Alkyl 4- [4- (5-oxo-2,3,5, 11a-tetrahydo-5H-pyrrolo [2, 1-c] [1,4] benzodiazepine-8-yloxy)-butyrylamino]-1H-pyrrole-2-carboxylate derivatives and related compounds for the treatment of a proliferative disease

1. A compound of formula I:

or a salt thereof, wherein:

the dotted line indicates the optional presence of a double bond between C2 and C3;

R 2 is selected from —H, —OH, ═O, ═CH 2 , —CN, —R, OR, halo, ═CH—R, O—SO 2 —R, CO 2 R and COR;

R 7 is selected from H, R, OH, OR, SH, SR, NH 2 , NHR, NRR′, nitro, Me 3 Sn and halo;

where R and R′ are independently selected from optionally substituted C 1-7 alkyl, C 3-20 heterocyclyl and C 5-20 aryl groups;

R 10 and R 11 either are selected from H and YR Y , where Y is selected from O, S and NH and R Y is H or C 1-7 alkyl or H and SO x M where x is 2 or 3, and M is a monovalent pharmaceutically acceptable cation or are absent and a double bond is formed between the atoms bearing R 10 and R 11 ;

each X is an N-methyl substituted pyrrole;

n is from 1 to 6;

R E is C 1-4 alkyl.

2. A compound according to claim 1 , wherein n is from 2 to 6.

3. A compound according to claim 1 , wherein R 7 is independently selected from H and OR, where R is selected from optionally substituted C 1-7 alkyl, C 3-10 heterocyclyl and C 5-10 aryl groups.

4. A compound according to claim 1 , wherein R 10 and R 11 either form a double bond together or R 11 is selected from H and OR Y , where R Y is H or Me.

5. A compound according to claim 1 , wherein R E is C 1-2 alkyl.

6. A pharmaceutical composition comprising a compound according to claim 1 and a pharmaceutically acceptable carrier or diluent.

7. A method of treatment of a patient suffering from a proliferative disease, comprising administering to said patient a therapeutically acceptable amount of a compound according to claim 1 or a composition according to claim 6 .