T cell recruiting polypeptides capable of binding cd123 and tcr alpha/beta

A nucleic acid encoding a polypeptide that redirects T cells for killing of CD123 expressing cells, comprising one immunoglobulin single variable domain (ISV) that specifically binds T cell receptor (TCR) and one or more ISV that specifically bind CD123, wherein the ISV that specifically binds TCR essentially consists of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which:

• i) CDR1 is chosen from the group consisting of:
• a) SEQ ID NOs:
• 181-191;
• or
• b) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 181-191;
• provided that the ISV comprising the CDR1 with 4, 3, 2 or 1 amino acid(s) difference binds TCR with about the same or a higher affinity compared to the binding by the ISV comprising the CDR1 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• ii) CDR2 is chosen from the group consisting of:
• c) SEQ ID NOs:
• 192-217;
• or
• d) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 192-217;
• provided that the ISV comprising the CDR2 with 4, 3, 2 or 1 amino acid(s) difference binds TCR with about the same or a higher affinity compared to the binding by the ISV comprising the CDR2 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• iii) CDR3 is chosen from the group consisting of:
• e) SEQ ID Nos:
• 218-225;
• or
• f) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 218-225;
• provided that the ISV comprising the CDR3 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR3 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and wherein the one or more ISV that specifically bind CD123 essentially consists of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which:
• i) CDR1 is chosen from the group consisting of:
• a) SEQ ID NOs:
• 11-16;
• or
• b) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 11-16;
• provided that the ISV comprising the CDR1 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR1 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• ii) CDR2 is chosen from the group consisting of:
• c) SEQ ID NOs:
• 17-20;
• or
• d) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 17-20;
• provided that the ISV comprising the CDR2 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR2 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• iii) CDR3 is chosen from the group consisting of:
• e) SEQ ID NOs:
• 21-25;
• or
• f) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 21-25;
• provided that the ISV comprising the CDR3 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR3 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance.

A method for the prevention, treatment and/or amelioration of a CD123 associated disease or condition, comprising the step of administering to a subject in need thereof a pharmaceutically active amount of a polypeptide that redirects T cells for killing of CD123 expressing cells, comprising one immunoglobulin single variable domain (ISV) that specifically binds T cell receptor (TCR) and one or more ISV that specifically bind CD123, wherein the ISV that specifically binds TCR essentially consists of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which:

• i) CDR1 is chosen from the group consisting of:
• a) SEQ ID NOs:
• 181-191;
• or
• b) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 181-191;
• provided that the ISV comprising the CDR1 with 4, 3, 2 or 1 amino acid(s) difference binds TCR with about the same or a higher affinity compared to the binding by the ISV comprising the CDR1 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• ii) CDR2 is chosen from the group consisting of:
• c) SEQ ID NOs:
• 192-217;
• or
• d) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 192-217;
• provided that the ISV comprising the CDR2 with 4, 3, 2 or 1 amino acid(s) difference binds TCR with about the same or a higher affinity compared to the binding by the ISV comprising the CDR2 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• iii) CDR3 is chosen from the group consisting of:
• e) SEQ ID Nos:
• 218-225;
• or
• f) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 218-225;
• provided that the ISV comprising the CDR3 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR3 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and wherein the one or more ISV that specifically bind CD123 essentially consists of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which:
• i) CDR1 is chosen from the group consisting of:
• a) SEQ ID NOs:
• 11-16;
• or
• b) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 11-16;
• provided that the ISV comprising the CDR1 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR1 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• ii) CDR2 is chosen from the group consisting of:
• c) SEQ ID NOs:
• 17-20;
• or
• d) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 17-20;
• provided that the ISV comprising the CDR2 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR2 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance;
• and
• iii) CDR3 is chosen from the group consisting of:
• e) SEQ ID NOs:
• 21-25;
• or
• f) amino acid sequences that have 4, 3, 2 or 1 amino acid(s) difference with the amino acid sequence of one of SEQ ID NOs:
• 21-25;
• provided that the ISV comprising the CDR3 with 4, 3, 2 or 1 amino acid(s) difference binds CD123 with about the same or a higher affinity compared to the binding by the ISV comprising the CDR3 without the 4, 3, 2 or 1 amino acid(s) difference, said affinity as measured by surface plasmon resonance.