Multivalent CD20-binding molecules comprising Shiga toxin a subunit effector regions and enriched compositions thereof
The present invention provides multivalent CD20-binding molecules and compositions thereof, such as enriched compositions comprising large proportions of multivalent CD20-binding molecules relative to monovalent CD20-binding molecules. Certain multivalent CD20-binding molecules of the present invention comprise (i) two or more CD20-binding regions and (ii) one or more Shiga toxin effector polypeptide regions derived from an A Subunit of a member of the Shiga toxin family. Certain multivalent CD20-binding molecules of the present invention, and compositions thereof, have uses for selective killing of specific cell types and as therapeutics for the treatment of a variety of diseases, including cancers, tumors, and immune disorders. Certain multivalent CD20-binding molecules of the present invention, and compositions thereof, have uses for delivering agents into CD20-expressing cells, collecting diagnostic information, and monitoring the treatment of a variety of diseases, such as cancers, tumors, and immune disorders which involve CD20-expressing cells.
1. A method of killing a cell that expresses human CD20 at a cellular surface, the method comprising: contacting the cell with a composition comprising:
(a) a cytotoxic multivalent CD20-binding molecule, wherein the multivalent CD20-binding molecule is multimeric and comprises at least two polypeptides linked by at least one covalent bond, each of the polypeptides having at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 54 and/or SEQ ID NO: 55, and
(b) a monovalent CD20-binding molecule consisting of a polypeptide having at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 54 or SEQ ID NO:55, wherein the ratio of the monovalent CD20-binding molecule concentration to the total CD20-binding molecule concentration is less than 1:5, thereby killing the cell.
2. The method of claim 1 , wherein the ratio of the monovalent CD20-binding molecule concentration to the total CD20-binding molecule concentration is less than 1:11.
3. The method of claim 1 , wherein the cytotoxic multivalent CD20-binding molecule is a dimer.
4. The method of claim 1 , wherein the cytotoxic multivalent CD20-binding molecule is a homodimer.
5. The method of claim 1 , wherein the cytotoxic multivalent CD20-binding molecule is a homodimer consisting of two identical polypeptides linked by at least one covalent bond, each having the amino acid sequence of SEQ ID NO: 54.
6. The method of claim 1 , wherein the cytotoxic multivalent CD20-binding molecule is a homodimer consisting of two identical polypeptides linked by at least one covalent bond, each having the amino acid sequence of SEQ ID NO: 55.
7. The method of claim 4 , wherein the ratio of dimeric cytotoxic CD20-binding molecule concentration to total cytotoxic CD20-binding molecule concentration is greater than 3:4.
8. The method of claim 1 , wherein the cytotoxic multivalent CD20-binding molecule is a higher-order multimer comprising at least three polypeptides, each having at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 54 and/or SEQ ID NO: 55, wherein at least two of the at least three polypeptides are linked by at least one covalent bond.
9. The method of claim 8 , wherein the cytotoxic multivalent CD20-binding molecule is a homomultimer comprising at least three identical polypeptides, each having at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 54 or SEQ ID NO: 55, wherein at least two of the at least three polypeptides are linked by at least one covalent bond.
10. The method of claim 3 , wherein the composition further comprises a cytotoxic multivalent CD20-binding molecule that is a higher-order multimer comprising at least three polypeptides, each having at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 54 and/or SEQ ID NO:55,
wherein at least two of the at least three polypeptides are linked by at least one covalent bond, and
wherein the ratio of the higher-order multimer CD20-binding molecule concentration to total CD20-binding molecule concentration is less than 1:4.
11. The method of claim 1 , wherein the at least one covalent bond comprises a disulfide bond.
12. The method of claim 1 , wherein administration of the composition to a first population of cells whose members are CD20 positive, and a second population of cells whose members are not CD20 positive, a cytotoxic effect of the composition to members of the first population of cells relative to the second population of cells is at least 3-fold greater.
13. The method of claim 1 , wherein the contacting occurs in vitro.
14. The method of claim 1 , wherein the contacting occurs in vivo.
15. A method of treating a CD20-expressing cancer or an immune disorder involving CD20-expressing cells in a patient in need thereof, comprising administering to the patient a therapeutically effective amount of a composition comprising:
(a) a cytotoxic multivalent CD20-binding molecule, wherein the multivalent CD20-binding molecule is multimeric and comprises at least two polypeptides linked by at least one covalent bond, each of the polypeptides having at least 98% sequence identity to the amino acid sequence selected from SEQ ID NO: 54 and SEQ ID NO: 55, and
(b) a monovalent CD20-binding molecule consisting of a polypeptide having at least 98% sequence identity to the amino acid sequence of SEQ ID NO: 54 or SEQ ID NO:55,
wherein the ratio of the monovalent CD20-binding molecule concentration to the total CD20-binding molecule concentration is less than 1:5, thereby treating the cancer or the immune disorder in the patient.
16. The method of claim 15 , wherein the composition further comprises at least one of: a pharmaceutically acceptable excipient, a carrier, a vehicle, an aqueous carrier, a non-aqueous carrier, a solvent, a buffer, an alcohol, a polyol, an antioxidant, an antimicrobial agent, an isotonic agent, a surfactant, a chelating agent, a stabilizer, an adjuvant, a preservative, a wetting agent, an emulsifying agent, a dispersing agent, a dispersion medium, a coating, and/or an adsorption delaying agent.
17. The method of claim 15 , wherein the composition further comprises a pharmaceutically acceptable excipient or carrier.
18. The method of claim 17 , wherein the pharmaceutically acceptable excipient or carrier comprises at least one of: acetate, alcohol, alpha-tocopherol, aluminum monostearate, ascorbic acid, ascorbyl palmitate, benzyl alcohol, butylated hydroxyanisole, butylated hydroxytoluene, chlorobutanol, citrate, cysteine hydrochloride, dextrose, ethanol, ethyelenediaminetetraacetic acid, ethyloleate, gelatin, glycerine, glycerol, lactic acid, lecithin, mannitol, methyl parabens, monostearate salt, organic ester, paraben, phosphate, phosphoric acid, polyalcohol, polyethylene glycol, polyol, propylene glycol, propylgallate, Ringer's solution, saline, sodium bisulfate, sodium bisulfite, sodium chloride, sodium metabisulfite, sodium sulfite, sorbitol, sugar, tartaric acid and/or water.