Human antibodies to serum resistance-associated protein from trypanosoma brucei rhodesiense

Patent metadata

Field	Value
Publication number	US-9751936-B2
Application number	US-201414768182-A
Country	US
Kind code	B2
Filing date	Feb 26, 2014
Priority date	Mar 8, 2013
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

The present invention provides antibodies that bind to serum resistance-associated (SRA) protein of Trypanosoma brucei rhodesiense , and methods of use. According to certain embodiments of the invention, the antibodies are fully human antibodies that bind to SRA. The antibodies of the invention are useful for inhibiting or neutralizing SRA activity, thus providing a means of treating human African trypanosomiasis (sleeping sickness), and symptoms associated with the disease. The antibodies of the invention may also be useful for diagnosis of sleeping sickness.

First claim

What is claimed is:

1. An isolated antibody or antigen-binding fragment thereof that binds specifically to SRA at pH7.4 and remains bound at pH4;
the antibody or antigen binding fragment thereof comprising a HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, and 274/282.

2. An isolated antibody or antigen-binding fragment thereof that binds specifically to SRA at 25° C. and acidic pH with a dissociative half-life (t½) of less than about 4 minutes, wherein the antibody binds to SRA at 25° C. at neutral pH with a t½ of greater than about 20 minutes, as determined by surface plasmon resonance;
the antibody or antigen binding fragment thereof comprising a HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, and 274/282.

3. An isolated antibody or antigen-binding fragment thereof that binds specifically to SRA at 25° C. and acidic pH with a dissociative half-life (t½) of less than about 100 minutes, wherein the antibody binds to SRA at 25° C. at neutral pH with a t½ of greater than about 150 minutes, as determined by surface plasmon resonance;
the antibody or antigen binding fragment thereof comprising a HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, and 274/282.

4. An isolated antibody or antigen-binding fragment thereof that binds specifically to SRA at acidic pH and at neutral pH, wherein the dissociation rate constant (kd) for the antibody binding to SRA at 25° C. is less than about 1.7×10 −2 , as determined by surface plasmon resonance;
the antibody or antigen binding fragment thereof comprising a HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 66/74, 82/90, 98/106, 114/122, 130/138, 146/154, 162/170, 178/186, 194/202, 210/218, 226/234, 242/250, 258/266, and 274/282.

5. An isolated antibody or antigen-binding fragment thereof that binds specifically to SRA, wherein the antibody or antigen-binding fragment thereof binds to an epitope on SRA (SEQ ID NO: 290) comprising an amino acid selected from the group consisting of S-174, I-175, V-176, K-177, K-178, P-179, K-180, G-181, A-182, P-183, D-184, K-185, T-186, A-187, A-188, D-189, E-190, L-191, V-192, T-193 and A-194;
wherein the antibody comprises:
three heavy chain complementarity determining regions (CDRs) (HCDR1, HCDR2 and HCDR3) contained within any one of the heavy chain variable region (HCVR) sequences selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 114, 130, 146, 162, 178, 194, 210, 226, 242, 258, and 274; and three light chain CDRs (LCDR1, LCDR2 and LCDR3) contained within any one of the light chain variable region (LCVR) sequences selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266 and 282.

6. An isolated antibody or antigen-binding fragment thereof that competes for specific binding to SRA with an antibody or antigen-binding fragment comprising three CDRs of a HCVR, wherein the HCVR has an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 18, 34, 50, 66, 82, 98, 114, 130, 146, 162, 178, 194, 210, 226, 242, 258, and 274; and three CDRs of a LCVR, wherein the LCVR has an amino acid sequence selected from the group consisting of SEQ ID NOs: 10, 26, 42, 58, 74, 90, 106, 122, 138, 154, 170, 186, 202, 218, 234, 250, 266, and 282.

7. The isolated antibody or antigen-binding fragment thereof of claim 6 , comprising:
(a) a HCDR1 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 20, 36, 52, 68, 84, 100, 116, 132, 148, 164, 180, 196, 212, 228, 244, 260, and 276;
(b) a HCDR2 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 22, 38, 54, 70, 86, 102, 118, 134, 150, 166, 182, 198, 214, 230, 246, 262, and 278;
(c) a HCDR3 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 8, 24, 40, 56, 72, 88, 104, 120, 136, 152, 168, 184, 200, 216, 232, 248, 264, and 280;
(d) a LCDR1 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 12, 28, 44, 60, 76, 92, 108, 124, 140, 156, 172, 188, 204, 220, 236, 252, 268, and 284;
(e) a LCDR2 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 14, 30, 46, 62, 78, 94, 110, 126, 142, 158, 174, 190, 206, 222, 238, 254, 270, and 286; and
(f) a LCDR3 domain having an amino acid sequence selected from the group consisting of SEQ ID NOs: 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 256, 272, and 288.

8. The isolated antibody or antigen-binding fragment of claim 7 , wherein the antibody:
blocks SRA binding to apoL1, wherein the antibody comprises a HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 66/74, 98/106, 130/138, 146/154, 162/170, 210/218, 226/234, 242/250, 258/266, and 274/282; or
does not block SRA binding to apoL1, wherein the antibody comprises a HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 2/10, 18/26, 34/42, 50/58, 82/90, 114/122, 178/186, and 194/202.

9. An isolated antibody or antigen-binding fragment thereof that binds to SRA and blocks SRA binding to apoL1 at pH ranging from about 7.4 to about 4.5, the antibody or antigen-binding fragment thereof comprising three CDRs of a HCVR, wherein the HCVR has an amino acid sequence selected from the group consisting of SEQ ID NOs: 66, 98, 130, 146, 162, 210, 226, 242, 258, and 274; and three CDRs of a LCVR, wherein the LCVR has an amino acid sequence selected from the group consisting of SEQ ID NOs: 74, 106, 138, 154, 170, 218, 234, 250, 266, and 282.

10. An isolated antibody or antigen-binding fragment thereof that binds to SRA and blocks SRA binding to apoL1 at pH4.5, the antibody or antigen-binding fragment thereof comprising three CDRs of a HCVR, wherein the HCVR has an amino acid sequence selected from the group consisting of SEQ ID NOs: 66, 98, 130, 146, 162, 210, 226, 242, 258, and 274; and three CDRs of a LCVR, wherein the LCVR has an amino acid sequence selected from the group consisting of SEQ ID NOs: 74, 106, 138, 154, 170, 218, 234, 250, 266, and 282.

11. A pharmaceutical composition comprising an isolated human antibody or antigen-binding fragment thereof that binds to SRA according to claim 10 and a pharmaceutically acceptable carrier or diluent
wherein the antibody or antigen-binding fragment thereof comprises the HCVR/LCVR amino acid sequence pair selected from the group consisting of SEQ ID NOs: 66/74, 98/106, 130/138, 146/154, 162/170, 210/218, 226/234, 242/250, 258/266, and 274/282.

12. A method for treating a patient suffering from sleeping sickness, or for treating at least one symptom or complication associated with sleeping sickness, or for treating a patient at risk for developing sleeping sickness, the method comprising administering to the patient a pharmaceutical composition comprising an effective amount of an antibody or an antigen-binding fragment thereof that binds to SRA according to claim 11 , such that the sleeping sickness—associated condition or disease is either prevented, or lessened in severity and/or duration, or at least one symptom or comp

Assignees

• Regeneron Pharma

Inventors

• Papadopoulos Nicholas J

Classifications

• C07K2317/21

  from primates, e.g. man · CPC title

• C07K2317/73

  Inducing cell death, e.g. apoptosis, necrosis or inhibition of cell proliferation · CPC title

• C07K2317/76

  Antagonist effect on antigen, e.g. neutralization or inhibition of binding · CPC title

• C07K2317/94

  Stability, e.g. half-life, pH, temperature or enzyme-resistance · CPC title

• C07K16/20 Primary

  from protozoa · CPC title