Conjugate having cytotoxicity and process for the preparation thereof

Claim 2

A conjugate having cytotoxicity comprising an immunoglobulin, or its fragment, which is capable of selectively binding to a particular antigen possessed by a cell to be killed, and a polymer, which has cytotoxic substances linked to its side chains and a reactive group at its terminal, both being covalently bound to each other.

Claim 3

The conjugate having cytotoxicity according to Claim 1, wherein said conjugate is expressed by the following formula (I) (wherein Ab indicates an immunoglobulin or its fragment capable of binding selectively to a particular antigen possessed by a cell to be killed; B 1 is a divalent organic group; S 1 is a sulfur atom; W is a divalent organic group; R 1 indicates a side chain at the a-position of a-amino acid or its derivative (excluding a group which has a carboxyl group; Y represents a reaction residue of a cytotoxic substance which contains an amino group or an imino group in the molecule; Z indicates a hydrogen atom or a monovalent cation; m is an integer 1 to 4; n, p, and q indicate the number of structural units, being n = 5 to 1500, p = 0 to 1500, and q = 0 to 1500 respectively; and v indicates an integer 1 to 10.)

Claim 4

The conjugate having cytotoxicity according to Claim 1 and Claim 2, wherein said conjugate is expressed by the following formula (II) (wherein definitions of Ab, S 1 , W, R 1 , Y, n, n, p, q, and v are the same as those given in case of formula (I); S 2 indicates a sulfur atom; B 2 and B 3 are divalent organic groups respectively; and t 2 and t 3 are identical with or different from each other, indicating 0 or 1.)

Claim 5

The conjugate having cytotoxicity according to Claim 1 and Claim 2, wherein said conjugate is expressed by formula (III) (wherein Ab, S 1 , W, R 1 , Y, m, n, p, q, and v are as defined with regard to formula (I); and B 4 indicates a divalent organic group.)

Claim 6

The conjugate having cytotoxicity according to Claim 2, Claim 3, or Claim 4, wherein w is an alkylene group having 1 to 4 carbon atoms in formula (I), formula (II), and formula (III).

Claim 7

A process for the preparation of a conjugate having cytotoxicity expressed by the following formula (II-1) (wherein definitions of Ab, S 1 , W, R 1 , Y, m, n, p, q, and v are the same as those given in case of formula (I); and S 2 , B 2 , and t 2 are as defined with regard to formula (II):) characterized by the reaction of a reactive polymer, which has cytotoxic substance linked thereto and also has an active disulfide group at the terminal of its molecule, expressed by the following formula (V) (wherein definitions of S i , W, R 1 , Y, m, n, p, and q are the same as those given in case of formula (I); and X indicates a group which is capable of forming an active disulfide linkage with the neighboring sulfur atom.) with an immunoglobulin or its fragment expressed by the following formula (IV) having a generated or introduced thiol group (wherein Ab is as defined with regard to formula (I); definitions of S 2 , B 2 , and t 2 are the same as those given with regard to formula (II); and v' is an integer 1 to 10:)

Claim 8

A process for the preparation of a conjugate having cytotoxicity expressed by the following formula (II-1) (wherein definitions of Ab, S 1 , W, R 1 , Y, m, n, p, q, and v are the same as those given in case of formula (I); and S 2 , B 2 , and t 2 are as defined with regard to formula (II):) characterized by the reaction of a reactive polymer, which has cytotoxic substance linked thereto and also has an active disulfide group at the terminal of its molecule, expressed by the following formula (V) (wherein definitions of S i , W, R 1 , Y, m, n, p, and q are the same as those given in case of formula (I); and X indicates a group which is capable of forming an active disulfide linkage with the neighboring sulfur atom.) with an immunoglobulin or its fragment expressed by the following formula (IV) having a generated or introduced thiol group (wherein Ab is as defined with regard to formula (I); definitions of S 2 , B 2 , and t 2 are the same as those given with regard to formula (II); and v' is an integer 1 to 10:)

Claim 9

A process for the preparation of a conjugate having cytotoxicity expressed by the aforementioned formula (II-1) characterized by the reaction of a reactive polymer expressed by the following formula (VII), which has a cytotoxic substance linked thereto and also has a thiol group at the terminal of its molecule, (wherein S 1 , W, R i , Y, m, n, p, and q are as defined with regard to formula (I).) with an immunoglobulin or its fragment expressed by the following formula (VI) having an induced or introduced active disulfide group (wherein Ab is as defined with regard to formula (I); S2, B z , and t 2 are as defined in case of formula (II); v' is as defined in case of formula (IV); and X is as defined with regard to formula (V):)

Claim 10

A process for the preparation of a conjugate having cytotoxicity expressed by the aforementioned formula (II-1) characterized by the reaction of a reactive polymer expressed by the following formula (VII), which has a cytotoxic substance linked thereto and also has a thiol group at the terminal of its molecule, (wherein S 1 , W, R i , Y, m, n, p, and q are as defined with regard to formula (I).) with an immunoglobulin or its fragment expressed by the following formula (VI) having an induced or introduced active disulfide group (wherein Ab is as defined with regard to formula (I); S2, B z , and t 2 are as defined in case of formula (II); v' is as defined in case of formula (IV); and X is as defined with regard to formula (V):)

Claim 11

A process for the preparation of a conjugate having cytotoxicity expressed by the following formula (II-2) (wherein Ab, Si, W, R i , Y, m, n, p, q, and v are as defined in case of formula (I) and B 2 , B 3 , and t 2 are as defined with regard to formula (II);) characterized by binding a reactive polymer, whch has a cytotoxic substance linked thereto and also has a thiol group at the terminal of its molecule, expressed by the abovementioned formula (VII) to an immunoglobulin or its fragment, which has either a generated or introduced thiol group, expressed by the aforementioned formula (IV) by means of a cross linking agent which has 2 functional groups capable of reacting with a thiol group.

Claim 12

A process for the preparation of a conjugate having cytotoxicity expressed by the following formula (II-2) (wherein Ab, Si, W, R i , Y, m, n, p, q, and v are as defined in case of formula (I) and B 2 , B 3 , and t 2 are as defined with regard to formula (II);) characterized by binding a reactive polymer, whch has a cytotoxic substance linked thereto and also has a thiol group at the terminal of its molecule, expressed by the abovementioned formula (VII) to an immunoglobulin or its fragment, which has either a generated or introduced thiol group, expressed by the aforementioned formula (IV) by means of a cross linking agent which has 2 functional groups capable of reacting with a thiol group.

Claim 13

A process for the preparation of a conjugate having cytotoxicity expressed by the aforementioned formula (III) characterized by reacting a reactive polymer, which has a cytotoxic substance linked thereto and also has a thiol group at the terminal of its molecule, expressed by the aforementioned formula (VII) with an immunoglobulin or its fragment, which has a maleimide group introduced thereto, expressed by the following formula (VIII) (wherein definition of Ab is the same as that given in case of formula (I); v' has the meaning given in case of formula (IV); and B 4 is as defined with regard to formula (III):)

Claim 14

A process for the preparation of a conjugate having cytotoxicity expressed by the aforementioned formula (III) characterized by reacting a reactive polymer, which has a cytotoxic substance linked thereto and also has a thiol group at the terminal of its molecule, expressed by the aforementioned formula (VII) with an immunoglobulin or its fragment, which has a maleimide group introduced thereto, expressed by the following formula (VIII) (wherein definition of Ab is the same as that given in case of formula (I); v' has the meaning given in case of formula (IV); and B 4 is as defined with regard to formula (III):)