Antibody-Directed Enzyme Prodrug Therapy (ADEPT) for Cancer

  • Surinder K. Sharma
  • Kenneth D. Bagshawe
Part of the Macromolecular Anticancer Therapeutics book series (CDD&D)


Antibody-directed enzyme prodrug therapy (ADEPT) is a system that aims to restrict the action of a high concentration of a cytotoxic drug to cancer sites. This is achieved by using an antibody (or antibody fragment) to deliver a non-human enzyme to cancer sites.

To avoid systemic toxicity, enzyme levels in blood must be very low at the time of prodrug administration. The rapid clearance of enzyme from blood may be achieved by either using a glycosylated fusion molecule or by addition of a second component that inactivates the enzyme before a non-toxic prodrug that is a substrate for the enzyme is given. The low molecular weight drug thus generated diffuses through the tumour mass but has a short half-life so that it does not reach normal cell renewal systems. Many pre-clinical studies using a variety of enzymes and prodrugs confirmed efficacy of this approach but only one system has progressed to clinical trials. These clinical studies identified new challenges that need to be addressed when developing new ADEPT systems.


Bacterial Enzyme Nitrogen Mustard Cytosine Deaminase Enzyme Conjugate Catalytic Antibody 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Antibody-directed enzyme prodrug therapy


Antibody–enzyme conjugate


Carcinoembryonic antigen


4-[(2-chloroethyl)(2-mesyloxyethyl) amino] benzoyl-l-glutamic acid


Benzoic acid mustard prodrug


(Carboxypeptidase G2)




Dimethyl sulphonic acid


18fluorine-labelled fluoro-deoxy glucose -positron emission tomography




human carboxylesterase


human chorionic gonadotropin


An anti-CEA scFv antibody


A recombinant fusion protein consisting of the anti-CEA scFv antibody MFE fused with enzyme carboxypeptidase G2


Maximal tolerable dose


SB43 galactosylated

Tag 72

Tumour-associated glycoprotein 72 antigen



We thank Professor Richard Begent for the critical review of this manuscript and Cancer Research UK for grant support.


  1. 1.
    Bagshawe KD (1987) Antibody directed enzymes revive anti-cancer prodrugs concept. Br J Cancer 56:531–532.PubMedGoogle Scholar
  2. 2.
    Bosslet K, Czech J, Lorenz P et al. (1992) Molecular and functional characterisation of a fusion protein suited for tumour specific prodrug activation. Br J Cancer 65:234–238.PubMedGoogle Scholar
  3. 3.
    Eccles SA, Court WJ, Box GA et al. (1994) Regression of established breast carcinoma xenografts with antibody-directed enzyme prodrug therapy against c-erbB2 p185. Cancer Res 54:5171–5177.PubMedGoogle Scholar
  4. 4.
    Rodrigues ML, Presta LG, Kotts CE et al. (1995) Development of a humanized disulfide-stabilized anti-p185HER2 Fv-beta-lactamase fusion protein for activation of a cephalosporin doxorubicin prodrug. Cancer Res 55:63–70.PubMedGoogle Scholar
  5. 5.
    Muraro R, Kuroki M, Wunderlich D et al. (1988) Generation and characterization of B72.3 second generation monoclonal antibodies reactive with the tumor-associated glycoprotein 72 antigen. Cancer Res 48:4588–4596.PubMedGoogle Scholar
  6. 6.
    Cheng TL, Chen BM, Chern JW et al. (2000) Efficient clearance of poly(ethylene glycol)-modified immunoenzyme with anti-PEG monoclonal antibody for prodrug cancer therapy. Bioconjug Chem 11:258–266.CrossRefPubMedGoogle Scholar
  7. 7.
    Alderson RF, Toki BE, Roberge M et al. (2006) Characterization of a CC49-based single-chain fragment-beta-lactamase fusion protein for antibody-directed enzyme prodrug therapy (ADEPT). Bioconjug Chem 17:410–418.CrossRefPubMedGoogle Scholar
  8. 8.
    Roberge M, Estabrook M, Basler J (2006) Construction and optimization of a CC49-based scFv-beta-lactamase fusion protein for ADEPT. Protein Eng Des Sel 19:141–145.CrossRefPubMedGoogle Scholar
  9. 9.
    Siemers NO, Kerr DE, Yarnold S et al. (1997) Construction, expression, and activities of L49-sFv-beta-lactamase, a single-chain antibody fusion protein for anticancer prodrug activation. Bioconjug Chem 8:510–519.CrossRefPubMedGoogle Scholar
  10. 10.
    Kerr DE, Li Z, Siemers NO et al. (1998) Development and activities of a new melphalan prodrug designed for tumor-selective activation. Bioconjug Chem 9:255–259.CrossRefPubMedGoogle Scholar
  11. 11.
    Senter PD, Springer CJ (2001) Selective activation of anticancer prodrugs by monoclonal antibody-enzyme conjugates. Adv Drug Deliv Rev 53:247–264.CrossRefPubMedGoogle Scholar
  12. 12.
    McDonagh CF, Beam KS, Wu GJ et al. (2003) Improved yield and stability of L49-sFv-beta-lactamase, a single-chain antibody fusion protein for anticancer prodrug activation, by protein engineering. Bioconjug Chem 14:860–869.CrossRefPubMedGoogle Scholar
  13. 13.
    Senter PD, Saulnier MG, Schreiber GJ (1988) Anti-tumor effects of antibody-alkaline phosphatase conjugates in combination with etoposide phosphate. Proc Natl Acad Sci U S A 85:4842–4846.CrossRefPubMedGoogle Scholar
  14. 14.
    Deckert PM, Bornmann WG, Ritter G et al. (2004) Specific tumour localisation of a huA33 antibody – carboxypeptidase A conjugate and activation of methotrexate-phenylalanine. Int J Oncol 24:1289–1295.PubMedGoogle Scholar
  15. 15.
    Rader C, Turner JM, Heine A et al. (2003) A humanized aldolase antibody for selective chemotherapy and adaptor immunotherapy. J Mol Biol 332:889–899.CrossRefPubMedGoogle Scholar
  16. 16.
    Abraham S, Guo F, Li LS et al. (2007) Synthesis of the next-generation therapeutic antibodies that combine cell targeting and antibody-catalyzed prodrug activation. Proc Natl Acad Sci U S A 104:5584–5589.CrossRefPubMedGoogle Scholar
  17. 17.
    Biela BH, Khawli LA, Hu P et al. (2003) Chimeric TNT-3/human beta-glucuronidase fusion proteins for antibody-directed enzyme prodrug therapy (ADEPT). Cancer Biother Radiopharm 18:339–353.CrossRefPubMedGoogle Scholar
  18. 18.
    Heinis C, Alessi P, Neri D (2004) Engineering a thermostable human prolyl endopeptidase for antibody-directed enzyme prodrug therapy. Biochemistry 43:6293–6303.CrossRefPubMedGoogle Scholar
  19. 19.
    Haisma HJ, Boven E, Van MM, de JJ et al. (1992) A monoclonal antibody-beta-glucuronidase conjugate as activator of the prodrug epirubicin-glucuronide for specific treatment of cancer. Br J Cancer 66:474–478.PubMedGoogle Scholar
  20. 20.
    Houba PH, Boven E, van der Meulen-Muileman IH et al. (2001) Pronounced antitumor efficacy of doxorubicin when given as the prodrug DOX-GA3 in combination with a monoclonal antibody beta-glucuronidase conjugate. Int J Cancer 91:550–554.CrossRefPubMedGoogle Scholar
  21. 21.
    Bosslet K, Czech J, Hoffmann D (1994) Tumor-selective prodrug activation by fusion protein-mediated catalysis. Cancer Res 54:2151–2159.PubMedGoogle Scholar
  22. 22.
    Senter PD, Beam KS, Mixan B et al. (2001) Identification and activities of human carboxylesterases for the activation of CPT-11, a clinically approved anticancer drug. Bioconjug Chem 12:1074–1080.CrossRefPubMedGoogle Scholar
  23. 23.
    Oosterhoff D, Pinedo HM, van der Meulen IH et al. (2002) Secreted and tumour targeted human carboxylesterase for activation of irinotecan. Br J Cancer 87:659–664.CrossRefPubMedGoogle Scholar
  24. 24.
    Wallace PM, Senter PD (1991) In vitro and in vivo activities of monoclonal antibody-alkaline phosphatase conjugates in combination with phenol mustard phosphate. Bioconjug Chem 2:349–352.CrossRefPubMedGoogle Scholar
  25. 25.
    Goshorn SC, Svensson HP, Kerr DE et al. (1993) Genetic construction, expression, and characterization of a single chain anti-carcinoma antibody fused to beta-lactamase. Cancer Res 53:2123–2127.PubMedGoogle Scholar
  26. 26.
    Wallace PM, MacMaster JF, Smith VF et al. (1994) Intratumoral generation of 5-fluorouracil mediated by an antibody-cytosine deaminase conjugate in combination with 5-fluorocytosine. Cancer Res 54:2719–2723.PubMedGoogle Scholar
  27. 27.
    Bagshawe KD The First Bagshawe lecture (1989) Towards generating cytotoxic agents at cancer sites. Br J Cancer 60:275–281.PubMedGoogle Scholar
  28. 28.
    Wentworth P, Datta A, Blakey D et al. (1996) Toward antibody-directed "abzyme" prodrug therapy, ADAPT: carbamate prodrug activation by a catalytic antibody and its in vitro application to human tumor cell killing. Proc Natl Acad Sci U S A 93:799–803.CrossRefPubMedGoogle Scholar
  29. 29.
    Rader C, Turner JM, Heine A et al. (2003) A humanized aldolase antibody for selective chemotherapy and adaptor immunotherapy. J Mol Biol 332:889–899.CrossRefPubMedGoogle Scholar
  30. 30.
    Shamis M, Lode HN, Shabat D (2004) Bioactivation of self-immolative dendritic prodrugs by catalytic antibody 38C2. J Am Chem Soc 126:1726–1731.CrossRefPubMedGoogle Scholar
  31. 31.
    Cesaro-Tadic S, Lagos D, Honegger A et al. (2003) Turnover-based in vitro selection and evolution of biocatalysts from a fully synthetic antibody library. Nat Biotechnol 21:679–685.CrossRefPubMedGoogle Scholar
  32. 32.
    Boger DL, Garbaccio RM (1999) A novel class of CC-1065 and duocarmycin analogues subject to mitomycin-related reductive activation. J Org Chem 64:8350–8362.CrossRefPubMedGoogle Scholar
  33. 33.
    Tietze LF, Lieb M, Herzig T et al. (2001) A strategy for tumor-selective chemotherapy by enzymatic liberation of seco-duocarmycin SA-derivatives from nontoxic prodrugs. Bioorg Med Chem 9:1929–1939.CrossRefPubMedGoogle Scholar
  34. 34.
    Tietze LF, Feuerstein T, Fecher A et al. (2002) Proof of principle in the selective treatment of cancer by antibody-directed enzyme prodrug therapy: the development of a highly potent prodrug. Angew Chem Int Ed Engl 41:759–761.CrossRefPubMedGoogle Scholar
  35. 35.
    Tietze LF, Feuerstein T (2003) Enzyme and proton-activated prodrugs for a selective cancer therapy. Curr Pharm Des 9:2155–2175.CrossRefPubMedGoogle Scholar
  36. 36.
    Kiakos K, Sato A, Asao T et al. (2007) DNA sequence selective adenine alkylation, mechanism of adduct repair, and in vivo antitumor activity of the novel achiral seco-amino-cyclopropylbenz[e]indolone analogue of duocarmycin AS-I-145. Mol Cancer Ther 6:2708–2718.CrossRefPubMedGoogle Scholar
  37. 37.
    Wang S, Liu D, Zhang X et al. (2007) Study on glycosylated prodrugs of toxoflavins for antibody-directed enzyme tumor therapy. Carbohydr Res 342:1254–1260.CrossRefPubMedGoogle Scholar
  38. 38.
    Jeffrey SC, Nguyen MT, Moser RF et al. (2007) Minor groove binder antibody conjugates employing a water soluble beta-glucuronide linker. Bioorg Med Chem Lett 17:2278–2280.CrossRefPubMedGoogle Scholar
  39. 39.
    Haisma HJ, Van MM, Pinedo HM, Boven E (1994) Comparison of two anthracycline-based prodrugs for activation by a monoclonal antibody-beta-glucuronidase conjugate in the specific treatment of cancer. Cell Biophys 24–25:185–192.PubMedGoogle Scholar
  40. 40.
    Leu YL, Roffler SR, Chern JW (1999) Design and synthesis of water-soluble glucuronide derivatives of camptothecin for cancer prodrug monotherapy and antibody-directed enzyme prodrug therapy (ADEPT). J Med Chem 42:3623–3628.CrossRefPubMedGoogle Scholar
  41. 41.
    Sagnou MJ, Howard PW, Gregson SJ et al. (2000) Design and synthesis of novel pyrrolobenzodiazepine (PBD) prodrugs for ADEPT and GDEPT. Bioorg Med Chem Lett 10:2083–2086.CrossRefPubMedGoogle Scholar
  42. 42.
    Masterson LA, Spanswick VJ, Hartley JA (2006) Synthesis and biological evaluation of novel pyrrolo[2,1-c][1,4]benzodiazepine prodrugs for use in antibody-directed enzyme prodrug therapy. Bioorg Med Chem Lett 16:252–256.CrossRefPubMedGoogle Scholar
  43. 43.
    Wells G, Martin CR, Howard PW et al. (2006) Design, synthesis, and biophysical and biological evaluation of a series of pyrrolobenzodiazepine-poly(N-methylpyrrole) conjugates. J Med Chem 49:5442–5461.CrossRefPubMedGoogle Scholar
  44. 44.
    Hao XK, Liu JY, Yue QH et al. (2006) In vitro and in vivo prodrug therapy of prostate cancer using anti-gamma-Sm-scFv/hCPA fusion protein. Prostate 66:858–866.CrossRefPubMedGoogle Scholar
  45. 45.
    Zou Y, Fu H, Ghosh S et al. (2004) Antitumor activity of hydrophilic Paclitaxel copolymer prodrug using locoregional delivery in human orthotopic non-small cell lung cancer xenograft models. Clin Cancer Res 10:7382–7391.CrossRefPubMedGoogle Scholar
  46. 46.
    Wrasidlo W, Gaedicke G, Guy RK et al. (2002) A novel 2'-(N-methylpyridinium acetate) prodrug of paclitaxel induces superior antitumor responses in preclinical cancer models. Bioconjug Chem 13:1093–1099.CrossRefPubMedGoogle Scholar
  47. 47.
    Svensson HP, Frank IS, Berry KK et al. (1998) Therapeutic effects of monoclonal antibody-beta-lactamase conjugates in combination with a nitrogen mustard anticancer prodrug in models of human renal cell carcinoma. J Med Chem 41:1507–1512.CrossRefPubMedGoogle Scholar
  48. 48.
    Grant JW, Smyth TP (2004) Toward the development of a cephalosporin-based dual-release prodrug for use in ADEPT. J Org Chem 69:7965–7970.CrossRefPubMedGoogle Scholar
  49. 49.
    Sherwood RF, Melton RG, Alwan SM et al. (1985) Purification and properties of carboxypeptidase G2 from Pseudomonas sp. strain RS-16. Use of a novel triazine dye affinity method. Eur J Biochem 148:447–453.CrossRefPubMedGoogle Scholar
  50. 50.
    Searle F, Bier C, Buckley RG et al. (1986) The potential of carboxypeptidase G2-antibody conjugates as anti-tumour agents. I. Preparation of antihuman chorionic gonadotrophin-carboxypeptidase G2 and cytotoxicity of the conjugate against JAR choriocarcinoma cells in vitro. Br J Cancer 53:377–384.PubMedGoogle Scholar
  51. 51.
    Melton RG, Boyle JM, Rogers GT et al. (1993) Optimisation of small-scale coupling of A5B7 monoclonal antibody to carboxypeptidase G2. J Immunol Methods 158:49–56.CrossRefPubMedGoogle Scholar
  52. 52.
    Springer CJ, Antoniw P, Bagshawe KD et al. (1990) Novel prodrugs which are activated to cytotoxic alkylating agents by carboxypeptidase G2. J Med Chem 33:677–681.CrossRefPubMedGoogle Scholar
  53. 53.
    Springer CJ, Bagshawe KD, Sharma SK et al. (1991) Ablation of human choriocarcinoma xenografts in nude mice by antibody-directed enzyme prodrug therapy (ADEPT) with three novel compounds. Eur J Cancer 27:1361–1366.CrossRefPubMedGoogle Scholar
  54. 54.
    Sharma SK, Bagshawe KD, Burke PJ et al. (1990) Inactivation and clearance of an anti-CEA carboxypeptidase G2 conjugate in blood after localisation in a xenograft model. Br J Cancer 61:659–662.PubMedGoogle Scholar
  55. 55.
    Sharma SK, Bagshawe KD, Springer CJ et al. (1991) Antibody directed enzyme prodrug therapy (ADEPT): a three phase system. Dis Markers 9:225–231.PubMedGoogle Scholar
  56. 56.
    Sharma SK, Boden JA, Springer CJ et al. (1994) Antibody-directed enzyme prodrug therapy (ADEPT): A three-phase study in ovarian tumor xenografts. Cell Biophys 24–25:219–228.PubMedGoogle Scholar
  57. 57.
    Bagshawe KD, Sharma SK, Springer CJ et al. (1995)Antibody-directed enzyme prodrug therapy: a pilot scale clinical trial. Tumor Targeting 1:17–29.Google Scholar
  58. 58.
    Bagshawe KD, Begent RHJ (1996) First clinical experience with ADEPT. Adv Drug Deliv Rev 22:365–367.CrossRefGoogle Scholar
  59. 59.
    Springer CJ, Poon GK, Sharma SK, Bagshawe KD (1993) Identification of prodrug, active drug, and metabolites in an ADEPT clinical study. Cell Biophys 22:9–26.PubMedGoogle Scholar
  60. 60.
    Napier MP, Sharma SK, Springer CJ et al. (2000) Antibody-directed enzyme prodrug therapy: efficacy and mechanism of action in colorectal carcinoma. Clin Cancer Res 6:765–772.PubMedGoogle Scholar
  61. 61.
    Martin J, Stribbling SM, Poon GK et al. (1997) Antibody-directed enzyme prodrug therapy: pharmacokinetics and plasma levels of prodrug and drug in a phase I clinical trial. Cancer Chemother Pharmacol 40:189–201.CrossRefPubMedGoogle Scholar
  62. 62.
    Springer CJ, Dowell R, Burke PJ et al. (1995) Optimization of alkylating agent prodrugs derived from phenol and aniline mustards: a new clinical candidate prodrug (ZD2767) for antibody-directed enzyme prodrug therapy (ADEPT). J Med Chem 38:5051–5065.CrossRefPubMedGoogle Scholar
  63. 63.
    Blakey DC, Burke PJ, Davies DH et al. (1996) ZD2767, an improved system for antibody-directed enzyme prodrug therapy that results in tumor regressions in colorectal tumor xenografts. Cancer Res 56:3287–3292.PubMedGoogle Scholar
  64. 64.
    Francis RJ, Sharma SK, Springer C et al. (2002) A phase I trial of antibody directed enzyme prodrug therapy (ADEPT) in patients with advanced colorectal carcinoma or other CEA producing tumours. Br J Cancer 87:600–607.CrossRefPubMedGoogle Scholar
  65. 65.
    Neuberger MS, Williams GT, Fox RO (1984) Recombinant antibodies possessing novel effector functions. Nature 312:604–608.CrossRefPubMedGoogle Scholar
  66. 66.
    Chester K, Pedley B, Tolner B et al. (2004) Engineering antibodies for clinical applications in cancer. Tumour Biol 25:91–98.CrossRefPubMedGoogle Scholar
  67. 67.
    Bhatia J, Sharma SK, Chester KA et al. (2000) Catalytic activity of an in vivo tumor targeted anti-CEA scFv::carboxypeptidase G2 fusion protein. Int J Cancer 85:571–577.CrossRefPubMedGoogle Scholar
  68. 68.
    Medzihradszky KF, Spencer DI, Sharma SK et al. (2004) Glycoforms obtained by expression in Pichia pastoris improve cancer targeting potential of a recombinant antibody-enzyme fusion protein. Glycobiology 14:27–37.CrossRefPubMedGoogle Scholar
  69. 69.
    Sharma SK, Pedley RB, Bhatia J et al. (2005) Sustained tumor regression of human colorectal cancer xenografts using a multifunctional mannosylated fusion protein in antibody-directed enzyme prodrug therapy. Clin Cancer Res 11:814–825.PubMedGoogle Scholar
  70. 70.
    Mayer A, Francis RJ, Sharma SK et al. (2006) A phase I study of single administration of antibody-directed enzyme prodrug therapy with the recombinant anti-carcinoembryonic antigen antibody-enzyme fusion protein MFECP1 and a bis-iodo phenol mustard prodrug. Clin Cancer Res 12:6509–6516.CrossRefPubMedGoogle Scholar
  71. 71.
    Wilkins DK, Mayer A, Sharma S et al. (2008) Evidence of efficacy of antibody directed enzyme prodrug therapy (ADEPT) in a phase I trial in patients with advanced carcinoma. AACR Meeting Abstracts, Apr 2008::LB-200.Google Scholar
  72. 72.
    Green AJ, Francis RJ, Baig S, Begent RH (2008) Semiautomatic volume of interest drawing for (18)F-FDG image analysis-method and preliminary results. Eur J Nucl Med Mol Imaging 35:393–406.CrossRefPubMedGoogle Scholar
  73. 73.
    Sharma SK, Bagshawe KD, Melton RG et al. (1992) Human immune response to monoclonal antibody-enzyme conjugates in ADEPT pilot clinical trial. Cell Biophys 21:109–120.PubMedGoogle Scholar
  74. 74.
    Bagshawe KD, Sharma SK (1996) Cyclosporine delays host immune response to antibody enzyme conjugate in ADEPT. Transplant Proc 28:3156–3158.PubMedGoogle Scholar
  75. 75.
    Spencer DI, Robson L, Purdy D et al. (2002) A strategy for mapping and neutralizing conformational immunogenic sites on protein therapeutics. Proteomics 2:271–279.CrossRefPubMedGoogle Scholar
  76. 76.
    Mayer A, Sharma SK, Tolner B et al. (2004) Modifying an immunogenic epitope on a therapeutic protein: a step towards an improved system for antibody-directed enzyme prodrug therapy (ADEPT). Br J Cancer 90:2402–2410.PubMedGoogle Scholar
  77. 77.
    Chester KA, Baker M, Mayer A (2005) Overcoming the immunological response to foreign enzymes in cancer therapy. Expert Rev Clin Immunol 4:549–559.CrossRefGoogle Scholar
  78. 78.
    Harding FA, Liu AD, Stickler M et al. (2005) A beta-lactamase with reduced immunogenicity for the targeted delivery of chemotherapeutics using antibody-directed enzyme prodrug therapy. Mol Cancer Ther 4:1791–1800.CrossRefPubMedGoogle Scholar
  79. 79.
    Cesaro-Tadic S, Lagos D, Honegger A et al. (2003) Turnover-based in vitro selection and evolution of biocatalysts from a fully synthetic antibody library. Nat Biotechnol 21:679–685.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.CR UK Targeting & Imaging Group, Res Department of OncologyUCL Cancer InstituteLondonUK
  2. 2.Department of Medical OncologyImperial College LondonLondonUK

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