The antibody-based delivery of interleukin-12 to the tumor neovasculature eradicates murine models of cancer in combination with paclitaxel.
OBJECTIVE
Interleukin-12 (IL12) is a potent proinflammatory cytokine with antitumor activity. Its heterodimeric nature makes it compatible with a large variety of different immunocytokine formats. Here we report the design, production, and characterization of a novel immunocytokine, based on the fusion of the F8 antibody (specific to the alternatively spliced EDA domain of fibronectin, a marker of tumor neovasculature) with IL12 (termed IL12-F8-F8).


METHODS
We developed a novel immunocytokine based on the sequential fusion of interleukin-12 as a single polypeptide with two F8 antibodies in single-chain Fv (scFv) format. The fusion protein was characterized in vitro, and its targeting performance was assessed in vivo. The immunocytokine antitumor activity was studied as monotherapy as well as in combination therapies in three different murine tumor models. Moreover, depletion experiments and tumor analysis revealed a dominant role of natural killer cells for the mechanism of action.


RESULTS
IL12-F8-F8 can be produced in mammalian cells, yielding a product of good pharmaceutical quality, capable of selective localization on the tumor neovasculature in vivo, as judged by quantitative biodistribution analysis with radioiodinated protein preparations. The protein potently inhibited tumor growth in three different immunocompetent syngeneic models of cancer. The treatment was generally well tolerated. Moreover, the IL12-F8-F8 fusion protein could be produced both with murine IL12 (mIL12) and with human IL12 (hIL12).


CONCLUSIONS
The potent antitumor activity of mIL12-F8-F8, studied alone or in combination with paclitaxel in different tumor models, paves the way to the clinical development of the fully human immunocytokine.
Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.
Nadine
N
Pasche
Sarah
S
Wulhfard
Francesca
F
Pretto
Elisa
E
Carugati
Dario
D
Neri
D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D016466:CHO Cells; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood / Q000276:immunology; D018664:Interleukin-12 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D057507:Mice, 129 Strain; D008807:Mice, Inbred BALB C; D009369:Neoplasms / Q000098:blood supply / Q000188:drug therapy* / Q000276:immunology*; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000276:immunology; D017239:Paclitaxel / Q000008:administration & dosage; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000276:immunology* / Q000493:pharmacokinetics; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014018:Tissue Distribution; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects / Q000276:immunology
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C528643:F8 monoclonal antibody; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D018664:Interleukin-12; D007371:Interferon-gamma; D017239:Paclitaxel