Fused tricyclic compounds, pharmaceutical compositions containing them and their use in therapy

A compound of formula (I), or a salt or prodrug thereof:

• ##STR9## wherein Q represents a group ##STR10## where W represents a bond, O, S, --CH.sub.2 CH.sub.2 --, --CH.dbd.CH-- or a group NR.sup.6, where R.sup.6 is H or C.sub.1-6 alkyl and one or both of the phenyl rings may be replaced by a heteroaryl moiety;
• X and Y each represent H or X and Y together form a group .dbd.O;
• Z represents O, S or NR.sup.8, where R.sup.8 represents H or C.sub.1-6 alkyl;
• R.sup.1 and R.sup.2 independently represent H;
• C.sub.1-6 alkyl optionally substituted by hydroxy, cyano, COR.sup.a, COOR.sup.a, CONR.sup.a R.sup.b, COC.sub.1-4 alkylNR.sup.a R.sup.b, CONR.sup.a C.sub.1-4 alkylCONR.sup.a R.sup.b or NR.sup.a R.sup.b, (where R.sup.a and R.sup.b each independently represent H, C.sub.1-6 alkyl, phenyl (optionally substituted by one or more of C.sub.1-6 alkyl, C.sub.1-6 alkoxy, halo and trifluoromethyl) or phenyl(C.sub.1-4 alkyl) (optionally substituted in the phenyl ring by one or more of C.sub.1-6 alkyl, C.sub.1-6 alkoxy, halo and trifluoromethyl));
• phenyl(C.sub.1-4 alkyl), (optionally substituted by one or more of C.sub.1-6 alkyl, C.sub.1-6 alkoxy, halo and trifluoromethyl in the phenyl ring);
• C.sub.2-6 alkylene;
• COC.sub.1-6 alkylhalo;
• COR.sup.a ;
• COOR.sup.a ;
• CONHR.sup.a ;
• COC.sub.1-4 alkylNR.sup.a R.sup.b ;
• or CONR.sup.a C.sub.1-4 alkylCONR.sup.a R.sup.b ;
• (where R.sup.a and R.sup.b are as previously defined) or R.sup.1 and R.sup.2 together form a chain (CH.sub.2).sub.p where p is 4 or 5 and where one non-terminal methylene group may optionally be replaced by an oxygen atom or a group NR.sup.x, where R.sup.x is H or C.sub.1-6 alkyl;
• R.sup.3 represents H or C.sub.1-6 alkyl;
• R.sup.4 represents H, C.sub.1-6 alkyl or phenyl (optionally substituted by one or more of C.sub.1-6 alkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, halo, cyano, nitro, trifluoromethyl, trimethylsilyl, SR.sup.c, SOR.sup.c, SO.sub.2 R.sup.c, OR.sup.c, NR.sup.c R.sup.d, NR.sup.c COR.sup.d, NR.sup.c COOR.sup.d, COOR.sup.c or CONR.sup.c R.sup.d, where R.sup.c and R.sup.d each independently represent H, C.sub.1-6 alkyl, phenyl or trifluoromethyl);
• R.sup.5 represents (CH.sub.2).sub.q phenyl, wherein q is 0, 1, 2 or 3 which may optionally be substituted in the phenyl ring by one or more of C.sub.1-6 alkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, halo, cyano, nitro, trifluoromethyl, trimethylsilyl, , SR.sup.c, SOR.sup.c, SO.sub.2 R.sup.c, OR.sup.c, NR.sup.c R.sup.d, NR.sup.c COR.sup.d, NR.sup.c COOR.sup.d, COOR.sup.c or CONR.sup.c R.sup.d, where R.sup.c and R.sup.d are as above defined;
• each R.sup.7 and R.sup.8 independently represents C.sub.1-6 alkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, halo, cyano, nitro, trifluoromethyl, trimethylsilyl, SR.sup.c, SOR.sup.c, SO.sub.2 R.sup.c, OR.sup.c, NR.sup.c R.sup.d, NR.sup.c COR.sup.d, NR.sup.c COOR.sup.d, COOR.sup.c or CONR.sup.c R.sup.d, where R.sup.c and R.sup.d are as above defined;
• and
• m and n independently represent 0, 1, 2, 3 or 4.