimus is administered in an amount of about 8-10 ng / ml. In some embodiments, tacrolimus is administered in an amount of about 4-11 ng / ml.

[0167] In certain embodiments, a single dose of tacrolimus may be administered. In certain embodiments, multiple doses of tacrolimus may be administered. In certain embodiments, a fixed dose of tacrolimus may be administered. In certain embodiments, a tapering course of tacrolimus may be administered. In certain embodiments, a fixed dose of tacrolimus followed by a tapering course of tacrolimus may be administered postoperatively.

[0168] In certain embodiments, tacrolimus may be administered to the transplant recipient at a frequency of once a day or twice a day. In certain embodiments, tacrolimus may be administered twice a day at a dose of about, at least about, or up to about 0.01 mg / kg / dose, 0.02 mg / kg / dose, 0.03 mg / kg / dose, 0.04 mg / kg / dose, 0.05 mg / kg / dose, 0.06 mg / kg / dose, 0.07 mg / kg / dose, 0.08 mg / kg / dose, 0.09 mg / kg / dose, 0.1 mg / kg / dose, 0.01-0.05 mg / g / dose, 0.05-0.1 mg / kg / dose, 0.02-0.06 mg / kg / dose, 0.03-0.07 mg / kg / dose, 0.04-0.08 mg / kg / dose, or 0.01-0.1 mg / kg / dose. In certain embodiments, tacrolimus may be administered to a transplant recipient at a dose of 0.05 mg / kg / dose twice daily.

[0169] In certain embodiments, tacrolimus may be administered postoperatively to the recipient at a dose sufficient to obtain a target trough blood level of 1-5 ng / ml, 5-10 ng / ml, 8-10 ng / ml, 4-11 ng / ml, 10-15 ng / ml, 1-11 ng / ml, 2-12 ng / ml, 3-13 ng / ml, 4-14 ng / ml, 5-15 ng / ml, 6-16 ng / ml, 7-17 ng / ml, 8-18 ng / ml, 9-19 ng / ml, 10-20 ng / ml, or 15-20 ng / ml. In certain embodiments, the target trough blood level may be 10-15 ng / ml.

[0170] In some embodiments, tacrolimus is administered to a subject at a dose of about, at least about, or up to about 1-5 ng / ml, 5-10 ng / ml, 8-10 ng / ml, 4-11 ng / ml, 10-15 ng / ml, 1-11 ng / ml, 2-12 ng / ml, 3-13 ng / ml, 4-14 ng / ml, 5-15 ng / ml, 6-16 ng / ml, 7-17 ng / ml, 8-18 ng / ml, 9-19 ng / ml, 10-20 ng / ml, or 15-20 ng / ml. In some embodiments, tacrolimus is administered to a subject at a dose of about, at least about, or up to about 1 ng / ml, 2 ng / ml, 3 ng / ml, 4 ng / ml, 5 ng / ml, 6 ng / ml, 7 ng / ml, 8 ng / ml, 9 ng / ml, 10 ng / ml, 11 ng / ml, 12 ng / ml, 13 ng / ml, 14 ng / ml, 15 ng / ml, 16 ng / ml, 17 ng / ml, 18 ng / ml, 19 ng / ml, 20 ng / ml, 22 ng / ml, 25 ng / ml, 30 ng / ml, or greater than 30 ng / ml.

[0171] In certain embodiments, tacrolimus can be administered to transplant recipients at a constant dose.The period during which the constant dose is administered can be 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 60 days, 90 days, 120 days, 150 days, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation.In certain embodiments, tacrolimus administered to transplant recipients can be tapered to discontinue. In certain embodiments, this tapering course may occur over 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, or 18 months after transplantation.

[0172] In certain embodiments, tacrolimus may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, or intraperitoneally, or any route of administration that allows for adequate activity of tacrolimus by the recipient. In certain embodiments, tacrolimus may be administered orally. In certain embodiments, tacrolimus may be administered intravenously. In certain embodiments, administration of tacrolimus may be modified as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0173] In certain embodiments, potential equivalents of tacrolimus may be substituted in postoperative treatment regimens. These alternatives include cyclosporine (Gengraf®, Neoral®, and Sandimmune®), belatacept (Nulojix), sirolimus, and everolimus. In certain embodiments, belatacept may be used to suppress the immune system in the recipient.

[0174] In certain embodiments, the postoperative treatment regimen provided herein comprises administering belatacept to the transplant recipient.In certain embodiments, belatacept is administered on the day of transplantation, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 28 days, 29 days, 30 days, 31 days, 32 days, 33 days, 34 days, 35 days, 36 days, 37 days, 38 days, 39 days, 40 days, 41 days, 42 days, 43 days, 44 days, 45 days, 46 days, 47 days, 48 ​​days, 49 days, 50 days, 51 days, 52 days, 53 days, 54 days, 55 days, 56 days, 57 days, 58 days, 59 days, 60 days, 61 days, 62 days, 63 days, 64 days, 65 days, 66 days, 67 days, 68 days, 69 days, 70 days, 71 days, 72 days, 73 days, 74 days, 75 days, 76 days, 77 days, 78 days, 79 days, 80 days, 81 days, 82 days, 83 days, 84 days, 85 days, 86 days, 87 days, 88 days, 89 days, 90 days, 91 days, 92 days, 93 days, 94 days, 95 days, 96 days, 97 days The belatacept may be administered 27 days, 28 days, 29 days, 30 days, 31 days, 32 days, 33 days, 34 days, 35 days, 36 days, 37 days, 38 days, 39 days, 40 days, 60 days, 90 days, 120 days, 150 days, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In certain embodiments, the belatacept may be administered a single time. In certain embodiments, the belatacept may be administered multiple times. In certain embodiments, the belatacept may be administered five times after transplantation surgery. In certain embodiments, the belatacept may be administered one day after transplantation surgery. In certain embodiments, the belatacept may be administered five days after transplantation surgery. In certain embodiments, the belatacept may be administered 12 days after transplantation surgery. In certain embodiments, belatacept may be administered 19 days after transplant surgery. In certain embodiments, belatacept may be administered 33 days after transplant surgery. In certain embodiments, belatacept may be administered 1 day, 5 days, 12 days, 19 days, and 33 days after transplant surgery.

[0175] In certain embodiments, belatacept or tacrolimus is administered at about, at least about, or up to about 2 mg / kg / day, 2.5 mg / kg / day, 3 mg / kg / day, 3.5 mg / kg / day, 4 mg / kg / day, 4.5 mg / kg / day, 5 mg / kg / day, 5.5 mg / kg / day, 6 mg / kg / day, 6.5 mg / kg / day, 7 mg / kg / day, 7.5 mg / kg / day, 8 mg / kg / day, 8.5 mg / kg / day, 9 mg / kg / day, 9.5 mg / kg / day, 10 mg / kg / day, 10.5 mg / kg / day, 11 mg / kg / day, 11.5 mg / kg / day, 12 mg / kg / day, 12.5 mg / kg / day, 13 mg / kg / day, 13.5 mg / kg / day, 14 mg / kg / day, 15 mg / kg / day, 16 mg / kg / day, 17 mg / kg / day, 18 mg / kg / day, 19 mg / kg / day, 20 mg / kg / day, 21 mg / kg / day, 22 mg / kg / day, 23 mg / kg / day, 24 mg / kg / day, 25 mg / kg / day, 26 mg / kg / day, 27 mg / kg / day, 28 mg / kg / day, 29 mg / kg / day, 30 mg / kg / day, 31 mg / kg / day, 32 mg / kg / day, 33 mg / kg / day, 34 mg / kg / day, 35 mg / kg / day, 36 mg / kg / day, 37 mg / kg / day, 38 mg / kg / day, 39 mg / kg / day, 40 mg / kg / day, 41 mg / kg / day, 42 mg / kg / day g / kg / day, 14 mg / kg / day, 14.5 mg / kg / day, 15 mg / kg / day, 15.5 mg / kg / day, 16 mg / kg / day, 16.5 mg / kg / day, 17 mg / kg / day, 17.5 mg / kg / day, 18 mg / kg / day, 2-6 mg / kg / day, 3-7 mg / kg / day, 4-8 mg / kg / day, 5-9 mg / kg / day, 6-10 mg / kg / day, 7-11 mg / kg / day, 8-12 mg / kg / day, 9-13 mg / kg / day, 10-14 mg / kg / day, 11-15 mg / kg / day, 12-16 mg / kg / day, 13-17 mg / kg / day, or 14-18 mg / kg / day. In certain embodiments, belatacept or tacrolimus may be administered to the transplant recipient at a dose of 10 mg / kg / day.

[0176] In certain embodiments, a single dose of tacrolimus may be administered. In certain embodiments, multiple doses of tacrolimus may be administered. In certain embodiments, a fixed dose of tacrolimus may be administered. In certain embodiments, a tapering course of tacrolimus may be administered. In certain embodiments, a fixed dose of tacrolimus may be administered followed by a tapering course of tacrolimus.

[0177] In certain embodiments, tacrolimus may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, or intraperitoneally, or any route of administration that allows for adequate activity of tacrolimus by the recipient. In certain embodiments, tacrolimus may be administered orally. In certain embodiments, tacrolimus may be administered intravenously. In certain embodiments, administration of tacrolimus may be modified as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0178] In certain embodiments, the conditioning regimens provided herein include administering tacrolimus to the transplant recipient prior to transplantation and / or cell infusion. In some embodiments, tacrolimus is administered to the recipient 1 day prior to transplantation and / or cell infusion, 2 days prior to transplantation and / or cell infusion, 3 days prior to transplantation and / or cell infusion, 4 days prior to transplantation and / or cell infusion, 5 days prior to transplantation and / or cell infusion, 6 days prior to transplantation and / or cell infusion, 7 days prior to transplantation and / or cell infusion, 8 days prior to transplantation and / or cell infusion, 9 days prior to transplantation and / or cell infusion, 10 days prior to transplantation and / or cell infusion, or more than 10 days prior to transplantation and / or cell infusion. In some embodiments, tacrolimus is administered to the recipient 1 day after transplantation and / or cell infusion, 2 days after transplantation and / or cell infusion, 3 days after transplantation and / or cell infusion, 4 days after transplantation and / or cell infusion, 5 days after transplantation and / or cell infusion, 6 days after transplantation and / or cell infusion, 7 days after transplantation and / or cell infusion, 8 days after transplantation and / or cell infusion, 9 days after transplantation and / or cell infusion, 10 days after transplantation and / or cell infusion, 11 days after transplantation and / or cell infusion, 12 days after transplantation and / or cell infusion, or more than 12 days after transplantation and / or cell infusion. In some embodiments, tacrolimus is administered to the recipient on the same day as transplantation and / or cell infusion (e.g., a period of time thereafter (e.g., 1 month, or 9-12 months)). In some embodiments, tacrolimus is administered to the recipient about, at least about, or up to about 1 time (or 1 day), 2 times (or 2 different days), 3 times (or 3 different days), 4 times (or 4 different days), 5 times (or 5 different days), 6 times (or 6 different days), 7 times (or 7 different days), 8 times (or 8 different days), 9 times (or 9 different days), 10 times (or 10 different days), or more than 10 times (or more than 10 different days) prior to transplantation and / or cell infusion.In some embodiments, tacrolimus is administered to the recipient about, at least about, or up to about 1 time (or 1 day), 2 times (or 2 different days), 3 times (or 3 different days), 4 times (or 4 different days), 5 times (or 5 different days), 6 times (or 6 different days), 7 times (or 7 different days), 8 times (or 8 different days), 9 times (or 9 different days), 10 times (or 10 different days), or more than 10 times (or more than 10 different days) after transplantation and / or cell infusion. In some embodiments, tacrolimus is administered to the recipient about 1 day, 10 days, 15 days, 20 days, 25 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, when tacrolimus is administered to a transplant recipient more than once or on more than one day, the dosage is the same on all days and / or the same per administration. In some embodiments, when tacrolimus is administered to a transplant recipient more than once or on more than one day, the dosage is not the same on all days and / or the same per administration. In certain embodiments, the dose of tacrolimus administered to a recipient in a postoperative regimen is the same as the dose administered in a conditioning regimen. In certain embodiments, the dose of tacrolimus administered to a recipient in a postoperative regimen is different from the dose administered in a conditioning regimen. In some embodiments, tacrolimus is administered prophylactically.

[0179] In certain embodiments, the postoperative treatment regimen provided herein comprises administering tacrolimus to the transplant recipient. In some embodiments, one dose of tacrolimus can be administered postoperatively. In some embodiments, two doses of tacrolimus can be administered postoperatively. In some embodiments, more than two doses of tacrolimus can be administered postoperatively.

[0180] 5.3.9 Anti-IL6R antibody In certain embodiments, the methods described herein may include therapeutic blockade of IL-6 cytokine signaling. In certain embodiments, IL-6 signaling may be blocked by targeting IL-6. In certain embodiments, IL-6 signaling may be blocked by targeting IL6R. In certain embodiments, IL6R may be targeted by a small molecule inhibitor (Hong et al., Immunol. 2015, 195(1)237-245). In certain embodiments, IL6R may be targeted by an antibody. In certain embodiments, the anti-IL6R therapy may be a humanized monoclonal antibody. In certain embodiments, the anti-IL6R receptor may be tocilizumab. In certain embodiments, the therapy may be administered to the transplant recipient to reduce acute kidney injury (AKI, also known as engraftment syndrome) while likely simultaneously further increasing Treg levels.

[0181] In certain embodiments, an anti-IL6R antibody for use with the methods and compositions of the invention comprises heavy chain CDR1, 2, or 3 of tocilizumab. In certain embodiments, an anti-IL6R antibody for use with the methods and compositions of the invention comprises light chain CDR1, 2, or 3 of tocilizumab. In certain embodiments, an anti-IL6R antibody for use with the methods and compositions of the invention comprises one, two, three, four, five, or all six CDRs of tocilizumab. [Table 6]

[0182] In particular embodiments, an anti-IL6R antibody for use with the methods and compositions of the invention comprises one, two, three, four, five or all six CDRs set forth in Table 6. In certain embodiments, one, two, three, four, five or all six have one, two, three, four, five, six, seven, eight, nine or ten amino acid substitutions. In certain more particular embodiments, such amino acid substitutions are conservative amino acid substitutions.

[0183] In certain embodiments, an anti-IL6R antibody for use with the methods and compositions provided herein has a heavy chain variable region comprising an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98%, at least 99% or 100% identical to SEQ ID NO: 28. In certain embodiments, an anti-IL6R antibody for use with the methods and compositions provided herein has a light chain variable region comprising an amino acid sequence that is about or at least about 80%, 85%, 90%, 95%, 98%, at least 99% or 100% identical to SEQ ID NO: 29.

[0184] In certain embodiments, the anti-IL6R antibody immunospecifically binds to the same epitope in human IL6R as tocilizumab.

[0185] In certain embodiments, the anti-IL6R antibody may be an animal-specific antibody, a human-specific antibody, a chimeric antibody, a humanized antibody, a full-length antibody, an antibody fragment, a single-chain variable fragment (scFv), a naturally occurring antibody, a synthetic antibody, an engineered antibody, or a combination thereof. In certain embodiments, the anti-IL6R antibody may be a humanized anti-IL6R monoclonal antibody.

[0186] In certain embodiments, the postoperative treatment regimen provided herein comprises administering an anti-IL6R antibody or tocilizumab to a transplant recipient. In certain embodiments, the anti-IL6R antibody or tocilizumab is administered on the day of transplantation, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 7 and 14 days, the day and 1 day, the day and 1 day and 2 days ... and 4 and 5 days, 4 and 5 and 6 days, 5 and 6 and 7 days, 6 and 7 and 8 days, 7 and 8 and 9 days, 8 and 9 and 10 days, 9 and 10 and 11 days, 10 and 11 and 12 days, 12 and 13 and 14 days, 13 and 14 and 15 days, 8 and 9 and 10 days, 8 and 9 and 10 days, 16 and 17 and 18 days, 17 and 18 and 19 days, or 18 and 19 and 20 days. In some embodiments, the anti-IL6R antibody or tocilizumab is administered to the subject after transplantation. In some embodiments, the anti-IL6R antibody or tocilizumab is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 20 months, 24 months, or more than 24 months after transplantation. In some embodiments, the anti-IL6R antibody or tocilizumab is administered about or at least about 1-2 months, 2-3 months, 3-4 months, 4-5 months, 5-6 months, 6-7 months, 7-8 months, 8-9 months, 9-10 months, 11-12 months, 1-6 months, 2-6 months, 3-6 months, 4-6 months, 6-12 months, or more than 6-12 months after transplantation.

[0187] In certain embodiments, the method further comprises administering tocilizumab to the patient after transplantation.In certain embodiments, if the patient shows early post-transplant chimera transition syndrome (CTS), tocilizumab can be administered.In certain embodiments, if CTS occurs, tocilizumab can be administered to the subject.In certain embodiments, tocilizumab is administered to the subject at a dose of about 8mg / kg.

[0188] In certain embodiments, tocilizumab is administered at about, at least about, or up to about 2.0 mg / kg / dose, 3.0 mg / kg / dose, 4.0 mg / kg / dose, 5.0 mg / kg / dose, 6.0 mg / kg / dose, 6.25 mg / kg / dose, 6.5 mg / kg / dose, 6.75 mg / kg / dose, 7.0 mg / kg / dose, 7.25 mg / kg / dose, 7.5 mg / kg / dose, 7.75 mg / kg / dose, 8.0 mg / kg / dose , 8.25mg / kg / dose, 8.5mg / kg / dose, 8.75mg / kg / dose, 9.0mg / kg / dose, 9.25mg / kg / dose, 9.5mg / kg / dose, 9.75mg / kg / dose, 10.0mg / kg / dose, 10.25mg / kg / dose, 10.5mg / kg / dose, 10.75mg / kg / dose, 11.0mg / kg / dose, 11.25mg / kg / dose, 11.5mg / kg / dose, 11.75mg / kg / dose, 12.0mg / kg / dose, 12.25mg / kg / dose, 12.5mg / kg / dose, 12.75mg / kg / dose, 13.0mg / kg / dose, 14.0mg / kg / dose, 15.0mg / kg / dose , 16.0mg / kg / dose, 17.0mg / kg / dose, 18.0mg / kg / dose, 6.0~10.0mg / kg / dose, 6.25~10.25mg / kg / dose, 6.5~10.5mg / kg / dose, 6.7 Tocilizumab may be administered to a patient at a dose of 5-10.75 mg / kg / dose, 7.0-11.0 mg / kg / dose, 7.25-11.25 mg / kg / dose, 7.5-11.5 mg / kg / dose, 7.75-11.75 mg / kg / dose, 8.0-12.0 mg / kg / dose, 8.25-12.25 mg / kg / dose, 8.5-12.5 mg / kg / dose, 8.75-12.75 mg / kg / dose, or 9.0-13.0 mg / kg / dose. In certain embodiments, tocilizumab may be administered to a patient at a dose of 8.0 mg / kg / dose. In certain embodiments, tocilizumab may be administered to a patient at a dose of 12.0 mg / kg / dose. In certain embodiments, if the patient has a body weight greater than 30 mg / kg, tocilizumab is administered at a concentration of 8.0 mg / kg. In certain embodiments, if the patient has a body weight less than 30 mg / kg, tocilizumab is administered at a concentration of 12.0 mg / kg.In certain embodiments, tocilizumab will be administered over a 1 hour period, with at least 8 hours between doses, for a total of up to 4 doses (if response to the first dose is inadequate).

[0189] In certain embodiments, tocilizumab may be administered if the patient presents with early post-transplant acute kidney injury (AKI). In certain embodiments, creatinine levels may be used to determine AKI. In certain embodiments, tocilizumab may be administered alone. In certain embodiments, tocilizumab may be administered in combination with corticosteroids. If insufficient clinical improvement in signs and symptoms of AKI occurs after the first administration, an additional dose of tocilizumab may be administered. In some embodiments, the patient may be administered one additional dose of tocilizumab, two additional doses of tocilizumab, or three additional doses of tocilizumab. When additional doses of tocilizumab are administered, in certain embodiments, at least 8 hours must elapse between successive doses.

[0190] In some embodiments, the patient may be administered one dose of tocilizumab daily. In some embodiments, the patient may be administered multiple doses of tocilizumab daily. In some embodiments, the patient may be administered one dose of tocilizumab. In some embodiments, the patient may be administered two doses of tocilizumab. In some embodiments, the patient may be administered three doses of tocilizumab. In some embodiments, the patient may be administered four doses of tocilizumab. In certain embodiments, one dose of tocilizumab is administered, followed by additional doses until the clinical signs and symptoms of AKI improve.

[0191] In certain embodiments, tocilizumab may be administered intravenously or subcutaneously.

[0192] In certain embodiments, alternative antagonists of IL6 signaling may be administered. In certain embodiments, these alternative antagonists of IL6 signaling may include, but are not limited to, soluble gp130, CS-IVa-Be, bazedoxifene, and LMT-28. In certain embodiments, alternative antagonists of IL6 signaling may be administered to patients after transplantation. In certain embodiments, alternative antagonists of IL6 signaling may be administered when patients present with early post-transplant acute kidney injury (AKI).

[0193] In certain embodiments, the anti-IL-6 therapy may be an anti-IL6R, such as, but not limited to, ACTEMRA®, RoActemra®, sarilumab, and ALX-0061. In certain embodiments, the anti-IL-6 therapy may be an anti-IL6 mAb, such as, but not limited to, siltuximab, sirumab, clazakizumab, MEDI5117, and olokizumab.

[0194] 5.3.10 Steroids Steroids, as used herein, are compounds administered to organ transplant recipients to suppress the immune system. Prednisone is a corticosteroid, chemical name 17,21-dihydroxypregna-1,4-dienyl-3,11,20-trione (C 21 H 26 O5). Trade names for prednisone include, but are not limited to, Deltasone®, Sterapred®, Rayos®, Prednicot®, and Meticorten®. In some embodiments, the steroid is a corticosteroid.

[0195] In certain embodiments, the postoperative treatment regimen provided herein comprises administering steroids to transplant recipients.In certain embodiments, steroids can be administered on the day of transplantation, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, or 30 days after transplantation. In some embodiments, the steroid can be administered to the recipient for about 10 days, 15 days, 20 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, the steroid is administered to the subject after transplantation. In some embodiments, the steroid is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 20 months, 24 months, or more than 24 months after transplantation. In some embodiments, the steroid is administered about or at least about 1-2 months, 2-3 months, 3-4 months, 4-5 months, 5-6 months, 6-7 months, 7-8 months, 8-9 months, 9-10 months, 11-12 months, 1-6 months, 2-6 months, 3-6 months, 4-6 months, 6-12 months, or more than 6-12 months after transplantation.

[0196] In certain embodiments, the steroid may be administered from the day of transplant surgery until 5 days after surgery, from the day of transplant surgery until 10 days after surgery, from the day of transplant surgery until 15 days after surgery, from the day of transplant surgery until 20 days after surgery, from the day of transplant surgery until 25 days after surgery, or from the day of transplant surgery until 30 days after surgery, from the day of transplant surgery until 6 months after surgery.

[0197] In certain embodiments, a single dose of steroid may be administered. In certain embodiments, multiple doses of steroid may be administered. In certain embodiments, a flat dose of steroid may be administered. In certain embodiments, a steroid pulse may be administered. In certain embodiments, a tapering course of steroid may be administered. In certain embodiments, a flat dose of steroid may be administered followed by a tapering course of steroid. In certain embodiments, a flat dose of steroid with a steroid pulse may be administered followed by a tapering course of steroid.

[0198] In certain embodiments, the steroid may be administered to the transplant recipient at a dose of about, at least about, or at most about 0.1 mg / kg, 0.2 mg / kg, 0.3 mg / kg, 0.4 mg / kg, 0.5 mg / kg, 0.6 mg / kg, 0.7 mg / kg, 0.8 mg / kg, 0.9 mg / kg, 1.0 mg / kg, 1.1 mg / kg, 1.2 mg / kg, 1.3 mg / kg, 1.4 mg / kg, 1.5 mg / kg, 1.6 mg / kg, 1.7 mg / kg, 1.8 mg / kg, 1.9 mg / kg, 2.0 mg / kg, 2.1 mg / kg, 2.2 mg / kg, 2.3 mg / kg, 2.4 mg / kg, 2.5 mg / kg, 2.6 mg / kg, 2.7 mg / kg, 2.8 mg / kg, 2.9 mg / kg, or 3.0 mg / kg. In certain embodiments, steroids may be administered to the transplant recipient at a dose of 2 mg / kg.

[0199] In certain embodiments, the steroid is administered to the transplant recipient in a pulse dose of 100 mg / dose, 200 mg / dose, 250 mg / dose, 300 mg / dose, 400 mg / dose, 500 mg / dose, 600 mg / dose, 700 mg / dose, 800 mg / dose, 900 mg / dose, or 1000 mg / dose. In certain embodiments, the steroid may be administered to the transplant recipient in a dose of about 250 mg / dose. In certain embodiments, the steroid may be administered in a pulse dose of 500 mg / dose. In certain embodiments, the steroid pulse can be administered on the day of transplantation, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, on the day of transplantation and for about 20 days, on the day of transplantation and for about 6 months, on the day of transplantation and 1 day and 2 days, 3 days and 4 days and 5 days, 6 days and 7 days and 8 days, 9 days and 10 days and 11 days, 10 days and 11 days and 12 days, 11 days and 12 days and 13 days, or 13 days and 14 days and 15 days. In certain embodiments, the steroid pulse is administered on the day of transplantation. In certain embodiments, the steroid pulse is administered 10 days and 11 days and 12 days after transplantation.

[0200] In certain embodiments, steroids can be administered to transplant recipients at a constant dose.The period during which the constant dose is administered can be 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 15 days, 20 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, or more than 9 months.In certain embodiments, the steroids administered to transplant recipients can be tapered to stop. In certain embodiments, the tapering course can be carried out for 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, or more than 9 months.In certain embodiments, the tapering course can be carried out for 10 days.In certain embodiments, the tapering course can be carried out for 20 days.In certain embodiments, the tapering course can be carried out for 6 days or months.

[0201] In certain embodiments, for a tapering course, the steroid administered to the recipient is about, at least about, or up to about 0.01 mg / kg per day, 0.02 mg / kg per day, 0.03 mg / kg per day, 0.04 mg / kg per day, 0.05 mg / kg per day, 0.06 mg / kg per day, 0.07 mg / kg per day, 0.08 mg / kg per day, 0.09 mg / kg per day, 0.1 mg / kg per day, 0.2 mg / kg per day, 0.3 mg / kg per day, 0.4 mg / kg per day, 0.5 mg / kg per day, 0.6 mg / kg per day, 0.7 mg / kg per day, 0.8 mg / kg per day, 0. ...8 mg / kg per day, 0.9 mg / kg per day, 0.1 The dose may be reduced by 0.5 mg / kg per day, 0.6 mg / kg per day, 0.7 mg / kg per day, 0.8 mg / kg per day, 0.9 mg / kg per day, 1.0 mg / kg per day, 1.1 mg / kg per day, 1.2 mg / kg per day, 1.3 mg / kg per day, 1.4 mg / kg per day, 1.5 mg / kg per day, 1.6 mg / kg per day, 1.7 mg / kg per day, 1.8 mg / kg per day, 1.9 mg / kg per day, 2.0 mg / kg per day, or by more than 2.0 mg / kg per day.

[0202] In certain embodiments, the steroid may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, or intraperitoneally, or any route of administration that allows for adequate activity of the steroid by the recipient. In certain embodiments, the steroid may be administered orally. In certain embodiments, the steroid may be administered intravenously.

[0203] In certain embodiments, the steroid administered in the postoperative treatment regimen can be prednisone. In certain embodiments, the pulse steroid administered in the postoperative treatment regimen can be methylprednisone. In certain embodiments, the administration of steroids can be altered as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0204] 5.3.11 Cyclosporine Cyclosporine A (CyA), as used herein, is a compound administered to a recipient to suppress the immune system, with a specific effect on T cells. 62 H 111 N 11 O 12 CyA can be administered to transplant recipients to inhibit the development of graft-versus-host disease. Trade names for CyA include Gengraf®, Neoral®, and Sandimmune®.

[0205] In certain embodiments, the conditioning regimen provided herein comprises administering CyA to the transplant recipient. In certain embodiments, CyA can be administered 1 day before transplantation, 2 days before transplantation, 3 days before transplantation, 1 and 2 days before transplantation, 1 and 3 days before transplantation, or 1, 2 and 3 days before transplantation. In certain embodiments, CyA can be administered to the recipient 1 day before transplantation.

[0206] Cyclosporine (CyA) may be included in the postoperative treatment regimen to suppress the immune system and inhibit the development of graft-versus-host disease in the recipient. The postoperative treatment regimen may include a constant course of CyA administered to the recipient, followed by a tapering course.

[0207] In certain embodiments, the post-operative treatment regimens provided herein comprise administering CyA to the transplant recipient. In certain embodiments, CyA may be administered on the day of transplant, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, or 18 months after transplant surgery. In some embodiments, CyA is administered to the subject after transplantation. In some embodiments, CyA is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 20 months, 24 months, or more than 24 months after transplantation. In some embodiments, CyA is administered about or at least about 1-2 months, 2-3 months, 3-4 months, 4-5 months, 5-6 months, 6-7 months, 7-8 months, 8-9 months, 9-10 months, 11-12 months, 1-6 months, 2-6 months, 3-6 months, 4-6 months, 6-12 months, or more than 6-12 months after transplantation.

[0208] In certain embodiments, a single dose of CyA may be administered. In certain embodiments, multiple doses of CyA may be administered. In certain embodiments, a fixed dose of CyA may be administered. In certain embodiments, a tapering course of CyA may be administered. In certain embodiments, a fixed dose of CyA followed by a tapering course of CyA may be administered postoperatively.

[0209] In certain embodiments, CyA is administered at a dose of 2 mg / kg / day, 2.5 mg / kg / day, 3 mg / kg / day, 3.5 mg / kg / day, 4 mg / kg / day, 4.5 mg / kg / day, 5 mg / kg / day, 5.5 mg / kg / day, 6 mg / kg / day, 6.5 mg / kg / day, 7 mg / kg / day, 7.5 mg / kg / day, 8 mg / kg / day, 8.5 mg / kg / day, 9 mg / kg / day, 9.5 mg / kg / day, 10 mg / kg / day, 10.5 mg / kg / day, 11 mg / kg / day, 11.5 mg / kg / day, 12 mg / kg / day, 12.5 mg / kg / day, 13 mg / kg / day, 13.5 mg / kg / day, 14 mg / kg / day, 15 mg / kg / day, 16 mg / kg / day, 17 mg / kg / day, 18 mg / kg / day, 19 mg / kg / day, 20 mg / kg / day, 21 mg / kg / day, 22 mg / kg / day, 23 mg / kg / day, 24 mg / kg / day, 25 mg / kg / day, 26 mg / kg / day, 27 mg / kg / day, 28 mg / kg / day, 29 mg / kg / day, 30 mg / kg / day, 31 mg / kg / day, 32 mg / kg / day, 33 mg / kg / day, 34 mg / kg / day, 35 mg / kg / day, 36 mg / kg / day, 37 mg / kg / day, 38 mg / kg / day, 39 mg / kg / day, 40 mg / kg / day, 41 mg / kg / day, 42 mg / kg / day, 43 mg / kg / day, 44 mg / g / day, 14.5 mg / kg / day, 15 mg / kg / day, 15.5 mg / kg / day, 16 mg / kg / day, 16.5 mg / kg / day, 17 mg / kg / day, 17.5 mg / kg / day, 18 mg / kg / day, 2-6 mg / kg / day, 3-7 mg / kg / day, 4-8 mg / kg / day, 5-9 mg / kg / day, 6-10 mg / kg / day, 7-11 mg / kg / day, 8-12 mg / kg / day, 9-13 mg / kg / day, 10-14 mg / kg / day, 11-15 mg / kg / day, 12-16 mg / kg / day, 13-17 mg / kg / day, or 14-18 mg / kg / day. In certain embodiments, CyA may be administered to the transplant recipient at a dose of 8 mg / kg / day. In certain embodiments, CyA may be administered to the transplant recipient at a dose of 9 mg / kg / day. In certain embodiments, CyA may be administered to the transplant recipient at a dose of 10 mg / kg / day. In certain embodiments, CyA may be administered to the transplant recipient at a dose of 11 mg / kg / day. In certain embodiments, CyA may be administered to the transplant recipient at a dose of 12 mg / kg / day. In certain embodiments, CyA may be administered to the transplant recipient at a dose ranging from 8 to 12 mg / kg / day.

[0210] In certain embodiments, CyA may be administered postoperatively to the recipient in a dose sufficient to obtain a target trough blood level of 100-200ng / ml, 125-225ng / ml, 150-250ng / ml, 175-275ng / ml, 200-300ng / ml, 225-325ng / ml, 250-350ng / ml, 275-375ng / ml, 300-400ng / ml, 325-425ng / ml, 350-450ng / ml, 375-475ng / ml, or 400-500ng / ml. In certain embodiments, the target trough blood level may be 250-350ng / ml.

[0211] In certain embodiments, CyA can be administered to transplant recipients at a constant dose. The period during which the constant dose is administered can be 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, or 30 days after transplantation. In certain embodiments, CyA administered to transplant recipients can be tapered to stop. In certain embodiments, this tapering course can be carried out over 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, or 18 months after transplantation.

[0212] In certain embodiments, CyA may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, or intraperitoneally, or any route of administration that allows for adequate activity of CyA by the recipient. In certain embodiments, CyA may be administered orally. In certain embodiments, CyA may be administered intravenously. In certain embodiments, administration of CyA may be modified as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0213] In certain embodiments, replacement compounds may be used in place of CyA. These compounds may include tacrolimus (Prograf®, Adport®, Advagraf®, Envarsus®, Modigraf®, Astagraf®), belatacept (Nulojix®), sirolimus, and everolimus. In certain embodiments, belatacept may be used to suppress the immune system in the recipient.

[0214] In certain embodiments, the postoperative treatment regimen provided herein comprises administering belatacept to transplant recipient.In certain embodiments, belatacept can be administered on the day of transplantation, 1 day after transplantation, 2 days after, 3 days after, 4 days after, 5 days after, 6 days after, 7 days after, 8 days after, 9 days after, 10 days after, 11 days after, 12 days after, 13 days after, 14 days after, 15 days after, 16 days after, 17 days after, 18 days after, 19 days after, 20 days after, 21 days after, 22 days after, 23 days after, 24 days after, 25 days after, 26 days after, 27 days after, 28 days after, 29 days after, 30 days after, 31 days after, 32 days after, 33 days after, 34 days after, 35 days after, 36 days after, 37 days after, 38 days after, 39 days after, or 40 days after. In certain embodiments, belatacept may be administered once. In certain embodiments, belatacept may be administered multiple times. In certain embodiments, belatacept may be administered 5 times after transplantation surgery. In certain embodiments, belatacept may be administered 1 day after transplantation surgery. In certain embodiments, belatacept may be administered 5 days after transplantation surgery. In certain embodiments, belatacept may be administered 12 days after transplantation surgery. In certain embodiments, belatacept may be administered 19 days after transplantation surgery. In certain embodiments, belatacept may be administered 33 days after transplantation surgery. In certain embodiments, belatacept may be administered 1 day and 5 days and 12 days and 19 days and 33 days after transplantation surgery.

[0215] In certain embodiments, belatacept is administered at a dose of 2 mg / kg / day, 2.5 mg / kg / day, 3 mg / kg / day, 3.5 mg / kg / day, 4 mg / kg / day, 4.5 mg / kg / day, 5 mg / kg / day, 5.5 mg / kg / day, 6 mg / kg / day, 6.5 mg / kg / day, 7 mg / kg / day, 7.5 mg / kg / day, 8 mg / kg / day, 8.5 mg / kg / day, 9 mg / kg / day, 9.5 mg / kg / day, 10 mg / kg / day, 10.5 mg / kg / day, 11 mg / kg / day, 11.5 mg / kg / day, 12 mg / kg / day, 12.5 mg / kg / day, 13 mg / kg / day, 13.5 mg / kg / day, 14 mg / kg / day, 15 mg / kg / day, 16 mg / kg / day, 17 mg / kg / day, 18 mg / kg / day, 19 mg / kg / day, 20 mg / kg / day, 21 mg / kg / day, 22 mg / kg / day, 23 mg / kg / day, 24 mg / kg / day, 25 mg / kg / day, 26 mg / kg / day, 27 mg / kg / day, 28 mg / kg / day, 29 mg / kg / day, 30 mg / kg / day, 31 mg / kg / day, 32 mg / kg / day, 33 mg / kg / day, 34 mg / kg / day, 35 mg / kg / day, 36 mg / kg / day, 37 mg / kg / day, 38 mg / kg / day, 39 mg / kg / day, 40 mg / kg / day, 41 mg / kg / day, 42 mg / kg / day, 43 mg / kg / day, 44 In certain embodiments, belatacept may be administered to the transplant recipient at a dose of 10 mg / kg / day, 14.5 mg / kg / day, 15 mg / kg / day, 15.5 mg / kg / day, 16 mg / kg / day, 16.5 mg / kg / day, 17 mg / kg / day, 17.5 mg / kg / day, 18 mg / kg / day, 2-6 mg / kg / day, 3-7 mg / kg / day, 4-8 mg / kg / day, 5-9 mg / kg / day, 6-10 mg / kg / day, 7-11 mg / kg / day, 8-12 mg / kg / day, 9-13 mg / kg / day, 10-14 mg / kg / day, 11-15 mg / kg / day, 12-16 mg / kg / day, 13-17 mg / kg / day, or 14-18 mg / kg / day. In certain embodiments, belatacept may be administered to the transplant recipient at a dose of 10 mg / kg / day. In certain embodiments, the administration of belatacept may be altered as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0216] 5.3.12 Mycophenolate mofetil Mycophenolate mofetil (MMF), as used herein, may be included in the postoperative treatment regimen to suppress the immune system and inhibit the development of graft-versus-host disease in the recipient. Trade names for MMF may include CellCept® and Myfortic®. The postoperative treatment regimen may include a constant course of MMF administered to the recipient, followed by a tapering course.

[0217] In certain embodiments, the postoperative treatment regimen provided herein comprises administering MMF to the transplant recipient. In certain embodiments, MMF is administered on the day of transplant, on the day of transplant and for about 2 months, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days after transplant surgery. , 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, or 18 months later. In some embodiments, MMF is administered to the subject after transplant. In some embodiments, MMF is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 20 months, 24 months, or more than 24 months after transplantation. In some embodiments, MMF is administered about or at least about 1-2 months, 2-3 months, 3-4 months, 4-5 months, 5-6 months, 6-7 months, 7-8 months, 8-9 months, 9-10 months, 11-12 months, 1-6 months, 2-6 months, 3-6 months, 4-6 months, 6-12 months, or more than 6-12 months after transplantation.

[0218] In certain embodiments, a single dose of MMF may be administered. In certain embodiments, multiple doses of MMF may be administered. In certain embodiments, a flat dose of MMF may be administered. In certain embodiments, a tapering course of MMF may be administered. In certain embodiments, a flat dose of MMF followed by a tapering course of MMF may be administered postoperatively.

[0219] In certain embodiments, MMF is administered at about, at least about, or up to about 100 mg / dose, 200 mg / dose, 300 mg / dose, 400 mg / dose, 500 mg / dose, 600 mg / dose, 700 mg / dose, 800 mg / dose, 900 mg / dose, 1000 mg / dose, 1100 mg / dose, 1200 mg / dose, 1300 mg / dose, 1400 mg / dose, 1500 mg / day, 1600 mg / dose, 1700 mg / dose, The transplant recipient may be administered at a dose of 1800 mg / dose, 1900 mg / dose, 2000 mg / dose, 100-1000 mg / dose, 200-1200 mg / dose, 300-1300 mg / dose, 400-1400 mg / dose, 500-1500 mg / dose, 600-1600 mg / dose, 700-1700 mg / dose, 800-1800 mg / dose, 900-1900 mg / dose, or 1000-2000 mg / dose. In certain embodiments, the MMF may be administered to the transplant recipient at a dose of about 2 g / day. In certain embodiments, the MMF may be administered to the transplant recipient at a dose ranging from 500 to 1500 mg / dose. In certain embodiments, the MMF may be administered to the transplant recipient at a dose ranging from 500 to 1500 mg / dose once daily. In certain embodiments, MMF may be administered to a transplant recipient at a dose ranging from 500 to 1500 mg / day twice daily.

[0220] In certain embodiments, MMF can be administered to transplant recipient at a constant dose.The period during which the constant dose is administered can be 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, or more than 10 months after transplantation.In certain embodiments, MMF administered to transplant recipient can be tapered to discontinue. In certain embodiments, this tapering course may be carried out over 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, or more than 10 months.

[0221] In certain embodiments, MMF may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, or intraperitoneally, or any route of administration that allows for adequate activity of MMF by the recipient. In certain embodiments, MMF may be administered orally. In certain embodiments, MMF may be administered intravenously. In certain embodiments, administration of MMF may be altered as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0222] 5.3.13 mTOR inhibitors In certain embodiments, the methods described herein include administering an mTOR inhibitor to the recipient. Without being bound by theory, the mTOR inhibitor can be administered to the recipient to inhibit T cell and B cell activation and prevent transplant rejection. In certain embodiments, the mTOR inhibitor can be used in combination with or instead of tacrolimus. In certain embodiments, the mTOR inhibitor described in the methods presented herein can be rapamycin (e.g., sirolimus) or everolimus.

[0223] In some embodiments, the mTOR inhibitor is administered to the subject after transplantation. In some embodiments, the mTOR inhibitor is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 20 months, 24 months, or more than 24 months after transplantation. In some embodiments, the mTOR inhibitor is administered about or at least about 1-2 months, 2-3 months, 3-4 months, 4-5 months, 5-6 months, 6-7 months, 7-8 months, 8-9 months, 9-10 months, 11-12 months, 1-6 months, 2-6 months, 3-6 months, 4-6 months, 6-12 months, or more than 6-12 months after transplantation.

[0224] In certain embodiments, the postoperative regimen provided herein comprises administering rapamycin (or mTOR inhibitor) to transplant recipient after transplantation.In certain embodiments, rapamycin or mTOR inhibitor is administered daily.In certain embodiments, administration of rapamycin or mTOR inhibitor can be started immediately after transplantation, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, or more than 30 days after transplantation. In certain embodiments, administration of rapamycin or mTOR inhibitor is initiated about 1 month to about 12 months after transplantation. In certain embodiments, rapamycin is administered for at least 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, or at least 12 months. In certain embodiments, rapamycin is administered in 1, 2, 3, 4, or 5 daily doses.

[0225] In certain embodiments, the first dose of rapamycin or mTOR inhibitor is an initial amount and may be higher than subsequent daily doses. In certain embodiments, the dose of rapamycin or mTOR inhibitor is about 5-8 ng / mL. In certain embodiments, the first dose may be 1 mg / kg, 2 mg / kg, 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg, 9 mg / kg, 10 mg / kg, 11 mg / kg, 12 mg / kg, 1-4 mg / kg, 2-6 mg / kg, 4-8 mg / kg, 6-10 mg / kg, or 8-12 mg / kg. In certain embodiments, the daily dose may be 0.5 mg / kg, 1 mg / kg, 1.5 mg / kg, 2 mg / kg, 2.5 mg / kg, 3 mg / kg, 3.5 mg / kg, 4 mg / kg, 1-3 mg / kg, or 1.5-2.5 mg / kg. In certain embodiments, rapamycin is administered at an initial dose of 6 mg / kg, followed by daily doses of 2 mg / kg. In certain embodiments, rapamycin (or an mTOR inhibitor) is administered orally.

[0226] In certain embodiments, rapamycin or mTOR inhibitors may be administered postoperatively to the recipient at a dose sufficient to obtain a target whole blood level of 1-5 ng / ml, 2-10 ng / ml, 5-8 ng / ml, 4-12 ng / ml, 6-14 ng / ml, 8-16 ng / ml, 10-18 ng / ml, 12-20 ng / ml, 14-22 ng / ml, or 16-24 ng / ml. In certain embodiments, the target whole blood level may be 4-12 ng / ml.

[0227] In some embodiments, the mTOR inhibitor is administered to the subject at a dose of about, at least about, or up to about 1-5 ng / ml, 5-10 ng / ml, 8-10 ng / ml, 4-11 ng / ml, 10-15 ng / ml, 1-11 ng / ml, 2-12 ng / ml, 3-13 ng / ml, 4-14 ng / ml, 5-15 ng / ml, 6-16 ng / ml, 7-17 ng / ml, 8-18 ng / ml, 9-19 ng / ml, 10-20 ng / ml, or 15-20 ng / ml. In some embodiments, tacrolimus is administered to a subject at a dose of about, at least about, or up to about 1 ng / ml, 2 ng / ml, 3 ng / ml, 4 ng / ml, 5 ng / ml, 6 ng / ml, 7 ng / ml, 8 ng / ml, 9 ng / ml, 10 ng / ml, 11 ng / ml, 12 ng / ml, 13 ng / ml, 14 ng / ml, 15 ng / ml, 16 ng / ml, 17 ng / ml, 18 ng / ml, 19 ng / ml, 20 ng / ml, 22 ng / ml, 25 ng / ml, 30 ng / ml, or greater than 30 ng / ml.

[0228] In certain embodiments, the rapamycin or mTOR inhibitor may be administered to the transplant recipient in any convenient manner known in the art, including subcutaneously, intravenously, intravascularly, topically, intraarterially, intracranially, intramuscularly, orally, intraorbitally, by inhalation, transdermally, intraperitoneally, or any other route of administration that allows suitable activity of the rapamycin or mTOR inhibitor by the recipient. In certain embodiments, the rapamycin or mTOR inhibitor is administered orally. In certain embodiments, the administration of the rapamycin or mTOR inhibitor may be altered as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0229] In certain embodiments, mTOR inhibitor is everolimus.In certain embodiments, everolimus or mTOR inhibitor is administered twice a day.In certain embodiments, everolimus or mTOR inhibitor can be administered immediately after transplantation, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days or 30 days after transplantation. In certain embodiments, everolimus or an mTOR inhibitor is administered for at least 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, or at least 12 months.

[0230] In certain embodiments, the dose range of everolimus or mTOR inhibitor administered may be 0.25 mg / kg / dose, 0.5 mg / kg / dose, 0.75 mg / kg / dose, 1.0 mg / kg / dose, 1.25 mg / kg / dose, 1.5 mg / kg / dose, 1.75 mg / kg / dose, 2.0 mg / kg / dose, 0.25-0.5 mg / kg / dose, 0.5-0.75 mg / kg / dose, 0.75-1.0 mg / kg / dose, 1.0-1.25 mg / kg / dose, 1.25-1.50 mg / kg / dose, 1.50-1.75 mg / kg / dose, or 1.75-2.0 mg / kg / dose. In certain embodiments, everolimus or mTOR inhibitor is administered twice daily at a dose range of 0.75-1.0 mg / kg / dose. In certain embodiments, everolimus or the mTOR inhibitor is administered orally.

[0231] In certain embodiments, everolimus or mTOR inhibitors may be administered postoperatively to the recipient at a dose sufficient to obtain a target whole blood level of 0.1-5 ng / ml, 1-6 ng / ml, 2-7 ng / ml, 3-8 ng / ml, 4-9 ng / ml, 5-10 ng / ml, 6-11 ng / ml, 7-12 ng / ml, or 8-13 ng / ml. In certain embodiments, the target whole blood level may be 3-8 ng / ml. In certain embodiments, administration of everolimus or mTOR inhibitors may be modified as described herein to achieve and / or maintain mixed chimerism in the recipient.

[0232] In certain embodiments, the mTOR inhibitor can be temsirolimus, everolimus, sirolimus (rapamycin), ridaforolimus, a non-rapamycin analog mTOR inhibitor compound (such as, but not limited to, LY294002), wortmannin, quercetin, myricetin, staurosporine, or an ATP-competitive inhibitor.

[0233] 5.4 Porting Procedures for obtaining and transplanting organs or tissues are well known to those of skill in the art. Any procedure for surgical removal from a donor and surgical transplantation in a recipient may be used with the methods provided herein. In certain embodiments, the organ or tissue can be treated between removal and transplantation. In certain embodiments, the organ or tissue is treated between removal and transplantation as described in Section 5.3.1.

[0234] 5.5 Bone marrow injection Procedures for obtaining and injecting bone marrow are well known to those of skill in the art. In certain embodiments, the donor bone marrow is unprocessed. In certain embodiments, the donor bone marrow is processed to at least 1×, 2×, 3×, 4×, 5×, 6×, 7×, 8×, or at least 9×10 7 In certain embodiments, at least 1×, 2×, 3×, 4×, 5×, 6×, 7×, 8×, or at least 9×10 cells / kg are infused. 8 In certain more specific embodiments, 2-3×10 cells / kg are injected. 8Cells / kg are infused. In certain embodiments, the bone marrow infusion protocol and amounts may be modified as described herein to achieve and / or prolong mixed chimerism in the recipient.

[0235] 5.6 Outcome assessment In certain embodiments, the effectiveness of the conditioning regimen to achieve chimerism can be evaluated. Flow cytometry phenotyping can be used to determine the achievement of mixed chimerism (proportion of donor cells in lymphohematopoietic system) and the duration of mixed chimerism. Chimerism can be assessed using class I, HLA-specific monoclonal antibodies to detect donor and recipient leukocytes, and using variable short tandem repeat polymerase chain reaction (PCR) assays.

[0236] In certain embodiments, without being bound by theory, a combination of an anti-CD2 antibody or antigen-binding fragment thereof, tocilizumab (e.g., if CTS occurs or is administered on a particular day), cyclophosphamide (e.g., 60 mg / kg), rituximab, and / or thymic irradiation minimizes the risk, duration, or severity of CTS. In certain embodiments, without being bound by theory, a combination of an anti-CD2 antibody or antigen-binding fragment thereof, cyclophosphamide (e.g., 22.5 mg / kg), rituximab, fludarabine (e.g., 10 mg / m 2 ) and / or thymic irradiation minimizes the risk, duration, or severity of CTS. In certain embodiments, without being bound by theory, a combination of low dose cyclophosphamide (e.g., 22 mg / kg) and fludarabine (e.g., 10 mg / m 2 ) minimizes the risk, duration, or severity of CTS. In certain embodiments, the duration or severity of CTS may be measured as a clinical outcome assessment. In certain embodiments, any of the assays or experiments described herein (e.g., Examples section 6) may be used to assess the risk, duration, or severity of CTS.

[0237] In certain embodiments, functional assays can be used to detect biomarkers predictive of transplant rejection, including the presence of circulating donor-specific antibodies (DSA) and the level of B-cell activating factor (BAFF) in the recipient's serum, which can be determined by ELISA. In certain embodiments, flow cytometric analysis of circulating lymphocytes can be performed to determine the state of immune system reconstitution of the recipient. In certain embodiments, a mixed lymphocyte reaction (MLR) of the recipient's peripheral blood mononuclear cells can be performed to assess the response of recipient cells to donor cells and whether that response changes after transplant surgery. In certain embodiments, functional assays can be used to determine whether induction of tolerance to the transplanted organ has been achieved. These assays include flow cytometric analysis to determine the ratio of FoxP3+ T cells:CD4+ T cells as an indicator of the presence of regulatory T cells.

[0238] In certain embodiments, a biopsy of the transplanted graft can be performed to examine the health of the transplanted organ and determine evidence of tolerance induction or graft rejection. Such evidence visualized by biopsy can include proteinuria, infiltrating mononuclear cells, red blood cell fragments, arterial fibrinoid necrosis, or deposition of C4d. Tissue biopsies can be examined using routine microscopy, immunofluorescence, and electron microscopy (Panel B). In certain embodiments, total RNA can be isolated from the biopsy and mRNA levels of markers of interest can be determined. These markers of interest include the transcription factors FOXP3 and granzyme B. Transplant biopsies can occur 6 months, 12 months, 2 years, 3 years, 4 years, 5 years, 6 years, 7 years, 8 years, 9 years, or years after transplant surgery.

[0239] In certain embodiments, the outcome assessment of transplantation surgery includes monitoring the function of the organ transplanted in the recipient.For example, when kidney is the transplanted organ, the outcome assessment of transplantation surgery can monitor the glomerular filtration rate (GFR) of kidney.In certain embodiments, other assessments of the outcome of transplantation surgery include monitoring the incidence of infection, the incidence of opportunistic infection, the occurrence of treatment-related adverse events, and the quality of life of patients after transplantation.

[0240] In certain embodiments, the efficacy of the therapeutic methods described herein may be evaluated by determining the survival rate of the transplanted graft (e.g., liver or kidney). In certain embodiments, a biopsy of the transplanted graft (e.g., liver or kidney) may be performed to examine the health of the transplanted organ (e.g., liver or kidney) and to determine the induction of tolerance or evidence of graft rejection. Tissue biopsies may be examined using routine microscopy, immunofluorescence, and electron microscopy.

[0241] In certain embodiments, the efficacy of the therapeutic methods described herein can be determined by detecting treatment-triggered biopsy-proven acute rejection (tBPAR) in the recipient. In certain embodiments, tBPAR is not detected in the recipient at 10 months, 12 months, 15 months, 18 months, 20 months, 25 months, 30 months, 35 months, 40 months, 45 months, 50 months, 55 months, or 60 months after transplantation.

[0242] In certain embodiments, the outcome assessment of transplant surgery includes monitoring the function of the transplanted organ (e.g., liver or kidney) in the recipient. For example, the efficacy of the treatment methods described herein can be evaluated by measuring organ function at 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7.5 months, 9 months, 10.5 months, 12 months, 13.5 months, 15 months, 16.5 months, 18 months, 19.5 months, 21 months, 22.5 months, 24 months, 27 months, 30 months, 36 months, 42 months, 48 ​​months, or 54 months, or at 1-5 months, 5-10 months, 10-15 months, 15-20 months, 20-25 months, 25-30 months, 30-35 months, 35-40 months, 40-45 months, 45-50 months, 50-55 months, or 55-60 months after transplantation. Liver function may be determined by performing liver function tests such as, for example, measuring alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), gamma spherase (GGT), serum bilirubin, prothrombin time (PT), international normalized ratio (INR), and / or albumin. In certain embodiments, the therapeutic methods described herein result in the recipient having normal organ function (as determined by organ function tests) for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months after transplantation. In certain embodiments, the treatment methods described herein result in the recipient having better organ function (as determined by organ function tests) for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months after transplantation compared to patients receiving standard organ post-transplant care therapy.

[0243] In certain embodiments, the treatment methods described herein result in the recipient having an ALT level of 5-60 U / L, 7-55 U / L, 10-55 U / L, 15-50 U / L, 20-40 U / L, or 25-35 U / L for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0244] In certain embodiments, the treatment methods described herein result in the recipient having an AST level of 5-50 U / L, 8-48 U / L, 10-45 U / L, 15-40 U / L, or 20-30 U / L for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0245] In certain embodiments, the treatment methods described herein result in the recipient having an ALP level of 30-150 U / L, 40-129 U / L, 50-120 U / L, 60-110 U / L, 70-100 U / L, or 80-90 U / L for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0246] In certain embodiments, the treatment methods described herein result in the recipient having a GGT level of 5-70 U / L, 8-61 U / L, 10-50 U / L, 15-45 U / L, 20-40 U / L, or 25-35 U / L for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0247] In certain embodiments, the treatment methods described herein result in the recipient having a serum bilirubin level of 0.05-2 mg / dL, 0.1-1.5 mg / dL, 0.1-1.2 mg / dL, 0.5-1 mg / dL, or 0.7-1 mg / dL for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months after transplant.

[0248] In certain embodiments, the treatment methods described herein result in the recipient having a PT of 7-15 seconds, 8-14 seconds, 9-13 seconds, 9.4-12.5 seconds, or 10-12 seconds for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0249] In certain embodiments, the treatment methods described herein result in the recipient having albumin levels of 2-6 g / dL, 2.5-5.5 g / dL, 3-5 g / dL, 3.5-5 g / dL, or 4-4.5 g / dL for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0250] In certain embodiments, the treatment methods described herein result in the recipient having an INR below 1-3, 1.5-2.5, 1.5-2, or 1.1 for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0251] For example, the efficacy of the therapeutic methods described herein can be assessed by measuring renal function 10 months, 15 months, 20 months, 25 months, 30 months, 35 months, 40 months, 45 months, 50 months, 55 months, or 60 months after transplantation. Renal function can be determined, for example, by measuring serum creatinine and / or glomerular filtration rate. In certain embodiments, the methods described herein result in the recipient having normal renal function (as determined by serum creatinine and / or glomerular filtration rate (GFR)). In certain embodiments, the methods described herein result in the recipient having better renal function (as determined by serum creatinine and / or glomerular filtration rate) compared to patients undergoing standard liver post-transplant care regimens.

[0252] In certain embodiments, the treatment methods described herein result in the recipient having a serum creatinine level of 0.5-1.5 mg / mL, 0.6-1.4 mg / mL, 0.7-1.3 mg / mL, 0.8-1.2 mg / mL, or 0.9-1.1 mg / mL for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0253] In certain embodiments, the treatment methods described herein result in the recipient having a GFR above 40-90, 45-85, 50-80, 55-75, 60-70, or 90 for at least 10 months, at least 15 months, at least 20 months, at least 25 months, at least 30 months, at least 35 months, at least 40 months, at least 45 months, at least 50 months, at least 55 months, or at least 60 months post-transplant.

[0254] 5.7 Pharmaceutical Compositions Provided herein is a pharmaceutical composition comprising a pharma- ceutically effective amount of an anti-CD2 antibody or antigen-binding fragment thereof described herein. Also provided herein is a pharmaceutical composition comprising one or more of the second agents described herein (e.g., rituximab, cyclophosphamide, tocilizumab, corticosteroids, tacrolimus, MMF, antiproliferative agents, steroids, sirolimus, polyclonal rabbit antithymocyte globulin (rATG), fludarabine, B cell depleting antibodies, immunosuppressants, chemotherapeutic agents, antiproliferative agents, anti-IL6R antibodies, anti-neoplastic agents, and / or radiation agents). In some embodiments, the pharmaceutical composition is administered in conjunction with, prior to, or after thymic (or thymus) irradiation, transplantation, and / or cell (e.g., bone marrow) infusion. In some embodiments, the pharmaceutical composition is administered prophylactically (e.g., tocilizumab).

[0255] In some embodiments, the pharmaceutical composition is administered to the subject prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject prior to cell infusion (e.g., bone marrow cell infusion). In some embodiments, the pharmaceutical composition is administered to the subject after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject after cell infusion (e.g., bone marrow cell infusion). In some embodiments, the pharmaceutical composition is administered to the subject on the same day as the day of transplantation. In some embodiments, the pharmaceutical composition is administered to the subject on the same day as the day of cell infusion (e.g., bone marrow cell infusion). In some embodiments, the pharmaceutical composition is administered to the subject 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 days prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 days prior to cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 days after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, and / or 1 days after cell injection. In some embodiments, the pharmaceutical composition is administered to the subject 9 days before transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 9 days before cell injection. In some embodiments, the pharmaceutical composition is administered to the subject 6 days before transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 6 days before cell injection. In some embodiments, the pharmaceutical composition is administered to the subject 5 days before transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 5 days before cell injection. In some embodiments, the pharmaceutical composition is administered to the subject 4 days prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 4 days prior to cell injection. In some embodiments, the pharmaceutical composition is administered to the subject 3 days prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 3 days prior to cell injection.In some embodiments, the pharmaceutical composition is administered to the subject two days prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject two days prior to cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject one day prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject one day prior to cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject one day after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject one day after cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject at least once, at least twice, at least three times, at least four times, at least five times, at least six times, at least seven times, at least eight times, at least nine times, at least ten times, or at least more than ten times prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject at least once, at least twice, at least three times, at least four times, at least five times, at least six times, at least seven times, at least eight times, at least nine times, at least ten times, or at least more than ten times prior to cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, or more than 10 days prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, or more than 10 days prior to cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject at least 1 time, at least 2 times, at least 3 times, at least 4 times, at least 5 times, at least 6 times, at least 7 times, at least 8 times, at least 9 times, at least 10 times, or more than 10 times after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject at least 1 time, at least 2 times, at least 3 times, at least 4 times, at least 5 times, at least 6 times, at least 7 times, at least 8 times, at least 9 times, at least 10 times, or more than 10 times after cell infusion.In some embodiments, the pharmaceutical composition is administered to the subject at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, or at least more than 10 days after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, or at least more than 10 days after cell injection.

[0256] In some embodiments, the pharmaceutical composition is administered for consecutive hours / days prior to transplantation. In some embodiments, the pharmaceutical composition is administered for consecutive hours / days prior to cell infusion. In some embodiments, the pharmaceutical composition is administered for consecutive hours / days after transplantation. In some embodiments, the pharmaceutical composition is administered for consecutive hours / days after cell infusion. In some embodiments, the pharmaceutical composition is administered for consecutive hours / days after cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject for about, at least about, or up to about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject about, at least about, or up to about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, or more than 12 months after cell injection.

[0257] In some embodiments, the pharmaceutical composition is administered to the subject 9 days and / or 2 days prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 9 days and / or 2 days prior to cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject 6 days, 5 days, 4 days and / or 3 days prior to transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 6 days, 5 days, 4 days and / or 3 days prior to cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject 1 day prior to transplantation, the same day as transplantation, and / or the day after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 1 day prior to cell infusion, the same day as cell infusion, and / or the day after cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject 6 days prior to transplantation, 1 day prior to transplantation, the same day as cell infusion, the day after transplantation, and / or 6 days after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject 6 days prior to cell infusion, 1 day prior to cell infusion, the same day as cell infusion, the day after cell infusion, and / or 6 days after cell infusion. In some embodiments, the pharmaceutical composition is administered to the subject on the same day as the day of transplantation In some embodiments, the pharmaceutical composition is administered to the subject on the same day as the day of cell injection In some embodiments, the pharmaceutical composition is administered to the subject one day after transplantation In some embodiments, the pharmaceutical composition is administered to the subject one day after cell injection

[0258] In some embodiments, the pharmaceutical composition is administered to the subject after transplantation. In some embodiments, the pharmaceutical composition is administered to the subject about or at least about 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 21 days, 30 days, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 20 months, 24 months, or more than 24 months after transplantation. In some embodiments, the pharmaceutical composition is administered about or at least about 1-2 months, 2-3 months, 3-4 months, 4-5 months, 5-6 months, 6-7 months, 7-8 months, 8-9 months, 9-10 months, 11-12 months, 1-6 months, 2-6 months, 3-6 months, 4-6 months, 6-12 months, or more than 6-12 months after transplantation.

[0259] In some embodiments, a B cell depleting antibody (e.g., 375 mg / m 2 In some embodiments, a pharmaceutical composition comprising a B cell depleting antibody (e.g., 375 mg / m rituximab) is administered to the subject (e.g., day -9 and / or day -2 prior to transplantation / cell infusion). 2 In some embodiments, a pharmaceutical composition comprising an anti-neoplastic agent (e.g., 10 mg / m rituximab) is administered to the subject (e.g., day -9 and / or day -2 prior to transplantation / cell infusion and / or 5 days after transplantation / cell infusion and / or 12 days after transplantation / cell infusion). 2In some embodiments, a pharmaceutical composition comprising an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg of siplizumab) is administered to the subject (e.g., on day -6, -5, -4, and / or -3 prior to transplantation / cell infusion). In some embodiments, a pharmaceutical composition comprising an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg of siplizumab) is administered to the subject (e.g., on the day prior to transplantation / cell infusion (day -1), on the day of transplantation / cell infusion (day 0), and / or one day after transplantation / cell infusion (day 1)). In some embodiments, a pharmaceutical composition comprising an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg of siplizumab) is administered to the subject (e.g., 6 days prior to transplantation / cell infusion, on the day prior to transplantation / cell infusion (day -1), on the day of transplantation / cell infusion (day 0), and / or one day after transplantation / cell infusion (day 1)). In some embodiments, a pharmaceutical composition comprising an anti-CD2 antibody or antigen-binding fragment thereof (e.g., 0.6 mg / kg siplizumab) is administered to the subject (e.g., 6 days prior to transplantation / cell infusion, the day prior to transplantation / cell infusion (day -1), the day of transplantation / cell infusion (day 0), 1 day after transplantation / cell infusion (day 1), and / or 6 days after transplantation / cell infusion (day 6)). In some embodiments, a pharmaceutical composition comprising a chemotherapeutic agent (e.g., cyclophosphamide, e.g., 22.5 mg / kg) is administered to the subject (e.g., day -5 and / or day -4 prior to transplantation). In some embodiments, irradiation (e.g., thymic irradiation, 7 Gy) is administered to the subject prior to the day of transplantation. In some embodiments, a pharmaceutical composition comprising an immunosuppressant (e.g., tacrolimus, e.g., 8-10 ng / mL) is administered to the subject (e.g., on the day of transplantation and / or for about 1 month). In some embodiments, a pharmaceutical composition comprising an immunosuppressant (e.g., tacrolimus, e.g., 4-11 ng / mL) is administered to the subject (e.g., on the day of transplantation and / or about 9-12 months). In some embodiments, a pharmaceutical composition comprising an immunosuppressant (e.g., tacrolimus, e.g., 4-11 ng / mL) is administered to the subject post-transplantation (e.g., about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 24 months, or more than 24 months post-transplantation).In some embodiments, a pharmaceutical composition comprising an antiproliferative agent (e.g., MMF, e.g., about 1 g / day) is administered to the subject (e.g., on the day of transplantation and / or for about 1-2 months). In some embodiments, a pharmaceutical composition comprising an antiproliferative agent (e.g., MMF, e.g., about 1 g / day) is administered to the subject after transplantation (e.g., about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 24 months, or more than 24 months after transplantation). In some embodiments, a pharmaceutical composition comprising an immunosuppressant (e.g., a corticosteroid) is administered to the subject (e.g., on the day of transplantation and / or for about 6 months). In some embodiments, a pharmaceutical composition comprising an immunosuppressant (e.g., a corticosteroid) is administered to the subject (e.g., on the day of transplantation and / or for about 20 days). In some embodiments, a pharmaceutical composition comprising an immunosuppressant (e.g., a corticosteroid) is administered to the subject post-transplant (e.g., about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 24 months, or more than 24 months after transplant). In some embodiments, a pharmaceutical composition comprising an immunosuppressant (e.g., sirolimus, e.g., initial trough 5-8 ng / mL) is administered to the subject post-transplant (e.g., about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 24 months, or more than 24 months after transplant, and / or 1 month and / or 12 months after the date of transplant). In some embodiments, an anti-IL6R antibody (e.g., tosiri In some embodiments, a pharmaceutical composition comprising an anti-IL6R antibody (e.g., tocilizumab) is administered to the subject after transplantation (e.g., about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 24 months, or more than 24 months after transplantation).

[0260] In certain embodiments, the pharmaceutical compositions described herein may be formulated for subcutaneous, intravenous, intravascular, topical, intraarterial, intracranial, intramuscular, oral, intraorbital, inhalation, intraperitoneal, intraosseous, intratracheal, sublingual, buccal, rectal, intradermal, intrathecal, intramedullary, or transdermal administration routes. In some embodiments, the pharmaceutical compositions described herein are formulated for intravenous administration. In some embodiments, the pharmaceutical compositions described herein are formulated for subcutaneous administration.

[0261] In certain embodiments, the composition formulated for intravenous or subcutaneous administration may be a solution, suspension, or emulsion. In certain embodiments, the agent described herein (e.g., an anti-CD2 antibody or antigen-binding fragment thereof) is formulated for intravenous or subcutaneous administration by combining the agent with a pharma- ceutically appropriate vehicle. In certain embodiments, the vehicle used may be, but is not limited to, water, saline, Ringer's solution, dextrose solution, glycerol, ethanol, 1-10% human serum albumin, 5% dextrose in water, N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, propylene glycol, polyethylene glycol 400, diethylene glycol monoethyl ether, TWEEN 80, TWEEN 20, polyoxyl-35 castor oil, polyoxyl 40 hydrogenated castor oil, caprylocaproyl macrogol-8 glyceride, soybean oil, polyoxyethylated oleic acid glyceride, and medium chain mono- and diglycerides. In certain embodiments, liposomes and non-aqueous vehicles (eg, fixed oils) may also be used to administer an agent described herein (eg, an anti-CD2 antibody or antigen-binding fragment thereof).

[0262] In certain embodiments, the vehicle may contain additives to maintain isotonicity (e.g., sodium chloride, mannitol). In certain embodiments, the vehicle may contain additives to maintain chemical stability. These additives may include, but are not limited to, buffers (e.g., maleic acid, tartaric acid, lactic acid, citric acid, acetic acid, sodium bicarbonate, and sodium phosphate), and preservatives (e.g., detergents, oxidizing agents, and ionic buffers). The resulting pharmaceutical formulation is sterilized by known or suitable techniques.

[0263] In certain embodiments, intravenous administration of the pharmaceutical compositions described herein may be administered as a bolus injection, slow intravenous injection, or continuous intravenous injection. In some embodiments, subcutaneous administration of the pharmaceutical compositions described herein may be administered as a bolus injection.

[0264] 5.8 Kits Provided herein are kits comprising a pharmaceutical composition described herein in one or more containers. Provided herein are kits comprising an anti-CD2 antibody or antigen-binding fragment thereof described herein and / or one or more second agents (e.g., rituximab, cyclophosphamide, tocilizumab, corticosteroids, tacrolimus, MMF, anti-proliferative agents, steroids, sirolimus, fludarabine, chemotherapeutic agents, anti-IL6R antibodies, B cell depleting antibodies, immunosuppressants, anti-tumor agents, and / or anti-proliferative agents). In some embodiments, the kit comprises a pharmaceutical composition described herein in one or more containers. In some embodiments, the kit comprises one or more anti-CD2 antibodies or antigen-binding fragments thereof and / or a second agent or composition of the present disclosure in the same or different containers. In some embodiments, the kit comprises at least one anti-CD2 antibody or antigen-binding fragment thereof in the same or different containers. In some embodiments, the kit comprises a library of anti-CD2 antibodies or antigen-binding fragments thereof. In some embodiments, the kit comprises another active agent / second agent. In some embodiments, the kit includes a control and / or reference (e.g., a reference antibody). In some embodiments, the kit may further include reagents and / or instructions for making and / or synthesizing the compounds and / or compositions described herein. In some embodiments, the kit may also include one or more buffers. In some embodiments, the kit includes another agent (e.g., another active agent) in the same or different container. In some embodiments, the container containing the agent (e.g., an anti-CD2 antibody or antigen-binding fragment thereof) is provided for single or multiple administration. In some embodiments, the agent (e.g., an anti-CD2 antibody or antigen-binding fragment thereof) is present in the container in the kit in an amount sufficient for multiple doses, multiple uses, or multiple administrations. In some embodiments, the kit includes other components necessary for administration of the agent (e.g., an anti-CD2 antibody or antigen-binding fragment thereof) (e.g., the kit includes a syringe, catheter, cannula, pump, or any injection device).In certain embodiments, the kits include devices that can be used to administer the pharmaceutical compositions described herein, including, but not limited to, syringes, needleless injectors, drip bags, infusion pumps, pumps, patches, and inhalers. In some embodiments, the kits include pharma- ceutically acceptable carriers, diluents, excipients, and / or buffers in the same or separate containers as those holding one or more agents described herein. In some embodiments, the kits include components and / or instructions for thymic irradiation.

[0265] The components of the kit may be in separate containers or combined in a single container. In some embodiments, the kit components may be packaged in either aqueous media, powdered, crystalline, or lyophilized form. Containers in which the pharmaceutical compositions may be packaged include, but are not limited to, bottles, pouches, ampoules, tubes, inhalers, bags, vials, and containers. The container means of the kit may include at least one of a vial, test tube, flask, bottle, needleless syringe, drip bag, infusion pump, pump, patch, inhaler, ampule, syringe, or other container means into which the components may be disposed. In some embodiments, the components are suitably aliquoted. In some embodiments, when there is more than one kit component, the reagents and corresponding labels may be packaged together. In some embodiments, the kit includes a second, third, or other additional container into which the additional components may be separately disposed. In some embodiments, the kit includes a second container means for containing a sterile, pharma- ceutically acceptable buffer, and / or other diluent. In some embodiments, various combinations of components are included in one or more vials. In some embodiments the kits will include a means for containing the antibodies and / or compounds and / or compositions of the present disclosure in close confinement for commercial sale. Such containers may include injection or blow molded plastic containers into which the desired vials are retained.

[0266] In some embodiments, the kit components are provided in one and / or more liquid solutions. In some embodiments, the liquid solution is an aqueous solution or a sterile aqueous solution. In some embodiments, the kit components are provided as dry powder(s). When reagents and / or components are provided as dry powders, such powders can be reconstituted by the addition of an appropriate volume of solvent. In some embodiments, the solvent is provided in a separate container means. In some embodiments, the labeling dye is provided as a dry powder. In some embodiments, the labeling dye is provided in an amount of about, at least about, or up to about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 120, 130, 140, 150, 160, 170, 180, 190, 200, 300, 400, 500, 600, 700, 800, 900, 1000 micrograms. In some embodiments, the dye can be resuspended in any suitable solvent, such as DMSO.

[0267] In some embodiments, the kit includes instructions for using the components of the kit. In some embodiments, the kit contains dosages, administration, use, storage conditions, a list of diseases that can be treated or prevented by using one or more of the kits, and / or instructions related to the use of the components. In some embodiments, the instructions are recorded on a suitable recording medium. For example, the instructions can be printed on a substrate such as paper, a tag (e.g., an adhesive tag), or plastic. In some embodiments, the instructions are present in the kit as a package insert or on a label attached to a container or a component of the kit. In some embodiments, the instructions are provided as an electronic storage data file present on a suitable computer-readable storage medium, such as a CD-ROM, a diskette, a USB storage device, or a flash drive. In some embodiments, the instructions are not present in the kit, but are present in a remote source, for example, via the Internet.

[0268] 5.9 Equivalents and Incorporation by Reference The present invention is not limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described will become apparent to those skilled in the art from the foregoing description and the accompanying drawings. Such modifications are intended to be included within the scope of the appended claims.

[0269] Various publications, patents, and patent applications are cited herein, the disclosures of which are incorporated by reference in their entireties. EXAMPLES

[0270] 6. Working Example 6.1 Example 1. Safety and Tolerance Study of an Anti-CD2 Antibody or Antigen-Binding Fragment thereof (e.g., Siplizumab) in Combination with Donor Bone Marrow Cell Infusion and Non-Myeloablative Conditioning (Including Fludarabine and Cyclophosphamide) for Tolerance Induction in de novo Living Donor Kidney Transplantation In this study, an anti-CD2 antibody or its antigen-binding fragment (e.g., siplizumab) is combined with donor bone marrow cells and reduced-intensity conditioning with fludarabine and cyclophosphamide to determine allogeneic tolerance in de novo living donor kidney transplant recipients.

[0271] Primary objective: To induce renal allograft tolerance (proportion of recipients who discontinued immunosuppressants while maintaining good renal function at 24 months after transplantation).

[0272] Key secondary objectives: To determine the composite incidence of biopsy-proven acute rejection (BPAR), death and graft loss (with and without loss to follow-up) at 24 months post-transplant, and to determine the incidence and mean fluorescence intensity (MFI) of de novo DSA (donor-specific antibodies) at 24 months post-transplant.

[0273] secondary purpose To evaluate the safety, tolerability, and activity over time of anti-CD2 antibodies or antigen-binding fragments thereof (e.g., siplizumab) and fludarabine-based conditioning regimens Incidence and grade of CTS Incidence of death and graft loss Incidence of biopsy-proven acute rejection (BPAR) and treated BPAR (according to the Banff classification) Renal function (estimated glomerular filtration rate (eGFR)) and change in renal function over time (e.g., assessed at 3, 6, 12, and 24 months, then annually out to 60 months) Incidence of serious adverse events and adverse events Incidence of severe or clinically significant opportunistic infections Incidence of BK viremia, infection and nephropathy Incidence of malignant tumors Incidence and severity of GvHD Incidence of new onset diabetes after transplant (NODAT) -Incidence of chronic rejection [Table 7]

[0274] Purpose of the test: -Assessment of lymphodepletion and recovery, including Treg and T effector / memory cells, by flow cytometry Time to neutrophil recovery after transplant (ANC>500 / mm3) Time to platelet recovery after transplant (platelets >20,000 / mm3 and transfusion independence) Pharmacokinetic characterization of anti-CD2 antibodies or antigen-binding fragments thereof (e.g., siplizumab) Assessment of donor-specific lymphoid and bone marrow chimerism: By flow cytometry - Variable short tandem repeat (VNTR) PCR-based DNA microsatellite analysis Incidence or progression of abnormal histologic findings of cellular or antibody-mediated rejection (i.e., TG, IF / TA, C4d, BK / polyomavirus nephropathy) Follow-up evaluation and safety monitoring of donors regarding hematological and renal function, as well as other complications in living donors Assessment of biomarkers of tolerance (e.g., FoxP3 in biopsies) - Evaluation of a time-course cytokine panel Assessment of HLA eplete mismatch burden and its relationship to outcome [Table 8]

[0275] Study Design: Approximately 12 subjects will be enrolled in this study. The primary objective will be evaluated at 24 months, and recipients will remain in the study for up to 5 years post-transplant for follow-up (see Figure 1). The study will evaluate a treatment regimen based on an anti-CD2 antibody or its antigen-binding fragment (e.g., siplizumab) in 12 patients. Based on the primary objective outcomes (i.e., proportion of patients with good renal function and discontinued immunosuppression and acceptable safety profile at 24 months), the protocol can be amended to allow enrollment of additional patients.

[0276] During the screening period (days -37 to -10) and after informed consent is signed, baseline subject information is obtained from donors and recipients, including date of birth, age, sex, race and ethnicity. In addition, pertinent medical history is reviewed, including current medical conditions, causes of end-stage renal disease (ESRD), dialysis and medication history. A complete physical examination, vital signs, laboratory evaluation, and pregnancy test are performed.

[0277] Pre-transplant screening procedures include donor / recipient HLA typing (molecular), complement-dependent cytotoxicity (CDC) lymphocyte crossmatch (or virtual crossmatch), qualitative DSA with single antigen bead (SAB) assay, and donor / recipient viral serology. Standard care procedures performed prior to consent may be considered in determining subject eligibility (e.g., HLA / ABO typing, specific laboratory results). Recipients and their respective donors who complete the screening period and meet all inclusion criteria are enrolled in the study.

[0278] Day -9 is defined as the start of the study treatment period (conditioning regimen) and day 0 is defined as the day of transplant surgery. The first study treatment visit (day -9) is conducted on an outpatient basis. Recipients are admitted to the hospital on day -6 before administration of the next study treatment and remain in the study as inpatients until discharge from the hospital after transplant. Discharge from the hospital varies based on the clinical status of the donor and recipient and is determined at the discretion and judgment of the clinical team and physicians. Following discharge from the hospital, subjects return to the clinic for weekly visits until week 11, monthly visits from months 3 to 12, quarterly visits up to month 24, and then every 6 months until the end of study (EOS) / month 60. Throughout these visits, safety and PK / PD assessments are collected according to Figure 2.

[0279] The recipient begins conditioning with an infusion of rituximab (375 mg / m2) on day -9. Fludarabine (10 mg / m2) is administered on days -6, -5, -4, -3, with cyclophosphamide (22.5 mg / kg) on ​​days -5 and -4. A second dose of rituximab is administered on day -2, and thymic irradiation of 700 cGy is administered on day -1. An anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) is administered at a dose of 0.6 mg / kg on days -1, 0, and 1. Kidney transplantation and donor bone marrow cell infusion are performed on day 0.

[0280] IV steroids are administered based on dose and tolerance on the day of transplant and until approximately post-op day 4. During the first week after transplant, subjects are transitioned from IV to oral steroids with a slow taper off steroids over the course of 6 months.

[0281] Controlled-concentration background immunosuppression is initiated with tacrolimus (target trough 8-10 ng / mL) on perioperative day 0, then switched to sirolimus (SRL) at week 4. Sirolimus (initial target trough 5-8 ng / mL) is continued through month 6. In some cases, mycophenolate is not used in this study. Per-protocol biopsies are performed at month 6, and SRL doses are decreased (e.g., to achieve target trough concentrations of 3-5 ng / mL) if a priori-defined immunosuppression weaning criteria are met. SRL is completely weaned at month 12 post-transplant based on the 1-year protocol biopsy and assessment of allograft or renal function.

[0282] Standard safety assessments include vital signs, physical examination, ECG, clinical laboratory evaluations (hematology, blood chemistry, and urinalysis), AE and SAE monitoring. In addition to standard clinical laboratory evaluations, subjects will be monitored regularly for signs and symptoms of coagulopathy and inflammation, hematology, or nephrotoxicity / rejection. Subjects' serum creatinine, serum cytokines, and renal injury markers will be measured frequently in the first few weeks after transplant, with a focus thereafter on renal injury, dysfunction, or acute rejection. Changes in renal function will be assessed via serum creatinine and estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) methods. All biopsies will be histopathologically evaluated and classified in real time based on the Banff classification of renal allograft pathology guidelines by a trained renal pathologist. Exploratory urinary injury biomarker samples will be collected for future analysis that may help assess the type and general location of renal injury, i.e., glomerular or ureteral. Extensive immunophenotyping by fluorescence-activated cell sorting (FACS) analysis will be performed during the study to assess donor chimerism and changes in leukocyte subsets and recovery following conditioning and donor bone marrow cell infusion.

[0283] Inclusion criteria for recipient subjects: 1. Understand the study requirements and are able to provide written informed consent before any study evaluations are performed. 2. Male or female recipients aged 18-60 years 3. Receive your first kidney transplant 4. Renal transplant recipients from non-HLA-identical but at least haploidentical, ABO-compatible living donors 5. Able to comply with the schedule of study visits, especially after discontinuation of immunosuppression. 6. Stable cardiopulmonary status as determined by the investigator with ejection fraction >40% within 3 months of transplant and eligible for transplant. 7. EBV seropositivity within 6 months of screening. 8.- A negative SARS-CoV-2 nucleic acid amplification test (NAAT) performed within 72 hours of day 9 (start of the treatment period). 9. Recipients are free of other locally endemic infections that may be contraindications to solid organ or BMT / HSCT transplantation according to applicable guidelines. 10. Male study subjects are willing to maintain barrier contraception (condoms) and agree not to father children until 180 days after the last dose of fludarabine.

[0284] Recipient: Histocompatibility testing (HLA / ABO typing): Pre-transplant high-precision HLA typing as well as HLA class I and class II antigens (including HLA A, B, C, DR, DP and DQ) are performed. In addition, serological testing of blood groups as well as B and T cell flow cytometric cross-match testing are performed. In addition to providing information on the quality of the match, high-precision HLA results ensure the ability to detect hematopoietic cells of donor origin by FACS and immunohistochemistry. Calculate the test assessment of the eplet mismatch load.

[0285] Recipient: Sensitization (PRA, DSA) History: Potential subjects' sera are screened prior to transplant for reactivity to the proposed donor as well as against a panel of HLA specificities (PRA). Screening for anti-donor HLA antibodies (DSA) utilizes a single antigen bead assay (e.g., Luminex).

[0286] Recipient: Infectious disease screening Cytomegalovirus IgG antibody Cytomegalovirus IgM antibody Epstein-Barr virus nuclear antigen IgG antibody Hepatitis B core antibody ·Hepatitis B surface antibody ·Hepatitis B surface antigen ·Hepatitis C antibody ·TB QuantiFERON HIV I / II Screen ·HTLV1 antibody ·Syphilis serology SARS-CoV-2 nucleic acid amplification test (tested within 72 hours on the -9th day)

[0287] Recipient: Clinical Laboratory Testing ·Complete blood count diff (CBC) Coagulation Panel Comprehensive metabolic panel (chemistry) Lipid Panel T3 / T4 / TSH Urine testing Serum pregnancy test (for women of childbearing potential) CMV DNA NAAT (baseline assessment; tested within 72 hours of transplant)

[0288] Donor Inclusion Criteria: 1. Donor subjects are able to provide informed consent before any study evaluations are conducted. 2. Male or female, aged 18 years or older or 65 years or younger 3. Healthy according to conventional donor history (physical examination, laboratory evaluation, and psychosocial evaluation). 4. Negative for HBsAg, HIV, HCV (RNA) and HTLV-1. Viral test results within 28 days of study day 0 (day of surgery) are acceptable. 5. Negative SARS-CoV-2 NAAT within 72 hours of Study Day 9 (start of the recipient's conditioning regimen). 6.- Willing to adhere to COVID protocols (e.g., social distancing, mask use) and facility guidelines from Day 9 through the day of surgery. 7. Test negative for latent TB infection as detected by Quantiferon Gold Plus IGRA (or the current standard interferon gamma release assay for TB). 8. Absence of other locally endemic infections that are contraindications to solid organ or BMT / HSCT transplantation according to applicable guidelines.

[0289] Recipient Exclusion Criteria: 1. Use of other investigational drugs (or enrollment in another investigational drug study) within 30 days of screening or within 5 half-lives of the drug, whichever is longer. 2. History of hypersensitivity to the study treatment or any of its excipients, or to agents of a similar chemical class (e.g., MEDI-507, tacrolimus, sirolimus, cyclophosphamide, or rituximab). 3. Recipients with end-stage renal disease due to focal segmental glomerulosclerosis (FSGS) or membranoproliferative glomerulonephritis (MPGN / C3 glomerulopathy). 4. Recipients with donor-specific anti-HLA antibodies (DSA) as measured by single antigen bead (e.g., Luminex) assay(s) within 28 days prior to transplant. 5. Recipient with a positive donor crossmatch result (assayed according to each institution) within 28 days of transplant. 6. Recipients with panel reactive antibodies (PRA>20%) within 2 months of transplant. 7. Subject with baseline leukopenia (WBC < 2,000 / mm3) or thrombocytopenia (platelet count < 100,000 / mm3). 8. Seropositive for HIV-1 or HBsAg. Subjects who are seropositive for Hepatitis C virus will be excluded without evidence of sustained virologic response (SVR) following anti-HCV treatment. Outcome within 6 months of transplantation will be accepted. 9. Have latent TB infection as detected by Quantiferon Gold Plus IGRA (or the current standard interferon gamma release assay for TB). 10. Subject with a history of cancer other than basal cell carcinoma of the skin or in situ carcinoma of the cervix. 11. Subject with clinically significant laboratory abnormalities that would prevent study participation (e.g., >2.5 x ULN values ​​for (a) liver chemistry [(ALT, AST, ALP), (b) bilirubin, (c) coagulation studies (PT, aPTT)]). 12. Subject who, in the opinion of the Investigator, is unable to give informed consent to the study or is unable or unwilling to comply with the study requirements outlined in the protocol. 13. Subject with any other clinically significant health condition or laboratory abnormality that, in the Investigator's judgment, interferes with the subject's ability to participate in the study. 14. Subject who has received any live attenuated vaccine within 2 months of planned transplant. 15. Pregnant or lactating (breast-feeding) women, where pregnancy is defined as a woman's state from conception through the end of gestation, confirmed by a positive human chorionic gonadotropin (hCG) laboratory test.

[0290] Investigational Product: Anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab (TCD601)) is applied at a dose of 0.6 mg / kg per administration. Anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) is provided in a 6 mL vial containing 60 mg and is provided at a concentration of 10 mg / mL. The subject's weight is measured within 24 hours of each infusion administration and this weight is the basis for the final dose calculation and formulation. The dose is calculated by the following formula: dose (mg) = (patient weight (kg) x dose level (mg / kg)). For example, a subject weighing 70 kg receiving a dose of 0.6 mg / kg can receive 42 mg of anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) (70 kg x 0.6 mg / kg = 42 mg) and would require one vial of anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab). The product is then administered to the subject via IV infusion using a syringe pump.

[0291] Conditioning regimen Anti-CD2 antibodies (e.g., siplizumab, 0.6 mg / kg): Days -1, 0, +1 Rituximab, 375 mg / m2; days -9 and -2 Fludarabine, 10 mg / m2: days -6, -5, -4, -3 Cyclophosphamide, 22.5 mg / kg: days -5, -4. ·Thymus irradiation, 700cGy: -1st day

[0292] Recipients receive a conditioning regimen beginning with rituximab on days -9 and -2, anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) on days -1, 0, and 1, fludarabine (10 mg / m2) on days -6, -5, -4, and -3, cyclophosphamide (22.5 mg / kg) on ​​days -5 and -4, and thymic irradiation 700 cGy on day -1. Methylprednisolone 500 mg IV bolus is given on days 0 and 1, slowly tapered from IV to oral steroids during the first postoperative week, then oral steroids are discontinued at month 6.

[0293] To prevent the risk of hemorrhagic cystitis and hematuria due to cyclophosphamide, MESNA (2-mercaptoethanesulfonate sodium) is given and the patient is hemodialyzed before and after cyclophosphamide administration. A simultaneous kidney donor bone marrow transplant is performed on day 0. Tacrolimus (trough 8-10 ng / mL) is started at the time of transplant and given until week 4 when the patient is switched to sirolimus (initial target trough 5-8 ng / mL).

[0294] Anti-CD2 antibody or antigen-binding fragment thereof premedication: Prior to each infusion of anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab), subjects may receive premedication including 650-1000 mg of acetaminophen (or paracetamol) and an H1 antagonist (antihistamine, e.g., 25 mg of diphenhydramine or 4 mg of chlorpheniramine) to minimize signs and symptoms of infusion reactions. Additionally, for the first dose of anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) (Day -1), 8 mg / kg of methylprednisolone sodium succinate may be administered prior to beginning the infusion. Administration of the required premedication may occur no less than 30 minutes and no more than 3 hours prior to the start of the infusion.

[0295] Administration of anti-CD2 antibody or antigen-binding fragment thereof (days -1, 0, and 1): A first dose of anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab; 0.6 mg / kg) is administered on day -1. Doses of anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) can be administered at intervals of about 20-24 hours. The anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) solution is infused intravenously via a syringe pump over a period of about 1 hour. Premedication precedes administration of anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab) on days -1 and 1.

[0296] On day 0, the infusion is administered pre-operatively or intraoperatively, and the infusion may be timed so that completion is not 4 hours before revascularization and perfusion of the allograft. In consultation with the anesthesiologist, premedication can be coordinated with any preoperative medications to avoid therapeutic overlap. If administered intraoperatively, the infusion should be completed prior to revascularization and administration of bone marrow cell infusion (BMCI). This ensures that both donor and alloreactive T lymphocytes are suppressed and depletion begins hours and days after transplantation. After each administration, subjects are closely monitored (minimum 2 hours) for infusion reactions.

[0297] Infusions can be given directly into a peripheral vein or into a separate lumen in an indwelling multilumen central catheter (and are not given simultaneously with other medications, e.g., due to unknown compatibility with other IV medications). Record the date, start time, completion time, and total dose of administration of the anti-CD2 antibody or antigen-binding fragment thereof (e.g., siplizumab).

[0298] If any notable AEs and / or SAEs, including loss of efficacy and / or relevant pharmacokinetic (PK) / pharmacodynamic (PD) data are collected during the study, modifications to the next dose level planned throughout the study may be considered and implemented.

[0299] Rituximab Premedication: Acetaminophen (650-1000 mg PO), an H1-antagonist (antihistamine, e.g., 25-50 mg diphenhydramine, 4 mg chlorpheniramine), and hydrocortisone sodium succinate (e.g., Solu-Cortef; 100 mg IV) can be administered to subjects 2 hours prior to each dose of rituximab.

[0300] Rituximab administration (days -9 and -2): Rituximab (375 mg / m 2 / dose) is administered on days -9 and -2. In subjects undergoing ongoing renal replacement therapy, rituximab may be administered several hours after hemodialysis. The first rituximab solution for infusion can be administered intravenously at an initial rate of 50 milligrams per hour (mg / hr). The rate can be increased by 50 mg / hr every 30 minutes up to a maximum of 400 mg / hr. A second rituximab dose is administered on day -2. If the subject tolerates the first infusion, the second infusion can be initiated at 100 milligrams per hour (mg / hr) and titrated at 100 mg / hr every 30 minutes up to a maximum of 400 mg / hr.

[0301] Subjects are closely monitored for infusion reactions (minimum 1 hour). If the subject does not tolerate the first infusion, initial infusion guidelines can be followed. If hypersensitivity or infusion-related events occur, the infusion can be temporarily slowed or interrupted. The infusion can then be continued at half the previous rate upon improvement of symptoms. Start and stop times of rituximab administration as well as total dose can be recorded.

[0302] Fludarabine Premedication / Treatment Hemodialysis: Subjects who did not receive dialysis prior to transplant will require hemodialysis treatment after the first and last dose of fludarabine as prophylaxis against fludarabine toxicity. Recipients without pre-existing vascular access will be seen by a nephrologist on or before day -6 in preparation for vascular access and catheter insertion in preparation for hemodialysis during pretreatment. Hemodialysis may be administered 5-7 hours after the first dose of fludarabine on day -6 and 5-7 hours after the last dose of fludarabine on day -3. Duration (or dose) of dialysis may be close to 4 hours in duration or follow local nephrologist recommendations.

[0303] Dialysis days, dates and duration can be recorded. If the subject's eGFR is less than 10 mL / min and the subject is receiving hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) at the time of study enrollment, an additional hemodialysis will be administered on day -1.

[0304] Fludarabine administration (days -6, -5, -4, and -3): Fludarabine (10 mg / m 2 ) may be administered intravenously over approximately 30 minutes on days -6, -5, -4, and -3. Antiemetic therapy to prevent nausea and vomiting (e.g., use of granisetron or alternative) is recommended while following fludarabine labeling and prophylaxis per local investigator standards.

[0305] Cyclophosphamide Premedication / Treatment: Prior to administration of cyclophosphamide on days -5 and -4, recipients may receive premedication (e.g., glucocorticoids, antihistamines, anxiolytics, and antiemetics) for prevention of nausea, vomiting, and infusion reactions. Subjects may receive prophylaxis against hemorrhagic cystitis with MESNA as follows: Oliguric subjects: MESNA, 15 mg / kg, is administered via 4 bolus intravenous injections 15 minutes before and 3, 6, and 9 hours after cyclophosphamide administration. Non-oliguric subjects: MESNA, 15 mg / kg, is administered via 4 bolus intravenous injections 15 minutes and 3, 6, and 9 hours prior to cyclophosphamide administration, and IV hydration (e.g., 5% dextrose, with 1500 mL / M2 / 24 hours tolerated) is initiated 4 hours prior to cyclophosphamide. Bladder irrigation may also be performed if the subject is oliguric.

[0306] Cyclophosphamide Administration (Day -5 and Day -4): Subjects will receive cyclophosphamide, 22.5 mg / kg / day (based on ideal or actual body weight, whichever is less). Cyclophosphamide will be dissolved in 250 mL 5% dextrose and infused via intravenous infusion over 1 hour. Administration of cyclophosphamide will occur at least 20 hours after hemodialysis.

[0307] Thymic irradiation (day -1): 7 Gy of thymic irradiation will be administered as a single dose on day -1. The irradiation field and dose rate will be performed according to the standards of the clinical trial site.

[0308] Donor nephrectomy and bone marrow procurement: Donors undergo nephrectomy and bone marrow cell procurement under general anesthesia on day 0 (the day of transplant). Unfractionated donor bone marrow cells (minimum 2 x 10 of recipient body weight) are 8 TNC / kg (planned) is prepared for injection according to the following: Prior to procurement, use recipient weight and 2 x 10 for donor collection. 8 Calculate target number of cells based on TNC / kg. A midpoint collection assessment of the number of TNC harvested can also be performed to assess the progress of collection. · Bone marrow is harvested from each posterior iliac crest using a needle / trocar set and aspirated into a heparinized syringe with a maximum of 5-10 mL of bone marrow per aspiration. Repeated aspirations are then performed by reinserting the needle through the same skin puncture site into different bone sites until approximately 20-33% of the intended volume has been collected. The skin puncture site is then changed and the aspiration repeated. This method utilizes 3-5 skin puncture sites covering each iliac crest. Prior to completion of bone marrow procurement, a TNC count may be performed; if additional cells are required, they may be obtained as long as they do not exceed institutional guidelines for BM volume. Once enough cells are obtained, the bone marrow is filtered to remove fat, bone and blood clots. To prevent clotting, an anticoagulant may be added to the bone marrow extract (e.g., heparin or anticoagulant citrate-dextrose, or according to the local institution). To minimize the effect of the anticoagulant upon infusion (considering the risk of intra- and post-operative bleeding), the bone marrow is depleted of plasma and partially resuspended in saline. · Plasma is removed by transferring the bone marrow product into a standard blood transfer pack container, centrifuging, and expressing the supernatant plasma in a plasma extractor into another transfer pack container. A volume of intravenous 0.9% sodium chloride equivalent to approximately 1 / 2 the volume of expressed plasma is then added to the bone marrow cells. This also reduces the volume of the infusion. · Bone marrow cell samples are characterized for total volume, total nucleated cell content, total CD3+ T cell content, and total CD34+ cell content. · The final bone marrow sample can be stored in a cooler or transported back to the operating room and preserved in an appropriate manner for infusion into the recipient.

[0309] Recipient Engraftment and Bone Marrow Cell Infusion: On study day 0, transplant recipients receive the allograft. A wedge or needle baseline biopsy is obtained from the allograft prior to implantation. Following revascularization of the allograft and confirmation of the absence of bleeding or leakage from the vascular anastomoses, recipients undergo bone marrow cell infusion. Cells are infused intravenously at a rate of approximately 300-500 mL / hr. Infusion may begin within 4 hours after reperfusion.

[0310] Partial thromboplastin times are measured midway through the infusion (or if bleeding appears excessive) and after the infusion is completed. Protamine 25 mg can be given intravenously for a PTT of >60 seconds or an elevated PTT if it is thought to be the cause of bleeding.

[0311] Concomitant immunosuppressants may include: immediate release tacrolimus (TAC): 0.5 mg, 1.0 mg, or 5.0 mg capsules or IV; sirolimus (SRL): 0.5, 1.0 or 2.0 mg tablets or oral solution; and corticosteroids (CS): oral and IV administration.

[0312] Tacrolimus administration (day 0-week 4): TAC is administered orally (po) twice daily (BID) as a capsule or tablet and adjusted to maintain serum trough (C0) concentrations within the 8-10 ng / mL target range. At week 4, TAC is discontinued and subjects are switched to SRL, with SRL trough levels in the 5-8 ng / mL range. The switch can be made earlier if necessary (e.g., BK infection). If oral administration is not feasible or practical, IV TAC containin...

Claims

1. 1. A pharmaceutical composition for use in a method of transplanting an organ or tissue from a donor to a subject, the pharmaceutical composition comprising a B cell depleting antibody, and / or an anti-CD2 antibody or antigen-binding fragment thereof, the method comprising: a) administering a B cell depleting antibody to said subject; b) administering to said subject an anti-CD2 antibody or antigen-binding fragment thereof; c) transplanting said organ or said tissue into said subject; and d) infusing bone marrow cells from the donor into the subject, wherein: (i) the B cell depleting antibody is administered to the subject more than 7 days prior to the transplant, and / or (ii) the first administration of the anti-CD2 antibody or antigen-binding fragment thereof is one day before the transplant; or (iii) The pharmaceutical composition for said use, wherein the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject more than two days prior to the transplant.

2. 10. The pharmaceutical composition for use according to claim 1, wherein the method further comprises administering fludarabine to the subject, optionally wherein the fludarabine is administered prior to the transplant and / or at a dose of about 10 mg / m ２ The pharmaceutical composition for said use, wherein the pharmaceutical composition is administered at a dose of

3. 2. The pharmaceutical composition for use according to claim 1, wherein the method is a method for minimizing chimera migration syndrome and / or transplant rejection.

4. A pharmaceutical composition for use according to any one of claims 1 to 3, comprising (i) the B cell depleting antibody is administered to the subject 9 days prior to the transplant; (ii) the B cell depleting antibody is administered to the subject 9 days and 2 days prior to the transplant; or (iii) the B cell depleting antibody is administered to the subject 9 days and 2 days before the transplant and 5 days and 12 days after the transplant; A pharmaceutical composition for said use.

5. the B cell depleting antibody is rituximab, and / or the B cell depleting antibody is administered at a concentration of about 375 mg / m ２ The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the composition is administered to the subject at a dose of

6. 4. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject one day before, on the day of, and one day after the transplant.

7. 4. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the anti-CD2 antibody or antigen-binding fragment thereof is (i) 6 days before said transplantation, 1 day before said transplantation, the day of said transplantation, and 1 day after said transplantation; or (ii) 6 days before the transplant, 1 day before the transplant, the day of the transplant, 1 day after the transplant, and 6 days after the transplant; A pharmaceutical composition for said use, administered to said subject.

8. 4. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the anti-CD2 antibody is (i) humanized antibodies, (ii) siplizumab, or (iii) a. a heavy chain variable region CDR1 of SEQ ID NO: 3; b. a heavy chain variable region CDR2 of SEQ ID NO: 4; c. a heavy chain variable region CDR3 of SEQ ID NO: 5; d. a light chain variable region CDR1 of SEQ ID NO: 6; e. a light chain variable region CDR2 of SEQ ID NO: 7; f. An antibody comprising a light chain variable region CDR3 of SEQ ID NO: 8; The pharmaceutical composition for the above use,

9. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the anti-CD2 antibody or antigen-binding fragment thereof is administered to the subject at a dose of about 0.6 mg / kg.

10. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the organ or tissue is a kidney.

11. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the subject and / or the donor is a human.

12. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein the injecting of the bone marrow cells is on the same day as the transplanting.

13. A pharmaceutical composition for use according to any one of claims 1 to 3, wherein the method comprises: (i) administering a non-myeloablative conditioning agent to the subject, optionally wherein the non-myeloablative conditioning agent is cyclophosphamide, fludarabine, or a combination thereof; (ii) administering an anti-IL6R antibody to the subject; and / or (iii) administering an immunosuppressant to the subject for up to about 12 months after the transplant; A pharmaceutical composition for said use further comprising:

14. A pharmaceutical composition for use according to any one of claims 1 to 3, wherein the method comprises: (i) providing thymic irradiation to said subject; (ii) administering a steroid to the subject; (iii) administering an immunosuppressant to the subject; and / or (iv) administering mycophenolate mofetil to the subject; A pharmaceutical composition for said use further comprising:

15. The pharmaceutical composition for use according to any one of claims 1 to 3, wherein each dose of the anti-CD2 antibody or antigen-binding fragment thereof administered to the subject comprises the same dose.

Images