title: Cloning and characterization of novel tumor-targeting immunocytokines based on murine IL7.
abstract: We generated and characterized novel antibody-cytokine fusion proteins ("immunocytokines") based on murine interleukin-7 (IL7), an immunomodulatory protein which has previously shown anti-cancer activity in preclinical models and whose human counterpart is currently being investigated in clinical trials. The sequential fusion of the clinical-stage antibody fragment scFv(F8), specific to a tumor-associated splice isoform of fibronectin, yielded an immunocytokine (termed "F8-mIL7") of insufficient pharmaceutical quality and in vivo tumor targeting performance, with a striking dose dependence on tumor targeting selectivity. By contrast, a novel immunocytokine design (termed "F8-mIL7-F8"), in which two scFv moieties were fused at the N- and C-terminus of murine IL7, yielded a protein of excellent pharmaceutical quality and with improved tumor-targeting performance [tumor: blood ratio=16:1, 24h after injection]. Both F8-mIL7 and F8-mIL7-F8 could induce tumor growth retardation in immunocompetent mice, but were not able to eradicate F9 tumors. The combination of F8-mIL7-F8 with paclitaxel led to improved therapeutic results, which were significantly better compared to those obtained with saline treatment. The study indicates how the engineering of novel immunocytokine formats may help generate fusion proteins of acceptable pharmaceutical quality, for those immunomodulatory proteins which do not lend themselves to a direct fusion with antibody fragments.
authors.affiliation: Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Wolfgang-Pauli-Strasse, Zurich, Switzerland.
authors.forename: Nadine
authors.initials: N
authors.lastname: Pasche
authors.forename: Janine
authors.initials: J
authors.lastname: Woytschak
authors.forename: Sarah
authors.initials: S
authors.lastname: Wulhfard
authors.forename: Alessandra
authors.initials: A
authors.lastname: Villa
authors.forename: Katharina
authors.initials: K
authors.lastname: Frey
authors.forename: Dario
authors.initials: D
authors.lastname: Neri
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D006801:Humans; D015851:Interleukin-7 / Q000493:pharmacokinetics / Q000627:therapeutic use*; D007457:Iodine Radioisotopes; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy*; D017239:Paclitaxel / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000493:pharmacokinetics / Q000627:therapeutic use*; D057127:Single-Chain Antibodies / Q000276:immunology; D014018:Tissue Distribution / Q000187:drug effects
chemical_list: D015851:Interleukin-7; D007457:Iodine Radioisotopes; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D017239:Paclitaxel