TGFβ1-binding immunoglobulins and use thereof
Disclosed herein are immunoglobulins, such as antibodies, and antigen binding portions thereof, that specifically bind complexes of GARP-TGFβ1, LTBP1-TGFβ1, LTBP3-TGFβ1, and/or LRRC33-TGFβ1. The application also provides methods of use of these immunoglobulins for, for example, inhibiting TGFβ1 activity, and treating subjects suffering from TGFβ1-related disorders, such as cancer and fibrosis.
1. A method for identifying a transforming growth factor beta 1 (TGFβ1)-specific inhibitor, wherein the TGFβ1-specific inhibitor is an antibody or antigen-binding fragment thereof, comprising:
(i) providing an antibody or antigen-binding fragment thereof and performing a binding assay to detect isoform-specific binding to TGFβ1 and not to TGFβ2 or TGFβ3;
(ii) contacting the antibody or antigen-binding fragment thereof with a TGFβ1 protein or a complex comprising TGFβ1 and determining relative changes in TGFβ1 activation in the presence and absence of the antibody or antigen-binding fragment thereof;
(iii) carrying out an in vivo efficacy study to assess therapeutic effectiveness of the antibody or antigen-binding fragment thereof in an animal model, wherein the inhibitor antibody or antigen-binding fragment thereof shows efficacy when administered at a dose of about 0.1 pg/kg to about 30 mg/kg:
(iv) carrying out an in vivo safety study to assess cardiovascular toxicity of the antibody or antigen-binding fragment thereof in an animal model, wherein the antibody or antigen-binding fragment thereof shows minimal or no cardiovascular toxicity when dosed at 100 mg/kg/week for four weeks, and wherein the cardiovascular toxicity comprises valvulopathy and/or hemorrhage in the heart;
thereby identifying the TGFβ1-specific inhibitor.
2. The method of claim 1 , wherein the animal model of step (iv) is a rat model.
3. The method of claim 1 , wherein the TGFβ1-specific inhibitor shows reduced toxicity as compared to a pan TGFβ inhibitor in the in vivo safety study.
4. The method of claim 1 , wherein the TGFβ1-specific inhibitor achieves reduced expression of at least one gene selected from the group consisting of: plasminogen activator inhibitor-1 (PAI-1), connective tissue growth factor (CTGF), monocyte chemotactic protein 1 (MCP-1), TGFB1, alpha-smooth muscle actin (α-SMA), Fibronectin-1, collagen type I alpha 1 (Col1a1) and collagen type III alpha 1 (Col3a1).
5. The method of claim 1 , wherein the animal model of step (iii) comprises a fibrotic model.
6. The method of claim 1 , wherein the animal model of step (ii) (iii) comprises a tumor model.
7. The method of claim 6 , wherein the in vivo efficacy study in the tumor model further comprises administration of a checkpoint inhibitor.
8. The method of claim 7 , wherein the checkpoint inhibitor is a PD-1 antagonist or a PD-L1 antagonist.
9. The method of claim 6 , wherein the tumor model is a desmoplastic tumor model.
10. The method of claim 1 , wherein the TGFβ1-specific inhibitor specifically binds a pro/latent complex of TGFβ1 but does not bind free mature TGFβ1 which is not associated with the pro/latent complex of TGFβ1.
11. The method of claim 10 , wherein the pro/latent complex comprises glycoprotein-A repetitions predominant protein (GARP), Leucine-Rich Repeat-Containing Protein 33 (LRRC33), latent TGF-beta binding protein 1 (LTBP1), or latent TGF-beta binding protein 3 (LTBP3).
12. The method of claim 1 , wherein the TGFβ1-specific inhibitor is a neutralizing antibody, or antigen-binding fragment thereof.
13. A pharmaceutical composition produced by the method of claim 1 .
14. The method of claim 1 , wherein the TGFβ1-specific inhibitor cross-competes with an antibody, or antigen-binding fragment thereof, comprising six complementarity determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3,
wherein CDRH1 comprises an amino acid sequence as set forth in SEQ ID NO: 1 or SEQ ID NO: 2,
wherein CDRH2 comprises an amino acid sequence as set forth in SEQ ID NO :3 or SEQ ID NO:4,
wherein CDRH3 comprises an amino acid sequence as set forth in SEQ ID NO: 5 or SEQ ID NO: 6,
wherein CDRL1 comprises an amino acid sequence as set forth in SEQ ID NO: 7 or SEQ ID NO: 8,
wherein CDRL2 comprises an amino acid sequence as set forth in SEQ ID NO: 9 or SEQ ID NO: 10,
wherein CDRL3 comprises an amino acid sequence as set forth in SEQ ID NO: 11 or SEQ ID NO: 12.
15. The method of claim 1 , further comprising a step of:
selecting an antibody, or antigen-binding fragment thereof, that cross-competes with an antibody, or antigen-binding fragment thereof, comprising six complementarity determining regions (CDRs): CDRH1, CDRH2, CDRH3, CDRL1, CDRL2, and CDRL3,
wherein CDRH1 comprises an amino acid sequence as set forth in SEQ ID NO: 2,
wherein CDRH2 comprises an amino acid sequence as set forth in SEQ ID NO: 4,
wherein CDRH3 comprises an amino acid sequence as set forth in SEQ ID NO: 6,
wherein CDRL1 comprises an amino acid sequence as set forth in SEQ ID NO: 8,
wherein CDRL2 comprises an amino acid sequence as set forth in SEQ ID NO: 10,
wherein CDRL3 comprises an amino acid sequence as set forth in SEQ ID NO: 12.