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-10611816-B2
Publication Date
2020-04-07
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) that have antigenic specificity for mutated Kirsten rat sarcoma viral oncogene homolog (KRAS) presented in the context of an HLA-Cw*0802 molecule. The TCRs have specificity for the KRAS protein with the G12D mutation and can recognize peptides comprising the mutated KRAS epitope sequence GADGVGKSA or GADGVGKSAL. The invention includes related polypeptides, proteins, nucleic acids encoding the TCRs, recombinant expression vectors, host cells, populations of cells, and pharmaceutical compositions.
The TCRs provided are capable of recognizing mutated KRAS when presented by HLA-Cw8 molecules, including various alleles such as HLA-Cw*0801 through HLA-Cw*0809, with a preference for HLA-Cw*0802. Additionally, one TCR (TRAV12-2/TRBV10-2) also recognizes mutated KRAS presented by HLA-Cw5 molecules, including alleles such as HLA-Cw*0501 through HLA-Cw*0510. The TCRs may comprise variable regions including CDR1, CDR2, and CDR3 sequences as specified by SEQ ID NOs provided in the document, and may have human or murine constant regions, including substituted constant regions with cysteine and hydrophobic amino acid substitutions to enhance pairing and expression.
The invention solves the problem that many cancers expressing mutated KRAS have limited treatment options and generally poor prognosis despite surgery, chemotherapy, and radiation therapy. There is an unmet need for additional treatments for cancers such as pancreatic, colorectal, lung, endometrial, ovarian, and prostate cancers. The inventive TCRs aim to specifically target mutated KRAS on cancer cells, allowing immune-mediated destruction while minimizing toxicity to normal cells, thus offering a novel and effective immunotherapeutic approach for cancers expressing KRAS G12D mutations.
Claims Coverage
The claims cover isolated or purified nucleic acids encoding TCRs, polypeptides, or proteins with specified amino acid sequences that confer specificity to mutated KRAS G12D presented by HLA-Cw8 molecules, as well as recombinant expression vectors, host cells, cell populations, and pharmaceutical compositions comprising these molecules. There are four independent claims related to nucleic acids encoding TCRs or polypeptides and proteins comprising particular sequences.
Isolated nucleic acids encoding TCRs with specific KRAS G12D antigen specificity
The TCR comprises amino acid sequences selected from SEQ ID NOs: 9-14, 17-22, 25-30, or 33-38 that confer antigenic specificity for mutated KRAS G12D presented by HLA-Cw*0802. Variants include encoding variable regions SEQ ID NOs: 15-16, 23-24, 31-32, or 39-40.
Nucleic acids encoding TCRs with substituted constant regions
The TCR further comprises murine constant regions (SEQ ID NOs: 46 and 47) with specified amino acid substitutions, including cysteine substitutions that form disulfide bonds to stabilize the TCR alpha and beta chains and hydrophobic amino acid substitutions in the transmembrane domain to enhance expression and pairing.
Nucleic acids encoding TCR polypeptides and proteins
Encoding polypeptides comprising specified CDR sequences or variable regions that specifically bind mutated KRAS G12D, as well as proteins comprising paired first and second polypeptide chains (alpha and beta) with given amino acid sequences (SEQ ID NOs: 9-14, 17-22, 25-30, or 33-38 and corresponding variable regions).
Recombinant expression vectors and host cells
Recombinant expression vectors comprising the nucleic acids encoding the specified TCRs, and host cells comprising these vectors for expression of the TCRs, enabling use in therapeutic and diagnostic contexts.
In summary, the claims cover isolated nucleic acids encoding TCRs, polypeptides, or proteins characterized by specific sequences that recognize the mutated KRAS G12D peptide in the context of HLA-Cw*0802 or similar alleles, recombinant vectors, host cells expressing these TCRs, and pharmaceutical compositions incorporating these materials for cancer detection and therapy.
Stated Advantages
The inventive TCRs specifically target mutated KRAS expressed by cancer cells but not by normal cells, minimizing or eliminating toxicity associated with targeting normal tissue.
They may successfully treat or prevent mutated KRAS-positive cancers that are resistant to conventional treatments such as chemotherapy, surgery, or radiation.
The TCRs provide highly avid recognition of mutated KRAS, enabling detection and targeting of unmanipulated tumor cells without prior treatment.
Recognition of mutated KRAS in the context of the HLA-Cw*0802 allele expands the number of immunotherapy-eligible patients, particularly in American Caucasian and African American ethnicities which express this allele at significant frequencies.
Documented Applications
Detection of the presence of cancer in a mammal by contacting a sample with the inventive TCRs or host cells expressing them, and detecting complexes formed with mutant KRAS.
Treatment or prevention of cancer in a mammal by administering pharmaceutical compositions comprising the TCRs, polypeptides, proteins, nucleic acids, recombinant vectors, or host cells expressing the TCRs to mediate immune responses against KRAS G12D mutant cancer cells.
Adoptive cell transfer therapies using T cells genetically engineered to express the inventive TCRs to treat metastatic and unresectable cancers bearing KRAS G12D mutations.
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