Abstract 4518: Pre-clinical development of NL-201: A de novo α-independent IL-2/IL-15 agonist

Abstract

Interleukin-2 (IL-2) and interleukin-15 (IL-15) promote anti-tumor immune activity by stimulating effector T and NK cells expressing the β and γ subunits of the IL-2 and IL-15 receptors. However, preferential activation of off-target cell populations expressing the high-affinity α subunit (including regulatory T cells, eosinophils, and endothelial cells) has limited the safety, therapeutic benefit, and widespread clinical use of these cytokines. Recently, we used sophisticated computational methods to create Neoleukin-2/15 (Neo-2/15), an entirely de novo α-independent agonist of both the IL-2 and IL-15 receptors. Unlike strategies that attempt to sterically inhibit or mutate the α-binding region of IL-2 or IL-15, Neo-2/15 was computationally designed to have no α-binding interface, while also having increased affinity for the β and γ signaling subunits. As a result, Neo-2/15 stimulates effector T and NK cells more potently and selectively than IL-2 or IL-15. Here, we report on the preclinical development and pharmacology of NL-201, a long-circulating variant of Neo-2/15 that is intended for clinical applications. NL-201 was derived from Neo-2/15 via the site-specific conjugation of a single PEG molecule and is manufactured using a simple and scalable process. NL-201 has a prolonged blood half-life and a sustained pharmacodynamic effect while retaining the high potency, selectivity, and thermodynamic stability of Neo-2/15. Preclinical studies demonstrate the robust antitumor activity of NL-201 as a single agent across a wide range of syngeneic murine tumor models, including those that do not respond well to checkpoint inhibitors. Due to its stability, high potency, and selectivity, NL-201 may overcome the long-standing challenges associated with the clinical use of IL-2 and IL-15 for cancer immunotherapy. Citation Format: Carl D. Walkey, Paul Hara, Laurie Tatalick, Umut Ulge, Jonathan Drachman, Daniel-Adriano Silva. Pre-clinical development of NL-201: A de novo α-independent IL-2/IL-15 agonist [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4518.

TransCon IL-2 β/γ: a novel long-acting prodrug with sustained release of an IL-2Rβ/γ-selective IL-2 variant with improved pharmacokinetics and potent activation of cytotoxic immune cells for the treatment of cancer

“…12 While several IL-2Rβ/γ-biased IL-2 molecules designed to more preferentially activate NK cells and CD8 + T cells have been described, most approaches still have limitations such as incomplete IL-2Rβ/γ selectivity, 13 14 reduced IL-2Rβ/γ potency 15 or high C max -mediated effects from delivery of fully bioactive agents. [15][16][17][18][19][20][21] Here we describe the creation of TransCon IL-2 β/γ, a novel long-acting prodrug with sustained release of a novel receptor-selective IL-2 variant (IL-2 β/γ). Thus, TransCon IL-2 β/γ was designed using two independent approaches to optimally address the limitations of IL-2 in cancer immunotherapy, namely avoiding activation of undesired IL-2Rα + cell types and poor PK properties (high C max and short half-life), by achieving controlled and prolonged exposure of IL-2 β/γ to safely and robustly activate lymphocytes with antitumor function including CD8 + T cells, γδ T cells and NK cells.…”

Spatiotemporally programming cytokine immunotherapies through protein engineering

“…These muteins still need to be combined with one of the half‐life extension techniques described in Section 2, which can present additional failure points. For example, while Neo‐2/15 was originally unmodified, NL‐201 was site‐specifically conjugated to a single PEG chain for improved half‐life and retention 75 . Even though approaches like PEGylation have been extensively studied, they can significantly alter behavior and present unknowns when translating promising preclinical work.…”

“…For example, while Neo-2/15 was originally unmodified, NL-201 was site-specifically conjugated to a single PEG chain for improved half-life and retention. 75 We refer readers to other reviews for details on the many other examples of cytokine engineering for cell therapies. 20 The previous examples have modified receptor affinity to isolate cytokine effects to specific cells, but with the purpose of maintaining the native downstream effects.…”