HUMANIZED ANTI-AXL ANTIBODIES AND THEIR CONJUGATES

1 .- 126 . (canceled)

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

wherein:

L is an isolated humanized antibody (Ab) that binds to AXL, wherein the isolated humanized antibody comprises a heavy chain variable region having the amino acid sequence of SEQ ID NO: 2 or SEQ ID NO: 3;

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 the group comprising: halo, nitro, cyano, ether, carboxy, ester, C 1-7 alkyl, CO 3-7 heterocyclyl and bis-oxy-C 1-3 alkylene;

(ib) C 1-5 saturated aliphatic alkyl;

(ic) C 3-6 saturated cycloalkyl;

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;

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

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;

[Formula I]

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;

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;

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

where R 14 is selected from: H; C1-3 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;

[Formula II]

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

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;

where;

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

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.

128 . The conjugate of claim 127 , wherein R 7 is a C 1-4 alkyloxy group.

129 . The conjugate of claim 127 , wherein Y is O and R″ is C 3-7 alkylene.

130 . The conjugate of claim 127 , wherein R 6 and R 9 are H.

131 . The conjugate of claim 127 , 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.

132 . The conjugate of claim 127 , 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.

[Formula I]

133 . The conjugate of claim 127 , 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.

134 . The conjugate of claim 127 , 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.

135 . The conjugate of claim 127 , 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.

[Formula II]

136 . The conjugate of claim 127 , wherein:

(a) R 22 is of formula IIIa, A is phenyl, Q 1 is a single bond, 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′ .

137 . The conjugate of claim 127 , wherein R 6′ , R 7′ , R 9′ , and Y′ are the same as R 6 , R 7 , R 9 , and Y.

138 . The conjugate of claim 127 , 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.

139 . The conjugate of claim 138 , wherein L 1 comprises a dipeptide and 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-.

140 . The conjugate of claim 139 , 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.

141 . A conjugate of claim 127 of formula

142 . The conjugate of claim 127 , wherein the isolated humanized antibody further comprises a light chain variable region having the amino acid sequence of SEQ ID NO: 4, 5, 6, 7, or 8; and, optionally,

comprises a constant region derived from one or more human antibodies.

143 . The conjugate of claim 127 , wherein the isolated humanized antibody comprises:

(i) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 2 and a light chain variable region having the amino acid sequence of SEQ ID NO: 4;

(ii) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 2 and a light chain variable region having the amino acid sequence of SEQ ID NO: 5;

(iii) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 2 and a light chain variable region having the amino acid sequence of SEQ ID NO: 6;

(iv) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 2 and a light chain variable region having the amino acid sequence of SEQ ID NO: 7;

(v) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 2 and a light chain variable region having the amino acid sequence of SEQ ID NO: 8;

(vi) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 3 and a light chain variable region having the amino acid sequence of SEQ ID NO: 4;

(vii) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 3 and a light chain variable region having the amino acid sequence of SEQ ID NO: 5;

(viii) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 3 and a light chain variable region having the amino acid sequence of SEQ ID NO: 6;

(viv) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 3 and a light chain variable region having the amino acid sequence of SEQ ID NO: 7; or

(x) a heavy chain variable region having the amino acid sequence of SEQ ID NO: 3 and a light chain variable region having the amino acid sequence of SEQ ID NO: 8.

144 . The conjugate of claim 127 , wherein said antibody competitively inhibits the binding to human AXL of an antibody comprising a heavy chain variable region having the amino acid sequence of SEQ ID NO: 1 and a light chain variable region having the amino acid sequence of SEQ ID NO: 4.

145 . The conjugate of claim 127 , wherein said antibody or antibody fragment has a constant region of either isotype IgG1, IgG2, IgG3 or IgG4, or a mutated IgG constant region, and optionally a light chain constant region of isotype kappa or lambda.

146 . The conjugate of claim 145 , wherein p is 1, 2, 3, or 4.

147 . The conjugate of claim 145 , comprising a mixture of the antibody-drug conjugate compounds, wherein the average drug loading per antibody in the mixture of antibody-drug conjugate compounds is about 2 to about 5.

148 . The conjugate of claim 127 , for use in therapy.

149 . The conjugate of claim 127 , for use in the treatment of a proliferative disease in a subject.

150 . The conjugate of claim 149 , wherein the disease is cancer.

151 . A pharmaceutical composition comprising the conjugate of claim 127 and a pharmaceutically acceptable diluent, carrier or excipient.

152 . The pharmaceutical composition of claim 151 , further comprising a therapeutically effective amount of a chemotherapeutic agent.

153 . A method of selecting an individual for treatment with the conjugate of claim 127 , which method comprises assessing the level of AXL; wherein individuals having raised levels of AXL are selected for treatment.

154 . A method of timing the application of treatment of an individual with the conjugate of claim 127 , which method comprises assessing the level of AXL; wherein the treatment is applied if the individual has raised levels of AXL.

155 . The method according to claim 153 , wherein the individual has cancer and treatment reduces tumour volume.