The invention relates to pyrridinobenzodiazepines (PDDs) comprising three fused 6-7- 6–membered rings and to benzopyrridodiazecines (BPDs) comprising three fused 6-8- 6–membered rings and, in particular, to PDD or BPD dimers linked together or PDD and BPD monomers linked to aromatic groups, and pharmaceutically acceptable salts thereof, which are useful as medicaments, such as anti-proliferative agents. PDDs and BPDs may be represented by formula (I): and salts or solvates thereof, wherein R2, R4-R6 and R8 are independently selected substituent groups and either: (i) R9 and R10 together form a double bond (ii) R9 is H and R10 is OH or (iii) R9 is H and R10 is ORA and RA is C1-6 alkyl wherein each of m, n, u and w may be 0 or 1 where (a) the compound is a dimer with each monomer being the same or different and being of formula (I) where one of R1, R2, R3 and R7 of the first monomer and one of R1, R2, R3 and R7 of the second monomer form together a bridge having the formula –X-L-X- linking the monomers and m + n + u + w = 1 or (b) a dimer and one of R1, R2 and R3 of the first monomer and one of R1, R2 and R3 of the second monomer form together a bridge having the formula –X-L-X- linking the monomers and m = n = u = w = o or (c) one of R1, R2, R3 and R7 has the formula: –X- L-X-D or -(CH2)f-O-R14 and m + n + u + w = o or 1 or (d) R7 has the formula: –X-L-X- D or -(CH2)g-O -15 and m + n + u + w = 1 and X-L-X- is a linker group and D has the formula (II) or (III):
