Breakthrough in Cancer Immunotherapy: Combinatorial Treatment Significantly Improves Tolerability Without Compromising Efficacy

Current research in cancer immunotherapy has revealed promising results in the administration of recombinant interleukin 2 (IL-2) fusion proteins. However, these treatments are often hindered by dose-limiting toxicities, including vascular leak syndrome. To address this issue, researchers from the University of Zurich have explored the therapeutic potential of co-administering signaling inhibitors with matched pharmacokinetic properties. The combinatorial treatment, consisting of a tumor-homing F8-IL2 fusion protein and upadacitinib, significantly improved tolerability without compromising therapeutic activity.

Key Takeaways:

• The administration of recombinant IL-2 fusion proteins can cause severe toxicities, including vascular leak syndrome, which can limit dose escalation.
• The combinatorial treatment of F8-IL2 with upadacitinib resulted in a significant reduction of systemic toxicity, allowing for the administration of potentially curative doses.
• The treatment protected mice from body weight loss, uncontrolled systemic cytokine release, and severe vascular leak syndrome manifestations.
• Immune profiling of tumors and secondary lymphoid organs revealed massive natural killer and cytotoxic T-cell infiltration.
• The study suggests that combinatorial treatments can enable the administration of targeted IL-2 products while sparing healthy organs from life-threatening toxicities.
• Researchers Francesco Prisco, Dario Neri, and colleagues explored the therapeutic potential of co-administering signaling inhibitors with matched pharmacokinetic properties.

Statistics:

• The study used tumor-homing F8-IL2 fusion protein and upadacitinib in combination to treat immunocompetent tumor-bearing mice.
• The combinatorial treatment resulted in a significant reduction of peripheral edema, cytokine levels, and histopathological analysis of vascular leak syndrome.
• The study showed improved tolerability without any detectable loss of therapeutic activity in mice.
• The treatment efficiently controlled tumor growth and retained immunological activity within the neoplastic mass.

Sources:

• Combinatorial treatment with upadacitinib abrogates systemic toxicity of a tumor-targeted IL-2 fusion protein. (Journal for ImmunoTherapy of Cancer, 2025, 13(5)).
• University of Zurich Researchers Advance Knowledge in Cancer Immunotherapy (Combinatorial treatment with upadacitinib abrogates systemic toxicity of a tumor-targeted IL-2 fusion protein). (Health & Medicine Week. May 30, 2025; p 6231).
• Francesco Prisco, et al. Laboratory for Animal Model Pathology, Institute of Veterinary Pathology, University of Zurich, Zurich, Switzerland.
• BMJ Publishing Group. (Publisher for Journal for ImmunoTherapy of Cancer).