591 Collagen targeting IL-12 combined with doxorubicin enhances the anti-tumor effect against osteosarcoma
Year: 2026
Type: conference-abstract
Abstract: Background Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents, and survival for metastatic disease remains 20 – 30%. 1 Doxorubicin (Dox), a standard agent, induces immunogenic cell death, but the immunosuppressive, immunologically cold tumor microenvironment (TME) limits its efficacy.2 Combination therapy with interleukin-12 (IL-12) can potentially reshape the TME, yet systemic delivery of IL-12 is constrained by dose-limiting toxicity.3 We previously showed that the A3 collagen-binding domain (CBD) of von Willebrand factor targets tumor collagen I and III, and that CBD-fused IL-12 (CBD-IL-12) localizes to tumors.4 5 Because the OS TME is collagen-rich,6 we hypothesized that CBD-IL-12, alone and with Dox, would be efficacious in OS.Methods Collagen expression in human OS was assessed using public transcriptomic dataset (GEO GSE99671, GSE14359) and by immunofluorescence staining of human and murine OS tissue. Recombinant CBD-IL-12 and unmodified IL-12 were produced in HEK293F cells. Tumor accumulation, biodistribution, anti-tumor efficacy, survival, and immune profiling by flow cytometry were evaluated in two syngeneic models, which are BVM03O (primary, p53-mutant) and K7M2, as subcutaneous tumors, with K7M2 also used as an experimental lung-metastasis model. Comprehensive systemic toxicity including plasma interferon-gamma (IFN-γ) was evaluated using healthy mice to determine the addition dox does not modulate safety profile.Results Collagen type I and III were abundant in human and murine OS. CBD-IL-12 achieved 4-fold higher tumor accumulation than unmodified IL-12 without increased off-target uptake, and selectively accumulated in K7M2 lung metastases but not in healthy lung ( figure 1). Although Dox monotherapy did not suppress tumor growth, CBD-IL-12 plus Dox significantly prolonged median survival in both subcutaneous models and reduced K7M2 lung-metastatic burden to near-healthy levels (figure 2). Mechanistically, the combination therapy expanded cytotoxic KLRG1+CD127−CD8+ T cells and XCR1+ type-1 conventional dendritic cells and increased the M1/M2 macrophage ratio (figure 2). CBD fusion held plasma IFN-γ ~10-fold below unmodified IL-12, suggesting that adding Dox did not compromise this safety profile (figure 2).Conclusions Collagen targeted CBD-IL-12 concentrates IL-12 within OS TME and modulates the cold immune state to active anti-tumor immunity. Combined with Dox, it overcomes the limitations of single-agent therapy, controls established lung metastases, and preserves a favorable safety margin, supporting CBD-IL-12 plus Dox as a clinically translatable chemo-immunotherapy for OS.Acknowledgements We thank Research Histology Facility at National Heart and Lung Institute for its support. This research was funded in part by Sarcoma UK, Bone Cancer Research Trust and Hannah’s Willberry Wonder Pony Charity, Pancreatic Cancer Research Fund, and The Brain Tumour Charity.References Mirabello L, Troisi RJ, Savage SA. Osteosarcoma incidence and survival rates from 1973 to 2004: data from the surveillance, epidemiology, and end results program. Cancer 2009;115:1531–1543.Tacar O, Sriamornsak P, Dass CR. Doxorubicin: an update on anticancer molecular action, toxicity and novel drug delivery systems. J Pharm Pharmacol. 2013;65:157–170.Brunda MJ, Luistro L, Warrier RR, Wright RB, Hubbard BR, Murphy M, et al. Antitumor and antimetastatic activity of interleukin 12 against murine tumors. J Exp Med. 1993;178:1223–1230.Mansurov A, Ishihara J, Hosseinchi P, Potin L, Marchell TM, Ishihara A, et al. Collagen-binding IL-12 enhances tumour inflammation and drives the complete remission of established immunologically cold mouse tumours. Nat Biomed Eng. 2020;4:531–543.Matsuo T, Noblecourt L, Kaur P, Wang C, Chiu PC, Sasaki K, et al. Collagen targeting IL-12 combined with doxorubicin enhances the anti-tumor effect against osteosarcoma. bioRxiv 2026; doi: 10.64898/2026.05.07.723520.Corre I, Verrecchia F, Crenn V, Redini F, Trichet V. The osteosarcoma microenvironment: a complex but targetable ecosystem. Cells 2020;9:976.Ethics Approval All animal experiments were approved by the ethical committees of Imperial College London and performed under a UK Home Office project license in accordance with the Animals (Scientific Procedures) Act 1986.Abstract 591 Figure 1Collagen-targeted CBD-IL-12 accumulates within primary and metastatic osteosarcomaAbstract 591 Figure 2CBD-IL-12 combined with doxorubicin prolongs survival, remodels anti-tumor immunity and preserves a favorable safety profile
Authors: Takumi Matsuo, Paul H Huang, Jun Ishihara
Institutions: Institute of Cancer Research, Imperial College London
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,490
OpenAlex ID: W7225329972