Human bispecific EGFRvIII antibody and CD3 engaging molecules
Inventors
Bigner, Darell • Kuan, Chien-Tsun • Sampson, John • Choi, Bryan • Pastan, Ira H. • Gedeon, Patrick C.
Assignees
UNITED STATES GOVERNMENT HEALTH AND HUMAN SERVICES (NIH), Secretary of, Department of • Duke University • US Department of Health and Human Services
Publication Number
US-9676858-B2
Publication Date
2017-06-13
Expiration Date
2033-06-07
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Abstract
We have constructed bispecific antibody engaging molecules which have one arm that specifically engages a tumor cell which expresses the human EGFRvIII mutant protein on its surface, and a second arm that specifically engages T cell activation ligand CD3. The engaging molecules are highly cytotoxic and antigen-specific. These may be used as therapeutic agents.
Core Innovation
The invention relates to bispecific antibody engaging molecules designed to treat cancers expressing the EGFRvIII mutant protein. These bispecific polypeptides include one arm that specifically binds to the EGFRvIII antigen found on tumor cells, and a second arm that specifically engages the T cell activation ligand CD3, thereby recruiting and activating cytotoxic T cells to induce tumor cell lysis. The bispecific molecules are constructed from human single chain variable regions derived from sequences encoded by SEQ ID NO: 2, 3 for EGFRvIII binding and SEQ ID NO: 5, 6 for CD3 binding.
The problem addressed by the invention is the persistent fatality of cancers such as glioblastoma multiforme (GBM) despite current treatments including surgery, radiation, and chemotherapy. There is a lack of effective tumor-specific targets commonly and homogeneously expressed on tumors that can be redirected by bispecific T cell engaging molecules for specific immune activation. Specifically, EGFRvIII is a mutant form of EGFR expressed in GBM and other tumors that provides a tumor-specific epitope absent in normal tissues, making it an attractive target for specific therapeutic intervention.
The bispecific polypeptides of this invention allow for selective targeting of EGFRvIII-expressing tumor cells and engagement of T cells to mediate potent antigen-specific cytotoxicity. Methods of making and using the bispecific molecules are provided, including nucleic acids encoding the molecules, recombinant production, and administration to patients to induce cytolytic T cell responses against EGFRvIII-expressing tumors. The molecules may be produced in cells such as CHO or bacteria and harvested from culture. Multiple bispecific antibody formats and linkers may be utilized to optimize function. The invention envisions therapeutic applications against tumors expressing EGFRvIII, including brain tumors such as GBM, breast, and lung cancers.
Claims Coverage
The patent includes three independent claims covering the bispecific polypeptide, nucleic acid encoding the polypeptide, and methods of treatment and production. There are four distinctive inventive features highlighting the structure and use of the bispecific molecules.
Bispecific polypeptide comprising human single chain variable regions binding EGFRvIII and CD3
The invention claims a bispecific polypeptide comprising a first human single chain variable region binding EGFRvIII with segments encoded by SEQ ID NO: 2 and 3, linked in series to a second human single chain variable region binding CD3, with segments encoded by SEQ ID NO: 5 and 6. The polypeptide sequence follows the N-terminal to C-terminal order of segments encoded by SEQ ID NO: 2, 3, 4, 5, and 6.
Polynucleotide encoding the bispecific polypeptide
The invention covers polynucleotides encoding the bispecific polypeptide of the first inventive feature. Specifically, sequences including SEQ ID NO: 8 encode the bispecific molecule disclosed.
Method of treating EGFRvIII-expressing tumors with the bispecific polypeptide
Administering the bispecific polypeptide comprising human single chain variable regions targeting EGFRvIII and CD3 to a patient induces a cytolytic T cell response against EGFRvIII-expressing tumors, effectuating tumor cell lysis and therapeutic benefit.
Method of producing the bispecific polypeptide from cultured cells
Culturing cells containing polynucleotide sequences encoding the bispecific polypeptide in a suitable medium to express and produce the molecule and collecting it from cells or culture medium provides a method to manufacture the bispecific polypeptide for therapeutic use.
The claims collectively define a bispecific molecule formed from human single chain variable regions targeting EGFRvIII and CD3, nucleic acid sequences encoding this molecule, therapeutic methods administering this molecule to treat EGFRvIII-positive tumors, and cell-based production methods enabling recombinant expression and harvesting.
Stated Advantages
The bispecific T cell engaging molecules are highly cytotoxic and antigen-specific to EGFRvIII-expressing tumor cells.
Use of fully human antibodies reduces the likelihood of neutralizing antibody development, enabling repeated administration.
The molecules direct potent and localized T cell activation specifically at tumor sites, potentially enhancing therapeutic efficacy with limited off-target toxicity.
Dose-dependent tumor growth inhibition is demonstrated, supporting therapeutic potential in vivo.
Documented Applications
Treatment of EGFRvIII-expressing tumors including glioblastoma multiforme, breast tumors, and lung tumors.
Use in cancer immunotherapy by inducing cytolytic T cell responses against tumor cells expressing EGFRvIII.
Recombinant production and purification of bispecific polypeptides for therapeutic administration.
Potential incorporation of therapeutic or diagnostic agents linked to the bispecific molecules for targeted delivery to EGFRvIII-expressing cells.
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