# US 5,705,156 A · Psuedomonas exotoxins of low animal toxicity and high cytocidal activity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,705,156 A - Document ID: US5705156A - Status: Granted - Kind: A - Application number: 08/467,264 - Filed: 1995-06-06 - Granted: 1998-01-06 - Earliest claimed: 1990-05-11 - Assignees: The United States of America, as represented by the Secretary, Department of Health and Human Services - Inventors: Ira Pastan; David Fitzgerald; Vijay K. Chaudhary - Web page: https://patentgrep.com/patent/US5705156A ## CPC - C07K 14/70514: {CD4} - A61P 35/00: Antineoplastic agents - A61P 43/00: Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00 - C07K 14/21: from Pseudomonadaceae (F) - C07K 14/495: Transforming growth factor [TGF] - C07K 14/5412: {IL-6} - A61K 38/00: Medicinal preparations containing peptides (peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00) - C07K 2319/00: Fusion polypeptide - C07K 2319/02: containing a signal sequence - C07K 2319/034: containing a motif for targeting to the periplasmic space of Gram negative bacteria as a soluble protein, i.e. signal sequence should be cleaved - C07K 2319/55: containing a fusion with a toxin, e.g. diphteria toxin - C07K 2319/75: containing a fusion for activation of a cell surface receptor, e.g. thrombopoeitin, NPY and other peptide hormones - Y10S 435/875: Pseudomonas aeruginosa - C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00) - A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Improved Pseudomonas exotoxins of low animal toxicity and high cytocidal activity are described. Substitution of positively charged amino acid residues with an amino acid residue without a positive charge provides markedly changed exotoxins. Conjugation of the new exotoxins with suitable targeting agents provides cytocidal specificity for killing desired cellular entities. ## Claims ### Claim 1 A method of killing cells, said method comprising contacting said cells with a cytocidal amount of a modified Pseudomonas exotoxin (PE) attached to a targeting agent that binds to a specific site on said cells, said modified PE having at least one positively charged amino acid in domain 1a substituted by an amino acid without a positive charge so the modified PE has a lower animal toxicity compared to a PE lacking the substitution, said modified PE being selected from the group consisting of a PE in which each of the amino acids numbered 57, 246, 247 and 249 is glutamic acid (PE-Glu-57, 246, 247, 249), a PE in which amino acid 57 is a glutamic acid and amino acids 241-250 are deleted (PE-Glu-57.DELTA.241-250), and a PE in which amino acid 57 is a glutamic acid and each of the amino acids numbered 246, 247, and 249 is glycine (PE-Glu-57-Gly 246, 247, 249). ### Claim 2 (depends on 1) The method of claim 1, wherein at least three positively charged amino acids are substituted. ### Claim 3 (depends on 1) The method of claim 1, wherein said modified PE has a positively charged amino acid at position 57 or between positions 246 and 249 in domain 1a substituted by an amino acid without a positive charge. ### Claim 4 (depends on 2) The method of claim 2, wherein the amino acid without a positive charge is glutamic acid or glycine. ### Claim 5 (depends on 1) The method of claim 1, wherein said targeting agent is an antibody or an antigen binding fragment thereof. ### Claim 6 (depends on 1) The method of claim 1, wherein said targeting agent is a peptide hormone. ### Claim 7 (depends on 1) The method of claim 1, wherein said targeting agent is a growth factor. ### Claim 8 (depends on 1) The method of claim 1, wherein said targeting agent is a cytokine. ### Claim 9 (depends on 1) The method of claim 1, wherein said targeting agent is an antigen. ### Claim 10 (depends on 1) The method of claim 1, wherein said targeting agent is a receptor. ### Claim 11 (depends on 1) The method of claim 1, wherein said targeting agent is IL6. ### Claim 12 (depends on 1) The method of claim 1, wherein said targeting agent is TGF.alpha.. ### Claim 13 (depends on 1) The method of claim 1, wherein said targeting agent is CD4.