Methods, compositions, and kits for the selective activation of protoxins through combinatorial targeting

Patent metadata

Field	Value
Publication number	US-8993295-B2
Application number	US-37461607-A
Country	US
Kind code	B2
Filing date	Jul 20, 2007
Priority date	Jul 20, 2006
Publication date	Mar 31, 2015
Grant date	Mar 31, 2015

Abstract

The present invention provides methods and compositions for treating various diseases through selective killing of targeted cells using a combinatorial targeting approach. The invention features protoxin fusion proteins containing a cell targeting moiety and, a modifiable activation moiety which is activated by an activation moiety not naturally operably found in, on, or in the vicinity of a target cell. These methods also include the combinatorial use of two or more therapeutic agents, at minimum comprising a protoxin and a protoxin activator, to target and destroy a specific cell population.

First claim

What is claimed is:

1. A composition comprising;
(i) a protoxin fusion protein comprising a first non-native cell-targeting moiety, a selectively modifiable activation domain and a toxin domain; and a
(ii) protoxin activator fusion protein comprising a second non-native cell-targeting moiety and a modification domain;

wherein:
said first cell-targeting moiety of said protoxin fusion protein and said second cell-targeting moiety of said protoxin activator fusion protein each recognize and bind a common target cell;
said modification domain comprises protease or phosphatase enzymatic activity exogenous to said target cell;
said selectively modifiable activation domain comprises a substrate for said modification domain; and
modification of said selectively modifiable activation domain by said modification domain results in activation of said toxin domain.

2. The composition of claim 1 , wherein said enzymatic activity is protease activity.

3. The composition of claim 1 , wherein said modification domain is a phosphatase and said modifiable activation domain comprises phosphorylation of a protease cleavage site.

4. The composition of claim 1 , wherein at least one non-native cell-targeting moiety is an artificially diversified binding protein.

5. The composition of claim 1 , wherein said protoxin is an activatable toxin.

6. The composition of claim 5 , wherein said activatable toxin is selected from the group consisting of an activatable pore forming toxin or an activatable enzymatic toxin.

7. The composition of claim 1 , wherein said toxin domain is selected from a group consisting of an AB toxin, a cyotoxic necrotizing factor toxin, a dermonecrotic toxin, and an activatable ADP-ribosylating toxin.

8. The composition of claim 1 , wherein said toxin domain is selected from a group consisting of aerolysin, Vibrio cholerae exotoxin, Pseudomonas exotoxin and diphtheria toxin.

9. The composition of claim 1 , wherein said protoxin activator fusion protein further comprises a natively activatable domain wherein said modification domain is inactive prior to activation of said natively activatable domain and, when active, is non-toxic to a target cell.

10. The composition of claim 1 , wherein said modification domain is a protease domain.

11. The composition of claim 10 , wherein said protease domain is the catalytic domain of a non-human protease.

12. The composition of claim 11 , wherein said non-human protease is a viral protease.

13. The composition of claim 1 , wherein said non-native cell-targeting moiety recognizes a cancer cell.

14. The composition of claim 1 , wherein at least one non-native cell-targeting moiety is an antibody or antibody fragment.

15. The composition of claim 1 , wherein both of said cell-targeting moieties is an antibody or antibody fragment.

16. The composition of claim 10 , wherein said protease domain is the catalytic domain of an exogenous human protease.

17. A composition comprising:
(i) a protoxin fusion protein comprising a first non-native cell-targeting moiety, a selectively modifiable activation domain and a toxin domain; and a
(ii) protoxin activator fusion protein comprising a second non-native cell-targeting moiety and a modification domain;

wherein:
said first cell-targeting moiety of said protoxin fusion protein and said second cell-targeting moiety of said protoxin activator fusion protein each recognize and bind a common target cell;
said modification domain comprises enzymatic activity exogenous to said target cell;
said selectively modifiable activation domain comprises a substrate for said modification domain; and

modification of said selectively modifiable activation domain by said modification domain results in proteolytic cleavage and activation of said toxin domain.

Assignees

• Seed Brian
• Wolfe Jia Liu
• Cho Glen S
• Tsai Chia-Iun
• Gen Hospital Corp

Inventors

• Seed Brian
• Wolfe Jia Liu
• Cho Glen S
• Tsai Chia-Iun

Classifications

• A61P7/06

  Antianaemics · CPC title

• A61P35/02

  specific for leukemia · CPC title

• A61P37/08

  Antiallergic agents (antiasthmatic agents A61P11/06; ophthalmic antiallergics A61P27/14) · CPC title

• A61P3/10

  for hyperglycaemia, e.g. antidiabetics · CPC title

• A61P43/00

  Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00 · CPC title