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EP-4736955-A2 - EPCAM ANTIBODIES, ACTIVATABLE ANTIBODIES, AND IMMUNOCONJUGATES, AND USES THEREOF

EP4736955A2EP 4736955 A2EP4736955 A2EP 4736955A2EP-4736955-A2

Abstract

The disclosure generally relates to antibodies and antibody fragments that specifically bind human EpCAM, EpCAM activatable antibodies, and immunoconjugates thereof, as well as, methods of making and using the antibodies, antibody fragments, activatable antibodies, and immunoconjugates, for the diagnosis and treatment of diseases such as cancer.

Inventors

  • LIU, Yimao
  • CHAN, Chanty, Mariategue
  • FOX, Ellaine Anne, Mariano
  • HICKS, Stuart, W.
  • GUIDI, Cynthia, J.
  • KOHLI, NEERAJ
  • CHITTENDEN, THOMAS
  • LAMBERT, JOHN
  • PAIDHUNGAT, MADAN, M.
  • SAGERT, Jason, Gary
  • TIPTON, Kimberly, Ann

Assignees

  • ImmunoGen, Inc.
  • Cytomx Therapeutics, Inc.

Dates

Publication Date
20260506
Application Date
20191023

Claims (15)

  1. A method of producing an immunoconjugate comprising an EpCAM-binding agent (EpBA) comprising the step of reacting the EpBA with a cytotoxic agent-linker compound to produce the immunoconjugate, wherein the EpBA is an EpCAM antibody, EpCAM-binding antibody fragment, or EpCAM activatable antibody comprising a heavy chain CDR1 (VH-CDR1), a heavy chain CDR2 (VH-CDR2), a heavy chain CDR3 (VH-CDR3), a light chain CDR1 (VL-CDR1), a light chain CDR2 (VL-CDR2), and a light chain CDR3 (VL-CDR3) having the sequences selected from the group consisting of: (a) SEQ ID NOs: 13-15, 42, 40, and 41, respectively; (b) SEQ ID NOs: 13-15, and 39-41, respectively; (c) SEQ ID NOs: 13, 26, 15, and 39-41, respectively; and (d) SEQ ID NOs: 13, 26, 15, 42, 40, and 41, respectively.
  2. The method of claim 1, wherein the cytotoxic agent-linker compound is formed by the step of reacting the cytotoxic agent with a linker compound.
  3. The method of claim 2, wherein the cytotoxic agent comprises an amine reactive group.
  4. The method of claim 2, wherein the linker compound comprises an amine reactive group.
  5. The method of claim 2, wherein the linker compound comprises a thiol reactive group.
  6. The method of claim 2, wherein the linker compound comprises an amine reactive group and a thiol reactive group.
  7. The method of claim 1, wherein the immunoconjugate produced is represented by the following formula: wherein q is an integer from 1 to 10, and wherein q is conjugated to lysine residues of EpBA.
  8. The method of claim 7, wherein q is 3 or 4.
  9. The method of claim 1, wherein the cytotoxic agent-linker compound is formed by the step of reacting GMBS, represented by the formula a9L, with a maytansinoid compound represented by the formula (D-1) wherein D 1 is represented by the formula: wherein U is -H, wherein a maytansinoid-linker compound is formed as the cytotoxic agent-linker compound.
  10. The method of any one of claims 1 to 9, wherein the EpBA is: (a) an EpCAM activatable antibody; (b) an EpCAM antibody; or (c) an EpCAM-binding antibody fragment.
  11. The method of any one of claims 1 to 9, wherein the EpBA comprises: (a) a VH-CDR1 comprising the sequence NYYIH (SEQ ID NO:13); (b) a VH-CDR2 comprising the sequence WIYPGNVYIQYNEKFKG (SEQ ID NO:14); (c) a VH-CDR3 comprising the sequence DGPWFAY (SEQ ID NO:15); (d) a VL-CDR1 comprising the sequence RSSRSLLHSDGFTYLY (SEQ ID NO:42); (e) a VL-CDR2 comprising the sequence QTSNLAS (SEQ ID NO:40); and (f) a VL-CDR3 comprising the sequence AQNLELPNT (SEQ ID NO:41)
  12. The method of claim 11, wherein the EpBA is an EpCAM activatable antibody.
  13. The method of claim 11, wherein the EpBA is an EpCAM antibody.
  14. The method of claim 11, wherein the EpBA is an EpCAM-binding antibody fragment.
  15. The method of claim 12, wherein the EpCAM activatable antibody comprises: (a) a masking moiety (MM) coupled to the EpCAM antibody or EpCAM-binding antibody fragment thereof, wherein the masking moiety comprises the sequence WWPPCQGGAWCEQRI (SEQ ID NO:155); and (b) a cleavable moiety (CM) coupled to the EpCAM antibody or EpCAM-binding antibody fragment thereof, wherein the cleavable moiety comprises the sequence ISSGLLSGRSDNI (SEQ ID NO: 169).

Description

BACKGROUND The disclosure generally relates to antibodies and antibody fragments that specifically bind human EpCAM, EpCAM activatable antibodies, and immunoconjugates thereof, as well as, methods of making and using the antibodies, antibody fragments, activatable antibodies, and immunoconjugates, for the diagnosis and treatment of diseases such as cancer. Epithelial cell adhesion molecule (EpCAM), is a type I trans-membrane glycoprotein comprising an extracellular domain, a transmembrane domain, and a single intracellular domain. EpCAM expression in human is epithelia-specific. The majority of epithelial cells express EpCAM, except squamous epithelium and some specific epithelium cell types, such as epidermal keratinocytes, hepatocytes, gastric parietal cells, and myoepithelial cells (Balzar et al., J. Mol. Med. 77:699-712 (1999); Momburg et al., Cancer Res 47:2883-2891 (1987)). EpCAM is abundantly and homogeneously expressed on human carcinomas of different origins (Went et al., Br. J. Cancer 94:128-35 (2006); Herlyn et al., Proc Natl. Acad. Sci. USA 76:1438-1442 (1979); Went et al., Hum. Pathol. 35:122-128 (2004)). EpCAM is overexpressed in the vast majority of epithelial cancers, including for example, ovarian cancers, colon cancers, stomach cancers, prostate cancers, and lung cancers. In addition, EpCAM has been shown to be expressed on the majority of primary, metastatic, and disseminated NSCLC (non-small cell lung cancer cells) (Passlick, Int. J. Cancer 87:548-552 (2000)), on gastric and gastro-esophageal junction adenocarcinomas (Martin, J. Clin. Pathol. 52:701-704 (1999)) and in cell lines derived from colorectal, pancreatic carcinomas and breast carcinomas (Szala, Proc. Natl. Acad. Sci. USA 87:3542-3546 (1990), Packeisen, Hybridoma 18:37-40 (1999)). In another study, immunohistochemical analysis of 108 samples of secondary tumors has found that only 4% lacked EpCAM expression. EpCAM is overexpressed also in cancer-initiating or cancer stem cells isolated from colon, breast, pancreas and prostate carcinomas (O'Brien et al., Nature 445:106-110 (2007); Marhaba et al., Curr. Mol. Med. 8:784-804 (2008)). Normal cells express EpCAM on the basolateral side of the epithelial membrane, whereas cancer cells heavily express EpCAM on the apical surface. Antibody-based therapeutics have been designed to exploit this characteristic of EpCAM expression, as normal cellular EpCAM is less prominent and less exposed, meaning healthy cells may not be as susceptible to binding by therapeutic anti-EpCAM antibodies. A number of antibodies to EpCAM have been used in the clinic but failed for various reasons. The EpCAM antibodies tested take a number of formats, including naked antibodies, immunotoxins and bi- or tri-specific antibodies (Baeuerle, Br. J. Cancer, 96:417-423 (2007)). For example, adecatumumab (MT201), a naked anti-EpCAM antibody has been tested in clinical studies of treatment in colorectal, prostate and breast cancers. Safety issues facing the current anti-EpCAM antibody-based approaches include systemic intolerability and acute pancreatitis. Thus, although there have been several attempts to develop therapeutic antibodies to EpCAM, there is a significant need for the development of novel therapeutic EpCAM antibodies that overcome the shortcomings and limitations of the previously developed antibodies. BRIEF SUMMARY The disclosure provides antibodies and antibody fragments that specifically bind human EpCAM, as well as EpCAM activatable antibodies, and immunoconjugates comprising the antibodies, antibody fragments and activatable antibodies. Polynucleotides comprising nucleic acid sequences encoding the EpCAM antibodies, EpCAM-binding antibody fragments and activatable antibodies are also provided, as are vectors comprising the polynucleotides, and cells comprising the polynucleotides and vectors. The disclosure also provides compositions such as pharmaceutical compositions comprising the EpCAM antibodies, EpCAM-binding antibody fragments and activatable antibodies. Methods of making and using the EpCAM antibodies, EpCAM-binding antibody fragments, activatable antibodies, and compositions are further provided. Such methods include using the antibodies, antibody fragments, activatable antibodies, immunoconjugates and other compositions to inhibit tumor growth, as well as, methods of making and using the antibodies, antibody fragments, activatable antibodies, immunoconjugates, and compositions for the diagnosis and treatment of diseases such as cancer. In some embodiments, the disclosure provides: [1] an EpCAM antibody or EpCAM-binding antibody fragment, wherein the antibody or antibody fragment comprises: (a) a heavy chain CDR1 (VH-CDR1) comprising the sequence X1YX3X4H, wherein X1 is selected from N and S, X3 is selected from Y, N, F, S, H, D, L, I, and W, and X4 is selected from I and M (SEQ ID NO:5);(b) a heavy chain CDR2 (VH-CDR2) comprising the sequence WX2X3PGX6VYIQYX12X13KFX17G, wherein X2 is selecte