Anti-KRAS-G12D T cell receptors
Inventors
Tran, Eric • Lu, Yong-Chen • Pasetto, Anna • Robbins, Paul F. • Rosenberg, Steven A. • Zheng, Zhili
Assignees
US Department of Health and Human Services
Publication Number
US-11840561-B2
Publication Date
2023-12-12
Expiration Date
2037-07-31
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Abstract
Disclosed is an isolated or purified T cell receptor (TCR) having antigenic specificity for mutated Kirsten rat sarcoma viral oncogene homolog (KRAS) presented in the context of an HLA-Cw*0802 molecule. Related polypeptides and proteins, as well as related nucleic acids, recombinant expression vectors, host cells, populations of cells, and pharmaceutical compositions are also provided. Also disclosed are methods of detecting the presence of cancer in a mammal and methods of treating or preventing cancer in a mammal.
Core Innovation
The invention provides isolated or purified T cell receptors (TCRs) having antigenic specificity for mutated Kirsten rat sarcoma viral oncogene homolog (KRAS) with a G12D mutation, specifically when presented in the context of an HLA-Cw*0802 molecule. These TCRs comprise amino acid sequences of specified SEQ ID NOs and may include functional portions and variants thereof. Related compositions include polypeptides, proteins, nucleic acids, recombinant expression vectors, host cells, populations of cells, and pharmaceutical compositions associated with these TCRs.
The TCRs can specifically recognize mutated KRAS epitopes of various peptide lengths containing the G12D mutation and elicit an immune response upon binding mutated KRAS presented by HLA-Cw*0802 or, in certain cases, HLA-Cw*0501 molecules. The TCRs may include chimeric constructs with human variable regions and murine constant regions, with substitutions that enhance expression, diminish mispairing with endogenous TCRs, and increase anti-tumor activity. Functional variants retaining biological activity are encompassed by the invention.
The problem being addressed is the limited treatment options for cancers, especially metastatic and unresectable cancers, such as pancreatic, colorectal, lung, endometrial, ovarian, and prostate cancers, which may have poor prognoses despite advances in surgery, chemotherapy, and radiation. There exists an unmet need for additional treatments that specifically target cancer cells with minimized toxicity. The invention aims to provide TCRs targeting mutated KRAS to overcome these limitations by facilitating targeted immunotherapy.
Claims Coverage
The claims define multiple inventive features related to isolated or purified peripheral blood mononuclear cells (PBMCs) and T cells expressing TCRs with specific amino acid sequences, addressing TCR compositions at high sequence identity levels, variant constant regions, and methods of treating KRAS G12D-expressing cancers using such T cells.
TCR compositions with defined variable regions at high sequence identity
Claims include isolated or purified PBMCs comprising a nucleic acid encoding TCRs with amino acid sequences at least 99% identical to SEQ ID NOs: 15 and 16; 23 and 24; 31 and 32; or 39 and 40, or their specified subsequences (amino acids 20-129, 22-133, etc.). The claims cover full or partial variable regions of α and β chains.
TCRs with substituted constant regions including cysteine and hydrophobic amino acid substitutions
Claims cover TCRs comprising an amino acid sequence at least 99% identical to SEQ ID NO: 46 with specified variable residues at positions 48, 112, 114, and 115, combined with an amino acid sequence at least 99% identical to SEQ ID NO: 47 with position 57 as Ser or Cys. This includes specified substitutions designed to enhance stability and expression.
TCR compositions comprising specified full-length α and β chains at high sequence identity
Claims cover PBMCs with nucleic acids encoding polypeptides comprising amino acid sequences at least 99% identical to SEQ ID NOs: 50 and 51; 52 and 53; 54 and 55; or 56 and 57, including specified subsequences (amino acids 20-266, 22-306, etc.). Both full and partial sequences are covered.
Utilization of PBMCs and T cells expressing the claimed TCRs
Claims include isolated or purified PBMCs, preferably T cells or CD8+ T cells, expressing the claimed TCRs and populations of such cells. Methods of treatment involving administration of the cell populations, whether autologous or allogeneic, to treat KRAS G12D-expressing cancers are claimed.
The claims collectively cover isolated or purified PBMCs expressing TCRs specifically engineered to recognize KRAS G12D mutations with defined variable and constant region compositions, variants at high sequence identity, inclusion of murine constant regions with particular substitutions, and methods of treating KRAS G12D-expressing cancers by administering these cells.
Stated Advantages
The inventive TCRs specifically target mutated KRAS expressed by cancer cells while minimizing or eliminating destruction of normal non-cancerous cells, thereby reducing toxicity.
They can successfully treat or prevent mutated KRAS-positive cancers that do not respond to chemotherapy, surgery, or radiation.
The TCRs provide highly avid recognition of mutated KRAS, enabling recognition of unmanipulated tumor cells.
The targeting of mutated KRAS in the context of HLA-Cw*0802 increases the number of immunotherapy-eligible patients, particularly among American Caucasian and African American ethnicities carrying this allele.
Documented Applications
Methods of detecting the presence of cancer in a mammal using the inventive TCRs, polypeptides, proteins, nucleic acids, recombinant expression vectors, host cells, populations of cells, or pharmaceutical compositions.
Methods of treating or preventing cancer in a mammal by administering the inventive TCRs, polypeptides, proteins, nucleic acids, recombinant expression vectors, host cells, or populations of cells in an effective amount.
Adoptive cell transfer immunotherapy using host cells genetically modified to express the inventive TCRs to target mutated KRAS-expressing cancers.
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