Multifunctional molecules that bind to calreticulin and uses thereof

1. A multifunctional molecule, comprising:

(i) a first antigen binding domain that binds to a first calreticulin protein and

(ii) one, two, or all of:

(a) an immune cell engager chosen from a T cell engager, an NK cell engager, a B cell engager, a dendritic cell engager, or a macrophage cell engager;

(b) a cytokine molecule or a modulator of a cytokine molecule; and

(c) a stromal modifying moiety, wherein:

the first antigen binding domain comprises a heavy chain variable region (VH) comprising a heavy chain complementarity determining region 1 (VHCDR1) amino acid sequence of SEQ ID NO: 107, a VHCDR2 amino acid sequence of SEQ ID NO: 243, and a VHCDR3 amino acid sequence of SEQ ID NO: 109, and a light chain variable region (VL) comprising a light chain complementarity determining region 1 (VLCDR1) amino acid sequence of SEQ ID NO: 113, a VLCDR2 amino acid sequence of SEQ ID NO: 114, and a VLCDR3 amino acid sequence of SEQ ID NO: 115.

2. The multifunctional molecule of claim 1 , wherein the multifunctional molecule preferentially binds to a myeloproliferative neoplasm cell over a non-tumor cell, optionally wherein the binding between the multifunctional molecule and the myeloproliferative neoplasm cell is more than 10, 20, 30, 40, 50-fold greater than the binding between the multifunctional molecule and a non-tumor cell.

3. The multifunctional molecule of claim 2 , wherein the myeloproliferative neoplasm cell is chosen from a myelofibrosis cell, an essential thrombocythemia cell, a polycythemia vera cell, or a chronic myeloid cancer cell, optionally wherein:

the myeloproliferative neoplasm cell does not comprise a JAK2 V617F mutation, or the myeloproliferative neoplasm cell does not comprise a MPL mutation.

4. The multifunctional molecule of claim 1 , wherein the first antigen binding domain comprises:

(i) a VH comprising a heavy chain framework region 1 (VHFWR1) amino acid sequence of SEQ ID NO: 80, a VHFWR2 amino acid sequence of SEQ ID NO: 81, a VHFWR3 amino acid sequence of SEQ ID NO: 82, and/or a VHFWR4 amino acid sequence of SEQ ID NO: 83;

(ii) a VH comprising a heavy chain framework region 1 (VHFWR1) amino acid sequence of SEQ ID NO: 84, a VHFWR2 amino acid sequence of SEQ ID NO: 85, a VHFWR3 amino acid sequence of SEQ ID NO: 86, and/or a VHFWR4 amino acid sequence of SEQ ID NO: 83; and/or

(iii) a VL comprising a light chain framework region 1 (VLFWR1) amino acid sequence of SEQ ID NO: 87, a VLFWR2 amino acid sequence of SEQ ID NO: 88, a VLFWR3 amino acid sequence of SEQ ID NO: 89, and/or a VLFWR4 amino acid sequence of SEQ ID NO: 90.

5. The multifunctional molecule of claim 1 , wherein the first antigen binding domain comprises:

(i) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 233, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(ii) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 234, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(iii) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 235, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(iv) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 236, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(v) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 237, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238; or

(vi) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 244, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 245.

6. The multifunctional molecule of claim 5 , wherein the first antigen binding domain comprises:

(i) VH comprising the amino acid sequence of SEQ ID NO: 233, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(ii) a VH comprising the amino acid sequence of SEQ ID NO: 234, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(iii) a VH comprising the amino acid sequence of SEQ ID NO: 235, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(iv) a VH comprising the amino acid sequence of SEQ ID NO: 236, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(v) a VH comprising the amino acid sequence of SEQ ID NO: 237, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238; or

(vi) a VH comprising the amino acid sequence of SEQ ID NO: 244, and/or a VL comprising the amino acid sequence of SEQ ID NO: 245.

7. The multifunctional molecule of claim 1 , wherein the multifunctional molecule further comprises a second antigen binding domain that binds to a second calreticulin protein, wherein the second antigen binding domain comprises:

(i) a heavy chain variable region (VH) comprising a heavy chain complementarity determining region 1 (VHCDR1) amino acid sequence of SEQ ID NO: 107, a VHCDR2 amino acid sequence of SEQ ID NO: 243, and a VHCDR3 amino acid sequence of SEQ ID NO: 109, and a light chain variable region (VL) comprising a light chain complementarity determining region 1 (VLCDR1) amino acid sequence of SEQ ID NO: 113, a VLCDR2 amino acid sequence of SEQ ID NO: 114, and a VLCDR3 amino acid sequence of SEQ ID NO: 115;

(ii) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 107, a VHCDR2 amino acid sequence of SEQ ID NO: 108, and a VHCDR3 amino acid sequence of SEQ ID NO: 109; and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 113, a VLCDR2 amino acid sequence of SEQ ID NO: 114, and a VLCDR3 amino acid sequence of SEQ ID NO: 115; or

(iii) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 110, a VHCDR2 amino acid sequence of SEQ ID NO: 111, and a VHCDR3 amino acid sequence of SEQ ID NO: 112 or 116, and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 113, a VLCDR2 amino acid sequence of SEQ ID NO: 114, and a VLCDR3 amino acid sequence of SEQ ID NO: 115.

8. The multifunctional molecule of claim 1 , wherein the multifunctional molecule further comprises a second antigen binding domain that binds to a second calreticulin protein wherein the second antigen binding domain comprises:

(i) a heavy chain variable region (VH) comprising a heavy chain framework region 1 (VHFWRI) amino acid sequence of SEQ ID NO: 80, a VHFWR2 amino acid sequence of SEQ ID NO: 81, a VHFWR3 amino acid sequence of SEQ ID NO: 82, or a VHFWR4 amino acid sequence of SEQ ID NO: 83,

(ii) a heavy chain variable region (VH) comprising a heavy chain framework region 1 (VHFWRI) amino acid sequence of SEQ ID NO: 84, a VHFWR2 amino acid sequence of SEQ ID NO: 85, a VHFWR3 amino acid sequence of SEQ ID NO: 86, or a VHFWR4 amino acid sequence of SEQ ID NO: 83, or

(iii) a light chain variable region (VL) comprising a light chain framework region 1 (VLFWR1) amino acid sequence of SEQ ID NO: 87, a VLFWR2 amino acid sequence of SEQ ID NO: 88, a VLFWR3 amino acid sequence of SEQ ID NO: 89, or a VLFWR4 amino acid sequence of SEQ ID NO: 90.

9. The multifunctional molecule of claim 1 , wherein the multifunctional molecule further comprises a second antigen binding domain that binds to a second calreticulin protein wherein the second antigen binding domain comprises:

(i) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 233, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(ii) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 234, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(iii) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 235, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(iv) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 236, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238;

(v) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 237, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 238; or

(vi) a VH comprising an amino acid sequence having at least 80% sequence identity to SEQ ID NO: 244, and/or a VL comprising an amino acid sequence having at least 90% sequence identity to SEQ ID NO: 245.

10. The multifunctional molecule of claim 1 , wherein the multifunctional molecule further comprises a second antigen binding domain that binds to a second calreticulin protein wherein the second antigen binding domain comprises:

(i) VH comprising the amino acid sequence of SEQ ID NO: 233, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(ii) a VH comprising the amino acid sequence of SEQ ID NO: 234, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(iii) a VH comprising the amino acid sequence of SEQ ID NO: 235, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(iv) a VH comprising the amino acid sequence of SEQ ID NO: 236, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238;

(v) a VH comprising the amino acid sequence of SEQ ID NO: 237, and/or a VL comprising the amino acid sequence of SEQ ID NO: 238; or

(vi) a VH comprising the amino acid sequence of SEQ ID NO: 244, and/or a VL comprising the amino acid sequence of SEQ ID NO: 245.

11. The multifunctional molecule of claim 1 , wherein the multifunctional molecule comprises the cytokine molecule, wherein the cytokine molecule is chosen from interleukin-2 (IL-2) or a functional variant thereof, interleukin-7 (IL-7) or a functional variant thereof, interleukin-12 (IL-12) or a functional variant thereof, interleukin-15 (IL-15) or a functional variant thereof, interleukin-18 (IL-18) or a functional variant thereof, interleukin-21 (IL-21) or a functional variant thereof, interferon gamma or a functional variant thereof, and any combination thereof.

12. The multifunctional molecule of claim 11 , wherein the interleukin-2 (IL-2) or a functional variant thereof comprises an amino acid sequence have at least 95% sequence identity of SEQ ID NO: 20, SEQ ID NO: 227 or SEQ ID NO: 228.

13. The multifunctional molecule of claim 1 , wherein the multifunctional molecule comprises the following configuration:

A,B-[dimerization module]-C,-D,

wherein:

(1) the dimerization module comprises an immunoglobulin constant domain, or a constant domain of an immunoglobulin variable region; and

(2) A, B, C, and D are independently absent; (i) an antigen binding domain that binds to a calreticulin protein; (ii) an immune cell engager chosen from a T cell engager, an NK cell engager, a B cell engager, a dendritic cell engager, or a macrophage cell engager;

(iii) a cytokine molecule or a modulator of a cytokine molecule; or (iv) a stromal modifying moiety, provided that:

at least one, two, or three of A, B, C, and D comprises an antigen binding domain that binds to a calreticulin protein, and

any of the remaining A, B, C, and D is absent or comprises one of an immune cell engager, a cytokine molecule or a modulator of a cytokine molecule, or a stromal modifying moiety.

14. The multifunctional molecule of claim 1 , wherein the multifunctional molecule further comprises a dimerization module comprising a first immunoglobulin chain constant region and a second immunoglobulin chain constant region.

15. The multifunctional molecule of claim 14 , wherein the first antigen binding domain is linked to the first immunoglobulin chain constant region.

16. The multifunctional molecule of claim 14 , wherein the cytokine molecule or the modulator of a cytokine molecule is linked to the first immunoglobulin chain constant region, the second immunoglobulin chain constant region, or the first immunoglobulin chain constant region and the second immunoglobulin chain constant region.

17. The multifunctional molecule of claim 1 , wherein the multifunctional molecule further comprises one or more of:

(i) a linker between the first antigen binding domain and the immune cell engager,

(ii) a linker between the first antigen binding domain and the cytokine molecule or the modulator of a cytokine molecule,

(iii) a linker between the first antigen binding domain and the stromal modifying moiety,

(iv) a linker between the immune cell engager and the cytokine molecule or the modulator of a cytokine molecule,

(v) a linker between the immune cell engager and the stromal modifying moiety, or

(vi) a linker between the cytokine molecule or the modulator of a cytokine molecule and the stromal modifying moiety,

optionally, wherein the linker is chosen from: a cleavable linker, a non-cleavable linker, a peptide linker, a flexible linker, a rigid linker, a helical linker, and a non-helical linker.

18. The multifunctional molecule of claim 14 , wherein the multifunctional molecule further comprises one or more of:

(i) a linker between the first antigen binding domain and the first immunoglobulin chain constant region,

(ii) a linker between the immune cell engager and the first immunoglobulin chain constant region, the second immunoglobulin chain constant region or the first immunoglobulin chain constant region and the second immunoglobulin chain constant region, or

(iii) a linker between the cytokine molecule or the modulator of a cytokine molecule and the first immunoglobulin chain constant region, the second immunoglobulin chain constant region or the first immunoglobulin chain constant region and the second immunoglobulin chain constant region, or a linker between or the stromal modifying moiety and the first immunoglobulin chain constant region, the second immunoglobulin chain constant region or the first immunoglobulin chain constant region and the second immunoglobulin chain constant region,

optionally, wherein the linker is chosen from: a cleavable linker, a non-cleavable linker, a peptide linker, a flexible linker, a rigid linker, a helical linker, and a non-helical linker.

19. The multifunctional molecule of claim 7 , wherein the multifunctional molecule further comprises one or more of:

(i) a linker between the second antigen binding domain and the immune cell engager,

(ii) a linker between the second antigen binding domain and the cytokine molecule or the modulator of a cytokine molecule, or

(iii) a linker between the second antigen binding domain and the stromal modifying moiety,

optionally, wherein the linker is chosen from: a cleavable linker, a non-cleavable linker, a peptide linker, a flexible linker, a rigid linker, a helical linker, and a non-helical linker.

20. The multifunctional molecule of claim 7 , wherein the multifunctional molecule further comprises a dimerization module comprising a first immunoglobulin chain constant region and a second immunoglobulin chain constant region, and wherein the multifunctional molecule further comprises one or more of a linker between the second antigen binding domain and the first immunoglobulin chain constant region, the second immunoglobulin chain constant region, or the first immunoglobulin chain constant region and the second immunoglobulin chain constant region,

optionally, wherein the linker is chosen from: a cleavable linker, a non-cleavable linker, a peptide linker, a flexible linker, a rigid linker, a helical linker, and a non-helical linker.