PYRROLOBENZODIAZEPINE-ANTI-PSMA ANTIBODY CONJUGATES

1 .- 115 . (canceled)

116 . A conjugate of formula L-(D L ) p , where D L is of formula I or II:

wherein:

L is an antibody (Ab) which binds to PSMA, the antibody comprising a VH domain having the amino acid sequence according to any one of SEQ ID NOs. 1, 2, 3, 4, 5, 6, or 7, optionally further comprising a VL domain having the amino acid sequence according to any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14;

when there is a double bond present between C2′ and C3′, R 12 is selected from the group consisting of:

(ia) C 5-10 aryl group, optionally substituted by one or more substituents selected from: halo, nitro, cyano, ether, carboxy, ester, C 1-7 alkyl, C 3-7 heterocyclyl and bis-oxy-C 1-3 alkylene;

(ib) C 1-5 saturated aliphatic alkyl;

(ic) C 3-6 saturated cycloalkyl;

(id)

wherein each of R 21 , R 22 and R 23 are independently selected from H, C 1-3 saturated alkyl, C 2-3 alkenyl, C 2-3 alkynyl and cyclopropyl, where the total number of carbon atoms in the R 12 group is no more than 5;

(ie)

wherein one of R 25a and R 25b is H and the other is selected from: phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl; and

(if)

where R 24 is selected from: H; C 1-3 saturated alkyl; C 2-3 alkenyl; C 2-3 alkynyl; cyclopropyl; phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl;

when there is a single bond present between C2′ and C3′,

R 12 is

where R 26a and R 26b are independently selected from H, F, C 1-4 saturated alkyl, C 2-3 alkenyl, which alkyl and alkenyl groups are optionally substituted by a group selected from C 1-4 alkyl amido and C 1-4 alkyl ester; or, when one of R 26a and R 26b is H, the other is selected from nitrile and a C 1-4 alkyl ester;

R 6 and R 9 are independently 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 1-12 alkyl, C 3-20 heterocyclyl and C 5-20 aryl groups;

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

R″ is a C 3-12 alkylene group, which chain may be interrupted by one or more heteroatoms, e.g. O, S, NR N2 (where R N2 is H or C 1-4 alkyl), and/or aromatic rings, e.g. benzene or pyridine;

Y and Y′ are selected from O, S, or NH;

R 6′ , R 7′ , R 9′ are selected from the same groups as R 6 , R 7 and R 9 respectively;

R L1′ is a linker for connection to the antibody (Ab);

R 11a is selected from OH, OR A , where R A is C 1-4 alkyl, and SO z M, where z is 2 or 3 and M is a monovalent pharmaceutically acceptable cation;

R 20 and R 21 either together form a double bond between the nitrogen and carbon atoms to which they are bound or;

R 20 is selected from H and R C , where R C is a capping group;

R 21 is selected from OH, OR A and SO z M;

when there is a double bond present between C2 and C3, R 2 is selected from the group consisting of:

(ia) C 5-10 aryl group, optionally substituted by one or more substituents selected from the group comprising: halo, nitro, cyano, ether, carboxy, ester, C 1-7 alkyl, C 3-7 heterocyclyl and bis-oxy-C 1-3 alkylene;

(ib) C 1-5 saturated aliphatic alkyl;

(ic) C 3-6 saturated cycloalkyl;

(id)

wherein each of R 11 , R 12 and R 13 are independently selected from H, C 1-3 saturated alkyl, C 2-3 alkenyl, C 2-3 alkynyl and cyclopropyl, where the total number of carbon atoms in the R 2 group is no more than 5;

(ie)

wherein one of R 15a and R 15b is H and the other is selected from: phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl; and

(if)

where R 14 is selected from: H; C 1-3 saturated alkyl; C 2-3 alkenyl; C 2-3 alkynyl; cyclopropyl; phenyl, which phenyl is optionally substituted by a group selected from halo, methyl, methoxy; pyridyl; and thiophenyl;

when there is a single bond present between C2 and C3,

R 2 is

where R 16a and R 16b are independently selected from H, F, C 1-4 saturated alkyl, C 2-3 alkenyl, which alkyl and alkenyl groups are optionally substituted by a group selected from C 1-4 alkyl amido and C 1-4 alkyl ester; or, when one of R 16a and R 16b is H, the other is selected from nitrile and a C 1-4 alkyl ester;

R 22 is of formula Ia, formula IIIb or formula IIIc:

(a)

where A is a C 5-7 aryl group, and either

(i) Q 1 is a single bond, and Q 2 is selected from a single bond and —Z—(CH 2 ) n —, where Z is selected from a single bond, O, S and NH and n is from 1 to 3; or

(ii) Q 1 is —CH═CH—, and Q 2 is a single bond;

(b)

where;

R C1 , R C2 and R C3 are independently selected from H and unsubstituted C 1-2 alkyl;

(c)

where Q is selected from O—R L2′ , S—R L2′ and NR N —R L2′ , and R N is selected from H, methyl and ethyl

X is selected from the group comprising: O—R L2′ , S—R L2′ , CO 2 —R L2′ , CO—R L2′ , NH—C(═O)—R L2′ , NHNH—R L2′ , CONHNH—R L2′ ,

NR N R L2′ , wherein R N is selected from the group comprising H and C 1-4 alkyl;

R L2′ is a linker for connection to the antibody (Ab);

R 10 and R 11 either together form a double bond between the nitrogen and carbon atoms to which they are bound or;

R 10 is H and R 11 is selected from OH, OR A and SO z M;

R 30 and R 31 either together form a double bond between the nitrogen and carbon atoms to which they are bound or;

R 30 is H and R 31 is selected from OH, OR A and SO z M.

117 . The conjugate according to claim 116 , wherein R 7 is a C 1-4 alkyloxy group.

118 . The conjugate according to claim 116 , wherein Y is O and R″ is C 3-7 alkylene.

119 . The conjugate according to claim 116 , wherein R 6 and R 9 are H.

120 . The conjugate according to claim 116 , wherein there is a double bond between C2′ and C3′, and R 12 is:

(a) a C 5-7 aryl group, which may bear one to three substituent groups selected from methoxy, ethoxy, fluoro, chloro, cyano, bis-oxy-methylene, methyl-piperazinyl, morpholino and methyl-thiophenyl; or

(b) methyl, ethyl or propyl; or

(c) cyclopropyl; or

(d) a group of formula:

wherein the total number of carbon atoms in the R 12 group is no more than 4; or

(e) the group:

or

(f) a group of formula:

wherein R 24 is selected from H and methyl.

121 . The conjugate according to claim 116 , wherein there is a single bond between C2′ and C3′, R 12 is

and:

(a) R 26a and R 26b are both H; or

(b) R 26a and R 26b are both methyl; or

(c) one of R 26a and R 26b is H, and the other is selected from C 1-4 saturated alkyl, C 2-3 alkenyl, which alkyl and alkenyl groups are optionally substituted.

122 . The conjugate according to claim 116 , wherein there is a double bond between C2 and C3, and R 2 is:

(a) a C 5-7 aryl group which may bear one to three substituent groups selected from methoxy, ethoxy, fluoro, chloro, cyano, bis-oxy-methylene, methyl-piperazinyl, morpholino and methyl-thiophenyl; or

(b) methyl, ethyl or propyl; or

(c) cyclopropyl; or

(d) a group of formula:

wherein the total number of carbon atoms in the R 2 group is no more than 4; or

(e) the group:

or

(f) a group of formula:

wherein R 14 is selected from H and methyl.

123 . The conjugate according to claim 116 , wherein there is a single bond between C2 and C3, R 2 is

and:

(a) R 16a and R 16b are both H; or

(b) R 16a and R 16b are both methyl; or

(c) one of R 16a and R 16b is H, and the other is selected from C 1-4 saturated alkyl, C 2-3 alkenyl, which alkyl and alkenyl groups are optionally substituted.

124 . The conjugate according to claim 116 , wherein R 20 is R C , wherein R C is a group:

where the asterisk indicates the point of attachment to the N10 position, G 2 is a terminating group, L 3 is a covalent bond or a cleavable linker L 1 , L 2 is a covalent bond or together with OC(═O) forms a self-immolative linker.

125 . The conjugate according to claim 116 , wherein

(a) R 22 is of formula IIIa, and A is phenyl, Q 1 is a single bond, and Q 2 is a single bond; or

(b) R 22 is of formula IIIb, and R C1 , R C2 and R C3 are all H;

and X is NH—R L2′ .

126 . The conjugate according to claim 116 , wherein R 6′ , R 7′ , R 9′ , and Y′ are the same as R 6 , R 7 , R 9 , and Y.

127 . The conjugate according to claim 116 , wherein L-R L1′ or L-R L2′ is a group:

where the asterisk indicates the point of attachment to the PBD, Ab is the antibody, L 1 is a cleavable linker, A is a connecting group connecting L 1 to the antibody, L 2 is a covalent bond or together with —OC(═O)— forms a self-immolative linker.

128 . The conjugate according to claim 127 , wherein the group —X 1 —X 2 — in dipeptide, —NH—X 1 —X 2 —CO—, is selected from:

-Phe-Lys-,

-Val-Ala-,

-Val-Lys-,

-Ala-Lys-,

-Val-Cit-.

129 . The conjugate according to claim 127 , wherein C(═O)O and L 2 together form the group:

where the asterisk indicates the point of attachment to the PBD, the wavy line indicates the point of attachment to the linker L 1 , Y is NH, O, C(═O)NH or C(═O)O, and n is 0 to 3.

130 . A conjugate according to claim 116 of formula ConjA:

131 . The conjugate according to claim 116 , wherein the antibody comprises a VH domain paired with a VL domain, the VH and VL domains having amino acid sequences selected from the group consisting of:

SEQ ID NO. 1 paired with any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14;

SEQ ID NO. 2 paired with any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14;

SEQ ID NO. 3 paired with any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14;

SEQ ID NO. 4 paired with any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14;

SEQ ID NO. 5 paired with any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14;

SEQ ID NO. 6 paired with any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14; and

SEQ ID NO. 7 paired with any one of SEQ ID NOs. 8, 9, 10, 11, 12, 13, or 14.

132 . The conjugate according to claim 131 , wherein the paired VH and VL domains have the sequences of:

SEQ ID NO. 1 paired with SEQ ID NO. 8, SEQ ID NO. 1 paired with SEQ ID NO. 9, SEQ ID NO. 1 paired with SEQ ID NO. 10, SEQ ID NO. 1 paired with SEQ ID NO. 11, SEQ ID NO. 1 paired with SEQ ID NO. 12, SEQ ID NO. 1 paired with SEQ ID NO. 13, SEQ ID NO. 1 paired with SEQ ID NO. 14, SEQ ID NO. 2 paired with SEQ ID NO. 8, SEQ ID NO. 2 paired with SEQ ID NO. 9, SEQ ID NO. 2 paired with SEQ ID NO. 10, SEQ ID NO. 2 paired with SEQ ID NO. 11, SEQ ID NO. 2 paired with SEQ ID NO. 12, SEQ ID NO. 2 paired with SEQ ID NO. 13, SEQ ID NO. 2 paired with SEQ ID NO. 14, SEQ ID NO. 3 paired with SEQ ID NO. 8, SEQ ID NO. 3 paired with SEQ ID NO. 9, SEQ ID NO. 3 paired with SEQ ID NO. 10, SEQ ID NO. 3 paired with SEQ ID NO. 11, SEQ ID NO. 3 paired with SEQ ID NO. 12, SEQ ID NO. 3 paired with SEQ ID NO. 13, SEQ ID NO. 3 paired with SEQ ID NO. 14, SEQ ID NO. 4 paired with SEQ ID NO. 8, SEQ ID NO. 4 paired with SEQ ID NO. 9, SEQ ID NO. 4 paired with SEQ ID NO. 10, SEQ ID NO. 4 paired with SEQ ID NO. 11, SEQ ID NO. 4 paired with SEQ ID NO. 12, SEQ ID NO. 4 paired with SEQ ID NO. 13, SEQ ID NO. 4 paired with SEQ ID NO. 14, SEQ ID NO. 5 paired with SEQ ID NO. 8, SEQ ID NO. 5 paired with SEQ ID NO. 9, SEQ ID NO. 5 paired with SEQ ID NO. 10, SEQ ID NO. 5 paired with SEQ ID NO. 11, SEQ ID NO. 5 paired with SEQ ID NO. 12, SEQ ID NO. 5 paired with SEQ ID NO. 13, SEQ ID NO. 5 paired with SEQ ID NO. 14, SEQ ID NO. 6 paired with SEQ ID NO. 8, SEQ ID NO. 6 paired with SEQ ID NO. 9, SEQ ID NO. 6 paired with SEQ ID NO. 10, SEQ ID NO. 6 paired with SEQ ID NO. 11, SEQ ID NO. 6 paired with SEQ ID NO. 12, SEQ ID NO. 6 paired with SEQ ID NO. 13, SEQ ID NO. 6 paired with SEQ ID NO. 14, SEQ ID NO. 7 paired with SEQ ID NO. 8, SEQ ID NO. 7 paired with SEQ ID NO. 9, SEQ ID NO. 7 paired with SEQ ID NO. 10, SEQ ID NO. 7 paired with SEQ ID NO. 11, SEQ ID NO. 7 paired with SEQ ID NO. 12, SEQ ID NO. 7 paired with SEQ ID NO. 13, or SEQ ID NO. 7 paired with SEQ ID NO. 14.

133 . The conjugate according to claim 116 , wherein the antibody is an intact, humanised, deimmunized, or resurfaced antibody.

134 . The conjugate according to claim 116 , wherein the drug loading (p) of drugs (D) to antibody (Ab) is an integer from 1 to about 8, or wherein p is 1, 2, 3, or 4.

135 . A pharmaceutical composition comprising the conjugate of claim 116 and a pharmaceutically acceptable diluent, carrier, or excipient.

136 . The pharmaceutical composition of claim 135 , further comprising a therapeutically effective amount of a chemotherapeutic agent.

137 . A method of treating cancer comprising administering to a patient the pharmaceutical composition of claim 136 .

138 . The method of claim 137 , wherein the patient is administered a chemotherapeutic agent, in combination with the conjugate.