title: A novel AML-selective TRAIL fusion protein that is superior to Gemtuzumab Ozogamicin in terms of in vitro selectivity, activity and stability.
abstract: Gemtuzumab ozogamicin (GO, Mylotarg) is a targeted therapeutic agent in which an anti-CD33 antibody is chemically coupled to a highly cytotoxic calicheamicin derivative through a hydrolysable linker. GO has improved the treatment outcome for a subgroup of acute myeloid leukemia (AML) patients, but its use is associated with severe myelosuppression and hepatotoxicity. Here, we report on a novel anti-leukemia agent, designated scFvCD33:sTRAIL, in which an anti-CD33 single chain fragment of variable regions (scFv) antibody fragment is genetically linked to soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL). Normal CD33-positive monocytes were fully resistant to prolonged treatment with scFvCD33:sTRAIL, whereas treatment with GO resulted in substantial cytotoxicity. The activity of scFvCD33:sTRAIL towards AML cells was up to 30-fold higher than GO. The CD33-restricted anti-leukemia activity of scFvCD33:sTRAIL remained stable during prolonged storage at 37 degrees C, whereas GO showed a rapid increase in CD33-independent cytotoxicity. Moreover, scFvCD33:sTRAIL showed potent anti-leukemia activity towards CD33+ CML cells when treatment was combined with the Bcr-Abl tyrosine kinase inhibitor, Gleevec. Importantly, ex vivo treatment of patient-derived CD33+ AML tumor cells with scFvCD33:sTRAIL resulted in potent apoptosis induction that was enhanced by valproic acid, mitoxantrone and 17-(Allylamino)-17-demethoxygeldanamycin (17-AAG). Taken together, scFvCD33:sTRAIL is superior to GO in terms of tumor selectivity, activity and stability, warranting its further development for the treatment of CD33-positive leukemias.
authors.affiliation: Laboratory for Tumor Immunology, Department of Pathology & Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: ten Cate
authors.forename: E
authors.initials: E
authors.lastname: Bremer
authors.forename: M
authors.initials: M
authors.lastname: de Bruyn
authors.forename: T
authors.initials: T
authors.lastname: Bijma
authors.forename: D
authors.initials: D
authors.lastname: Samplonius
authors.forename: M
authors.initials: M
authors.lastname: Schwemmlein
authors.forename: G
authors.initials: G
authors.lastname: Huls
authors.forename: G
authors.initials: G
authors.lastname: Fey
authors.forename: W
authors.initials: W
authors.lastname: Helfrich
mesh_terms: D000208:Acute Disease; D000617:Aminoglycosides / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D024201:Bystander Effect; D002478:Cells, Cultured / Q000187:drug effects; D016503:Drug Delivery Systems; D004354:Drug Screening Assays, Antitumor; D004355:Drug Stability; D004789:Enzyme Activation / Q000187:drug effects; D000079982:Gemtuzumab; D006801:Humans; D007951:Leukemia, Myeloid / Q000473:pathology; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D009363:Neoplasm Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000494:pharmacology*; D063268:Sialic Acid Binding Ig-like Lectin 3; D057127:Single-Chain Antibodies; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000617:Aminoglycosides; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000970:Antineoplastic Agents; C571163:CD33 protein, human; D009363:Neoplasm Proteins; D011993:Recombinant Fusion Proteins; D063268:Sialic Acid Binding Ig-like Lectin 3; D057127:Single-Chain Antibodies; C543637:scFvCD33-sTRAIL protein; D000079982:Gemtuzumab