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-11897933-B2
Publication Date
2024-02-13
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
This invention provides isolated or purified T cell receptors (TCRs) that specifically recognize mutated Kirsten rat sarcoma viral oncogene homolog (KRAS), particularly the KRAS protein with the G12D mutation, when presented by an HLA-Cw*0802 molecule. The TCRs include variable and complementarity determining regions (CDRs) with defined amino acid sequences, as well as chimeric variants with human or murine constant regions, including cysteine-substituted and hydrophobic amino acid-substituted forms to enhance expression and reduce mispairing. The invention also covers related polypeptides, proteins, nucleic acids, recombinant expression vectors, host cells, populations of cells, and pharmaceutical compositions, alongside methods for detecting cancer presence and treating or preventing cancer in mammals using these inventive TCR materials.
The problem addressed by the invention is the limited treatment options for cancers, especially metastatic and unresectable forms, such as pancreatic, colorectal, lung, endometrial, ovarian, and prostate cancers. Conventional treatments including surgery, chemotherapy, and radiation often result in poor prognosis. There is an unmet need for novel therapies that target cancer cells selectively and effectively, especially those that express mutated KRAS, which is implicated in oncogenesis through constitutive activation and signal transduction.
The inventive TCRs specifically recognize the mutated KRAS G12D epitope within the context of certain HLA alleles, primarily HLA-Cw*0802, and one TCR also recognizes mutated KRAS within the context of HLA-Cw*0501. The TCRs elicit immune responses such as IFN-γ secretion and T-cell activation upon contact with antigen-presenting cells displaying the mutated KRAS peptide. The invention substantially allows targeting of cancer cells expressing mutated KRAS with reduced off-target effects, potentially enabling treatment of cancers refractory to existing therapies.
Claims Coverage
The patent claims cover multiple independent embodiments of nucleic acids encoding TCRs with specific amino acid sequence identities, recombinant expression vectors, host cells, cell populations, and methods of treating KRAS G12D-expressing cancers.
Nucleic acids encoding TCRs with specified variable regions
An isolated or purified nucleic acid comprises a nucleotide sequence encoding a TCR having amino acid sequences at least 99% identical to specified variable regions of SEQ ID NOs: 15 and 16, 23 and 24, 31 and 32, or 39 and 40, including defined amino acid subranges for these sequences.
TCRs with substituted murine constant regions
The TCRs further comprise murine constant regions with specified amino acid substitutions at defined positions (SEQ ID NOs: 46 and 47), including cysteine substitutions enabling disulfide bond formation, enhancing TCR pairing and expression.
Full-length TCRs with paired alpha and beta chains
Nucleic acids encoding full-length TCR alpha and beta chains 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 amino acid subranges.
Recombinant expression vectors and host cells
The invention includes recombinant expression vectors comprising the nucleic acids encoding these TCRs, isolated or purified host cells or populations of cells comprising such vectors or nucleic acids, and pharmaceutical compositions containing these cells.
Methods of treating KRAS G12D-expressing cancer
Methods involve administering the host cells, cell populations, or pharmaceutical compositions expressing these TCRs in an effective amount to treat a mammal with cancer expressing the KRAS G12D mutation.
The claims comprehensively protect nucleic acids encoding TCRs specific for mutated KRAS G12D with defined amino acid sequences or closely related variants, means to express these TCRs in host cells, and therapeutic methods employing the engineered cells to treat KRAS G12D-expressing cancers.
Stated Advantages
The inventive TCRs selectively target mutated KRAS-expressing cancer cells while minimizing destruction of normal cells, reducing toxicity.
They provide high avidity recognition allowing detection and targeting of unmanipulated tumor cells not artificially treated or modified.
Recognition of mutated KRAS presented by the relatively common HLA-Cw*0802 allele broadens immunotherapy eligibility to more patients, including those not covered by other TCR therapies.
Modified constant regions (murine, cysteine-substituted, hydrophobic amino acid-substituted) enhance TCR expression, reduce mispairing with endogenous TCRs, and increase anti-tumor activity.
Documented Applications
Methods of detecting the presence of cancer in mammals by contacting samples with the inventive TCRs or related materials to detect complexes indicative of cancer.
Methods of treating or preventing cancers in mammals expressing the mutated KRAS G12D, including pancreatic, colorectal, lung, endometrial, ovarian, and prostate cancers, using pharmaceutical compositions comprising host cells expressing the inventive TCRs.
Production of host cells and cell populations expressing said TCRs via recombinant expression vectors for therapeutic use.
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