Engineered cytokine/antibody fusion proteins improve delivery of IL-2 to pro-inflammatory cells and promote antitumor activity

Leonard, E. K.; Tomala, J.; Leff, M. I.; Lin, J.-X.; Lin, P.; Porter, M. J.; Johansen, E. R.; Thompson, L.; Cao, S. D.; Henclova, T.; Huliciak, M.; Vanek, O.; Kovar, M.; Leonard, W. J.; Spangler, J. B.

doi:10.1101/2023.05.03.539272

bioRxiv · 10.1101/2023.05.03.539272

Engineered cytokine/antibody fusion proteins improve delivery of IL-2 to pro-inflammatory cells and promote antitumor activity

Leonard, E. K.·Tomala, J.·Leff, M. I.·Lin, J.-X.·Lin, P.·Porter, M. J.·Johansen, E. R.·Thompson, L.·Cao, S. D.·Henclova, T.·Huliciak, M.·Vanek, O.·Kovar, M.·Leonard, W. J.·Spangler, J. B.

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Abstract

Progress in cytokine engineering is driving therapeutic translation by overcoming the inherent limitations of these proteins as drugs. The interleukin-2 (IL-2) cytokine harbors great promise as an immune stimulant for cancer treatment. However, the cytokines concurrent activation of both pro-inflammatory immune effector cells and anti-inflammatory regulatory T cells, its toxicity at high doses, and its short serum half-life have limited clinical application. One promising approach to improve the selectivity, safety, and longevity of IL-2 is complexation with anti-IL-2 antibodies that bias the cytokine towards the activation of immune effector cells (i.e., effector T cells and natural killer cells). Although this strategy shows therapeutic potential in preclinical cancer models, clinical translation of a cytokine/antibody complex is complicated by challenges in formulating a multi-protein drug and concerns about complex stability. Here, we introduce a versatile approach to designing intramolecularly assembled single-agent fusion proteins (immunocytokines, ICs) comprising IL-2 and a biasing anti-IL-2 antibody that directs the cytokines activities towards immune effector cells. We establish the optimal IC construction and further engineer the cytokine/antibody affinity to improve immune biasing function. We demonstrate that our IC preferentially activates and expands immune effector cells, leading to superior antitumor activity compared to natural IL-2 without inducing toxicities associated with IL-2 administration. Collectively, this work presents a roadmap for the design and translation of immunomodulatory cytokine/antibody fusion proteins. One Sentence SummaryWe developed an IL-2/antibody fusion protein that expands immune effector cells and shows superior tumor suppression and toxicity profile versus IL-2.

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Leonard, E. K., Tomala, J., Leff, M. I., Lin, J.-X., Lin, P., Porter, M. J., Johansen, E. R., Thompson, L., Cao, S. D., Henclova, T., Huliciak, M., Vanek, O., Kovar, M., Leonard, W. J., Spangler, J. B.. 2023-05-04. Engineered cytokine/antibody fusion proteins improve delivery of IL-2 to pro-inflammatory cells and promote antitumor activity. https://doi.org/10.1101/2023.05.03.539272

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