A conjugate of an antibody or a functional fragment thereof together with one or more chemical compound(s) as defined in following formula: in which n is 1 to 8 and AK is an anti-CD123 antibody or a functional fragment thereof where the antibody or the functional fragment thereof is attached via a cysteine residue and said antibody or functional fragment thereof comprises a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 122, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 123, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 124, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 126, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 127, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 128, or a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 202, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 203, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 204, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 206, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 207, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 208, or a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 132, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 133, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 134, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 136, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 137, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 138. n is 1 to 8 and AK is an anti-CD123 antibody or a functional fragment thereof where the antibody or the functional fragment thereof is attached via a cysteine residue and said antibody or functional fragment thereof comprises a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 122, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 123, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 124, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 126, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 127, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 128, or a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 202, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 203, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 204, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 206, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 207, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 208, or a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 132, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 133, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 134, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 136, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 137, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 138. is an anti-CD123 antibody or a functional fragment thereof where the antibody or the functional fragment thereof is attached via a cysteine residue and said antibody or functional fragment thereof comprises a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 122, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 123, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 124, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 126, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 127, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 128, or a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 202, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 203, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 204, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 206, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 207, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 208, or a variable heavy chain comprising the variable CDR1 sequence of the heavy chain, as shown in SEQ ID NO: 132, the variable CDR2 sequence of the heavy chain, as shown in SEQ ID NO: 133, and the variable CDR3 sequence of the heavy chain, as shown in SEQ ID NO: 134, and a variable light chain comprising the variable CDR1 sequence of the light chain, as shown in SEQ ID NO: 136, the variable CDR2 sequence of the light chain, as shown in SEQ ID NO: 137, and the variable CDR3 sequence of the light chain, as shown in SEQ ID NO: 138.