Bi-specific T-cell engager (BiTE) is a class of artificial bispecific monoclonal antibodies that are investigated for use as anti-cancer drugs. They direct a host's immune system, more specifically the T cells' cytotoxic activity, against cancer cells. BiTE is a registered trademark of Micromet AG (fully owned subsidiary of Amgen Inc). [1]
BiTE molecules are fusion proteins consisting of two single-chain variable fragments (scFvs) of different antibodies, or amino acid sequences from four different genes, on a single peptide chain of about 55 kilodaltons. One of the scFvs binds to T cells via the CD3 receptor, and the other to a tumor cell via a tumor specific molecule. [2] [3]
Like other bispecific antibodies, and unlike ordinary monoclonal antibodies, BiTEs form a link between T cells and tumor cells. This causes T cells to exert cytotoxic activity on tumor cells by producing proteins like perforin and granzymes, independently of the presence of MHC I or co-stimulatory molecules. These proteins enter tumor cells and initiate the cell's apoptosis. [2] [4]
This action mimics physiological processes observed during T cell attacks against tumor cells. [4]
Several BiTEs are currently in preclinical and clinical trials to assess their therapeutic efficacy and safety. [5]
Blinatumomab links T cells with CD19 receptors found on the surface of B cells. The Food and Drug Administration (US) and the European Medicines Agency approved this therapy for adults with Philadelphia chromosome-negative relapsed or refractory acute lymphoblastic leukemia. [6]
It is a bispecific CD20-directed CD3 T-cell engager. It was approved for medical use in Canada in March 2023, in the United States in June 2023, and in the European Union in July 2023.
Bispecifically binds CD20 and CD3 to engage T-cells. Mosunetuzumab was approved for medical use in the European Union in June 2022.
Solitomab links T cells with the EpCAM antigen which is expressed by colon, gastric, prostate, ovarian, lung, and pancreatic cancers. [7] [8]
Talquetamab, sold under the brand name Talvey, is a humanized monoclonal antibody used for the treatment of multiple myeloma. [9] [10] It is a bispecific GPRC5D-directed CD3 T-cell engager. [9] Talquetamab is a bispecific antibody against two targets: human CD3, a T-cell surface antigen, and human G-protein coupled receptor family C group 5 member D (GPRC5D), a tumor-associated antigen with potential antineoplastic activity. [11] Talquetamab binds both targets, drawing the T cells close to the tumor cells, causing a cytotoxic T-lymphocyte response. [11] It is being developed by Janssen Pharmaceuticals. [12]
The most common adverse reactions include cytokine release syndrome, dysgeusia, nail disorder, musculoskeletal pain, skin disorder, rash, fatigue, decreased weight, dry mouth, pyrexia, xerosis, dysphagia, upper respiratory tract infection, and diarrhea. [13]
Talquetamab was approved for medical use in both the United States [9] [13] [14] and the European Union [15] in August 2023. The US Food and Drug Administration (FDA) considers it to be a first-in-class medication. [16]Tarlatamab, sold under the brand name Imdelltra, is an anti-cancer medication used for the treatment of extensive-stage small cell lung cancer. [17] It is a bispecific T-cell engager that binds delta-like ligand 3 and CD3. [17]
The most common adverse reactions include cytokine release syndrome, fatigue, pyrexia, dysgeusia, decreased appetite, musculoskeletal pain, and constipation, anemia and nausea. [18]
It was approved for medical use in the United States in May 2024. [18] [19]After clinical trials, in January 2022, the US FDA approved tebentafusp (a BiTE targeting the gp100 peptide) for HLA-A*02:01-positive adult patients with unresectable or metastatic uveal melanoma. [20]
Utilizing the same technology, melanoma (with MCSP specific BiTEs) and acute myeloid leukemia (with CD33 specific BiTEs) can be targeted. [21] As of 2008 [update] , research in this area is active. [21]
Another avenue for novel anti-cancer therapies is re-engineering some of the currently used conventional antibodies like trastuzumab (targeting HER2/neu), cetuximab and panitumumab (both targeting the EGF receptor), using the BiTE approach. [22]
As of 2009 [update] , BiTEs against CD66e and EphA2 are being developed as well. [23]
In biology, chimeric antigen receptors (CARs)—also known as chimeric immunoreceptors, chimeric T cell receptors or artificial T cell receptors—are receptor proteins that have been engineered to give T cells the new ability to target a specific antigen. The receptors are chimeric in that they combine both antigen-binding and T cell activating functions into a single receptor.
Cancer immunotherapy (immuno-oncotherapy) is the stimulation of the immune system to treat cancer, improving the immune system's natural ability to fight the disease. It is an application of the fundamental research of cancer immunology (immuno-oncology) and a growing subspecialty of oncology.
Targeted therapy or molecularly targeted therapy is one of the major modalities of medical treatment (pharmacotherapy) for cancer, others being hormonal therapy and cytotoxic chemotherapy. As a form of molecular medicine, targeted therapy blocks the growth of cancer cells by interfering with specific targeted molecules needed for carcinogenesis and tumor growth, rather than by simply interfering with all rapidly dividing cells. Because most agents for targeted therapy are biopharmaceuticals, the term biologic therapy is sometimes synonymous with targeted therapy when used in the context of cancer therapy. However, the modalities can be combined; antibody-drug conjugates combine biologic and cytotoxic mechanisms into one targeted therapy.
Ipilimumab, sold under the brand name Yervoy, is a monoclonal antibody medication that works to activate the immune system by targeting CTLA-4, a protein receptor that downregulates the immune system.
A bispecific monoclonal antibody is an artificial protein that can simultaneously bind to two different types of antigen or two different epitopes on the same antigen. Naturally occurring antibodies typically only target one antigen. BsAbs can be manufactured in several structural formats. BsAbs can be designed to recruit and activate immune cells, to interfere with receptor signaling and inactivate signaling ligands, and to force association of protein complexes. BsAbs have been explored for cancer immunotherapy, drug delivery, and Alzheimer's disease.
Blinatumomab, sold under the brand name Blincyto, and known informally as blina, is a biopharmaceutical medication used as a second-line treatment for Philadelphia chromosome-negative relapsed or refractory acute lymphoblastic leukemia. It belongs to a class of constructed monoclonal antibodies, bi-specific T-cell engagers (BiTEs), that exert action selectively and direct the human immune system to act against tumor cells. Blinatumomab specifically targets the CD19 antigen present on B cells. In December 2014, it was approved by the US Food and Drug Administration under the accelerated approval program; marketing authorization depended on the outcome of clinical trials that were ongoing at the time of approval. Blinatumomab is given via intravenous infusion.
Siltuximab (INN), sold under the brand name Sylvant, is used for the treatment of people with multicentric Castleman's disease. It is a chimeric monoclonal antibody that binds to interleukin-6. It is an interleukin-6 (IL-6) antagonist.
A trifunctional antibody is a monoclonal antibody with binding sites for two different antigens, typically CD3 and a tumor antigen, making it a type of bispecific monoclonal antibody. In addition, its intact Fc-part can bind to an Fc receptor on accessory cells like conventional monospecific antibodies. The net effect is that this type of drug links T cells and monocytes/macrophages, natural killer cells, dendritic cells or other Fc receptor expressing cells to the tumor cells, leading to their destruction.
Patrick Baeuerle is a German-based molecular biologist, immunologist, professor and a biopharmaceutical entrepreneur. Baeuerle is known for his work on tyrosine sulfation of proteins, transcription factor NF-kappaB, and the development of bispecific T-cell engaging antibodies for therapy of cancer.
Daratumumab, sold under the brand name Darzalex among others, is an anti-cancer monoclonal antibody medication. It binds to CD38, which is overexpressed in multiple myeloma cells. Daratumumab was originally developed by Genmab, but it is now being jointly developed by Genmab along with the Johnson & Johnson subsidiary Janssen Biotech, which acquired worldwide commercialization rights to the drug from Genmab.
Nivolumab, sold under the brand name Opdivo, is an anti-cancer medication used to treat a number of types of cancer. This includes melanoma, lung cancer, malignant pleural mesothelioma, renal cell carcinoma, Hodgkin lymphoma, head and neck cancer, urothelial carcinoma, colon cancer, esophageal squamous cell carcinoma, liver cancer, gastric cancer, and esophageal or gastroesophageal junction cancer. It is administered intravenously.
Solitomab is an artificial bispecific monoclonal antibody that is being investigated as an anti-cancer drug. It is a fusion protein consisting of two single-chain variable fragments (scFvs) of different antibodies on a single peptide chain of about 55 kilodaltons. One of the scFvs binds to T cells via the CD3 receptor, and the other to EpCAM as a tumor antigen against gastrointestinal, lung, and other cancers.
Pembrolizumab, sold under the brand name Keytruda, is a humanized antibody, more specifically a PD-1 Inhibitor, used in cancer immunotherapy that treats melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma, stomach cancer, cervical cancer, and certain types of breast cancer. It is administered by slow intravenous injection.
ImmTACs are a class of bispecific biological drug being investigated for the treatment of cancer and viral infections which combines engineered cancer-recognizing TCRs with immune activating complexes. ImmTACs target cancerous or virally infected cells through binding human leukocyte antigen (HLA) presented peptide antigens and redirect the host's cytotoxic T cells to recognise and kill them.
Selinexor sold under the brand name Xpovio among others, is a selective inhibitor of nuclear export used as an anti-cancer medication. It works by blocking the action of exportin 1 and thus blocking the transport of several proteins involved in cancer-cell growth from the cell nucleus to the cytoplasm, which ultimately arrests the cell cycle and leads to apoptosis. It is the first drug with this mechanism of action.
Mosunetuzumab, sold under the brand name Lunsumio, is a monoclonal antibody used for the treatment of follicular lymphoma. It bispecifically binds CD20 and CD3 to engage T-cells. It was developed by Genentech.
Teclistamab, sold under the brand name Tecvayli, is a human bispecific monoclonal antibody used for the treatment of relapsed and refractory multiple myeloma. It is a bispecific antibody that targets the CD3 receptor expressed on the surface of T-cells and B-cell maturation antigen (BCMA), which is expressed on the surface of malignant multiple myeloma B-lineage cells.
Talquetamab, sold under the brand name Talvey, is a humanized monoclonal antibody used for the treatment of multiple myeloma. It is a bispecific GPRC5D-directed CD3 T-cell engager. Talquetamab is a bispecific antibody against two targets: human CD3, a T-cell surface antigen, and human G-protein coupled receptor family C group 5 member D (GPRC5D), a tumor-associated antigen with potential antineoplastic activity. Talquetamab binds both targets, drawing the T cells close to the tumor cells, causing a cytotoxic T-lymphocyte response. It is being developed by Janssen Pharmaceuticals.
Elranatamab, sold under the brand name Elrexfio, is a medication used for the treatment of multiple myeloma. Elranatamab is a bispecific B-cell maturation antigen (BCMA)-directed CD3 T-cell engager. Elranatamab is given by subcutaneous injection.
Tarlatamab, sold under the brand name Imdelltra, is an anti-cancer medication used for the treatment of extensive-stage small cell lung cancer. It is a bispecific T-cell engager that binds delta-like ligand 3 and CD3.