Invented by Yang Liu, Pan Zheng, Martin DEVENPORT, Oncoc4 Inc
The Oncoc4 Inc invention works as followsThis invention is a composition of humanized and chimeric antibodies that bind the human CTLA4 molecular and their use for cancer immunotherapy as well as for reducing autoimmune side effects in comparison to other immunotherapeutic drugs.
Background for Chimeric anti-human CTLA4 Monoclonal Antibodies and their Uses
The immune system is the main defense against disease and infection in humans and other mammals. This protection is provided by both a humoral and a cellular immune response. The humoral immune response is characterized by the production of biomolecules and antibodies that can recognize and neutralize foreign targets (antigens). The cell-mediated response is characterized by the activation and release of cytokines and macrophages as well as neutrophils, natural killer (NK) cells and antigen-specific T-lymphocytes.
Two distinct signaling interactions are required for T cells to mediate an optimal immune response against antigens. First, the antigen arrayed onto the surface of the antigen-presenting cell (APC) needs to be presented in the form MHC:peptide complex (1 or 2) to naive antigen-specific T cells. This presentation sends a signal to the TCR that instructs the T cells to initiate an immunological response specific to the antigen presented. The second step is a series co-stimulatory signal, which is mediated by interactions between APCs and different T cell surface molecules. This triggers the first activation, then proliferation, and finally inhibition of T cells (3-5). The first signal is responsible for specificity of the immune response, while the second one determines the magnitude, duration, and nature of the response, while restricting immunity against self. “Among these second signal molecules, the binding between B7.1 (CD80), (6) and B7.2(CD86), (7-9) ligands from the Antigen Presenting Cell with the CD28 and CTLA4 (10)-12 receptors of the T lymphocyte is of particular importance.
Cytotoxic lymphocyte antigen-4, or CTLA4, is recognized as one of the key regulators in adaptive immune responses. It plays a crucial role in maintaining peripheral tolerance, in shaping the repertoire for emerging T-cell responses, and therefore, it can be used therapeutically to treat cancer and inflammation. In preclinical models, treatment with anti-CTLA4 antibody has shown to be an effective tool in enhancing antitumor immune responses (10). “Monotherapy with an anti-CTLA4 antibody promoted rejection of transplantable tumours of different origins.
The clinical potential of antibodies against CTLA4 in human malignancies has been investigated based on promising preclinical studies. Yervoy, marketed under the name Ipilimumab (anti-CTLA4), has shown efficacy against melanoma. However, targeting CTLA4 and treatment of it are associated with autoimmune toxicities. The most common immune-related adverse effects (irAEs), which are caused by CTLA4 inhibition, are skin rash and hepatitis. There is therefore a desire to increase the therapeutic potential for anti-CTLA4 antibody by increasing efficacy and reducing the associated adverse events (irAEs).
The combination of immune check inhibitors is another focus in the field of immunotherapy, especially for tumors that are not immunogenic. This approach, however, is associated with a risk of increasing autoimmune side effects. This further highlights the need to selectively modify cancer immunity without enhancing autoimmune.
Further investigation into the ligands for the CD28 receptor has led to the identification of and characterization of an associated set of B7 molecules. (The?B7 Superfamily?) (32-33). “There are several members of this family that have been identified: B7.1(CD80),B7.2 (CD86), ICOS-L (inducible costimulator-stimulator-ligand), PD-L1 (B7-H1) and PD-L2 (B7-DC), as well as B7H3,B7H4,and B7H6 (35-36)”.
B7H1 is widely expressed in various human and mouse tissues such as the heart, placenta and muscle in both species, as well as in liver, lung and kidney only in mice (37). B7-H1 is a member of the B7 Superfamily that is particularly important as it plays a pivotal role in the immune response against tumors. Nos. 6,803,192; 7,794,710; United States Patent Application Publication Nos. “6,803,192; 7,794,710; United States Patent Application Publication Nos. “WO 01/39722”; “WO 02/086083)”.
Programmed Death-1 (?PD-1?) “Programmed Death-1 (?PD-1?) PD-1 belongs to the extended CD28/CTLA4 T cell regulatory family (39, United States Patent Application Publication Number). 2007/0202100; 2008/0311117; 2009/00110667; U.S. Pat. Nos. Nos. WO 01/14557). PD-1 has a more negative immune response than CTLA4. PD-1 is found on activated B cells, T cells and monocytes (41-41), as well as at low levels on natural killer T cells (42-43).
The interaction between B7-H1 & PD-1 provides a negative co-stimulatory message to T and B cell (43) as well as a cell-death inducer (39). B7-H1 inhibits T cell proliferation and activation, which suggests that these biomolecules could be used as therapeutic targets to treat cancer and inflammation. Anti-PD1 and anti B7-H1 antibody treatment for tumors, infections and to up-modulate adaptive immune responses has been suggested and shown to be effective in the treatment of a variety of human cancers. There are some subjects who do not respond to anti PD-1 or anti B7-H1 treatments. This is why there is a great interest in combining anti PD-1 or anti B7-H1 with other immune-check inhibitors to increase anti-tumor activities.
4-1BB” (also called CD137 or TNFRSF9), is another immune-checkpoint molecule. CD137’s costimulatory action on activated T-cells is best described. Crosslinking CD137 increases T cell proliferation, IL-2 production, survival, and cytolytic activities. Anti-4-1BB antibodies, just like anti-CTLA4, can also enhance immune activity in order to eliminate tumors from mice (27-29). Cancer therapeutic anti-4-1BB antibodies have shown that, unlike anti-CTLA4 antibody’s tendency to exacerbate autoimmune disease, they can abort the development of autoimmune disorders in lupus-prone mice. They inhibited anti dsDNA antibody and reduced renal pathology. Data from previous studies have shown that anti-CTLA4 therapy can reduce the autoimmune effects in a colon cancer model of mice by using anti-4-1BB antibodies. This also increases the anti-tumor effect (19). This shows that the anti-CTLA4 cancer therapy can be offset by reducing its autoimmune side effects.
The preclinical screening of human CTLA4 antibody is difficult because the in vitro immunological correlates can be of limited value as shown by anti-mouse CTLA4 antibody experience. Anti-mouse CTLA4 antibody that induces potent antitumor immunity can have different effects on T-cells in vitro. Anti-CTLA4 antibody increased T cell proliferative response in response to alloantigen but suppressed it in response anti-CD28 costimulation (30, 31). CTLA4 interaction with antibody can either promote or suppress proliferation of different T cell subsets in the same culture (32). This problem can be solved by studying human T-cell responses in a mouse model.
Anti-CTLA4 antibody reduced side effects are described herein when used for anti-tumor treatment and to boost immune responses. These antibodies can also be combined with other checkpoints inhibitors such as anti-PD-1 or anti-4-1BB to increase anti-tumor activity while reducing autoimmune side-effects.
This invention is a composition of antibodies and antigen-binding fractions that binds to the CTLA4 human molecule, and their use in cancer immunotherapy. The side effects are reduced. The invention is a set of antibodies that have enhanced CTLA4 blocking activities for CTLA4 B7.1 and B7.2 ligands, enhanced effector functions, or reduced binding to CTLA4 in soluble form compared to membrane-bound or immobilized CTLA4.
The antibody may contain a light-chain variable amino acidsequence with the amino sequence shown in SEQID NO: 1 and a heavy-chain variable amino acidsequence showing the amino sequence in SEQID NO: 2. The antibody can also contain a heavy-chain variable amino-acid sequence with the amino-acid sequence specified in SEQ NO: 27, 28, or 29, as well as a light-chain variable amino acid sequence with the amino acid sequence specified in SEQ NO: 30, 31, or 32. The antibody can have a light-chain variable region with CDR sequences as set forth by SEQ NOS 21, 22, and 23 and a heavy-chain variable region with CDRs as set forth by SEQ NOS 24, 25, and 26. The antibody can be composed of a heavy-chain variable region with a CDR2 set out in SEQ NO: 33,34 or 35 and a lighter-chain variable region with CDR sequences in SEQ NO: 363738.
The amino acid sequence of SEQ ID No: 3 or 4 may be used in the immunoglobulin heavy chains constant regions. The immunoglobulin-heavy chain constant region may also contain a mutation. The mutation can be any of M135Y (relative to SEQ ID No: 3), S137T, E216A or K217A (or a combination) or S181A. The immunoglobulin constant region of an antibody may contain all six mutations. The antibody can include a heavy-chain amino acid whose sequence is SEQ NO: 6 and a lighter-chain amino acid whose sequence is SEQ NO: 8. The antibody can also include a heavy-chain amino acid chain having an amino acid chain set forth by SEQID NO: 9, 11, or 13 and a lighter-chain amino acid chain having an amino acid chain set forth by SEQID NO: 15, 17, or 19. The antibody can bind human CTLA4. The antibody can also prevent the binding of CTLA4 human to B7-1 and B7-2.
The antigen-binding fragments of the antibodies described in this document are also provided.
Also, herein is provided a pharmaceutical composition containing a therapeutically-effective amount of antibodies described herein.” The pharmaceutical composition can include a physiologically-acceptable carrier or excipient.
In another aspect, the present invention provides methods of enhancing immune functions or responses within a patient, which include administering anti-CTLA4 antibodies and pharmaceutical compositions to a patient in need. In one embodiment, the present invention provides methods for treating or managing a condition in which activating or enhancing immune functions is desired. Cancer is one example of a disease that may include human malignancy. The human malignancy can be, for example, melanoma or lung cancer. It could also be Hodgkin or non-Hodgkin lymphoma. In another embodiment the disease being treated is an infection. The present method may reduce autoimmune side effects associated with immunotherapy.
In other embodiments of the method, combination therapy is used, in which the anti-CTLA4 antibodies described herein are administered as an adjuvant to a patient, along with another therapy that may activate or enhance immune functions or responses. In another embodiment, anti-CTLA4 compositions are administered in combination with antigenic compositions as an adjuvant. In one embodiment, anti-CTLA4 compositions are administered with a vaccine to activate or induce the immune response.
In a specific embodiment the anti-CTLA4 antibodies described herein can be administered to a patient in combination with other therapies targeting different immunomodulatory pathways. In a preferred embodiment the anti-CTLA4 compositions described are synergistic or complementary to the activity of therapy targeting a distinct immunomodulatory path. In some instances, anti-CTLA4 compositions are combined with small oncoimmunological moderators like indoleamine 2,3,-dioxygenase inhibitors. In another instance the anti-CTLA4 compositions described herein can be administered with immune stimulating molecules. Specific embodiments involve combining antiCTLA4 antibodies described herein with antiPD-1 (pembrolizumab or Nivolumab, Opdivo or Tecentriq), antiB7H1 (atezolizumab or durvalumab), antiB7H3, antiB7H4, antiTim3, antiB7H4, antiB7H4, antiB7H3, antiB7H4, antiB7H4, antiB7H4, antiB7H4, antiB7 In another embodiment, anti-CTLA4 antibodies described herein are combined with the second immune-stimulating molecule to form a bi-specific antibody.
In another embodiment, the anti-human CTLA4 antibodies described herein can preferentially bind human CTLA-4 expressed at the cell surface compared to soluble CTLA4 molecule. The anti-human CTLA4 may bind with human CTLA4 to preferentially increase the expression of B7.1 and B7.2. The anti-human CTLA4 antibody can be included in a formulation for modulating immune responses and treating cancer.Click here to view the patent on Google Patents.