Targeting an engineered cytokine with interleukin-2 and interleukin-15 activity to the neovasculature of solid tumors

A De Novo Strategy To Improve Pharmacokinetics of Proteins from mRNA Therapeutics via Zwitterionic Polypeptide Fusion

Achieving therapeutic efficacy in protein replacement therapies requires sustaining pharmacokinetic (PK) profiles, while maintaining the bioactivity of circulating proteins. This is often achieved via PEGylation in protein-based therapies, but it remains challenging for proteins produced in vivo in mRNA-based therapies due to the lack of a suitable post-translational modification method. To address this issue, we integrated a genetically encoded zwitterionic polypeptide, EKP, into mRNA constructs to enhance the PK properties of product proteins. Composed of alternating glutamic acid (E), lysine (K), and proline (P), EKP exhibits unique superhydrophilic properties and low immunogenicity. Our results demonstrate that EKP fusion significantly extends the circulation half-life of proteins expressed from mRNA while preserving their bioactivity using human interferon alpha and Neoleukin-2/15 as examples. This EKP fusion technology offers a new approach to overcoming the current limitations in mRNA therapeutics and has the potential to significantly advance the development of mRNA-based protein replacement therapy.

The role of TNC in atherosclerosis and drug development opportunities

Tenascin C (TNC), a rich glycoprotein of the extracellular matrix, exhibits a pro-atherosclerosis or anti-atherosclerosis effect depending on its location. TNC, especially its C domain/isoform (TNC-C), is strongly overexpressed in atherosclerotic plaque active areas but virtually undetectable in most normal adult tissues, suggesting that TNC is a promising delivery vector target for atherosclerosis-targeted drugs. Many delivery vectors were investigated by recognizing TNC-C, including G11, G11-iRGD, TN11, PL1, and PL3. F16 and FNLM were also investigated by recognizing TNC-A1 and TNC, respectively. Notably, iRGD was undergoing clinical trials. PL1 not only recognizes TNC-C but also the extra domain-B (EDB) of fibronectin (FN), which is also a promising delivery vector for atherosclerosis-targeted drugs, and several conjugate agents are undergoing clinical trials. The F16-conjugate agent F16IL2 is undergoing clinical trials. Therefore, G11-iRGD, PL1, and F16 have great development value. Furthermore, ATN-RNA and IMA950 were investigated in clinical trials as therapeutic drugs and vaccines by targeting TNC, respectively. Therefore, targeting TNC could greatly improve the success rate of atherosclerosis-targeted drugs and/or specific drug development. This review discussed the role of TNC in atherosclerosis, atherosclerosis-targeted drug delivery vectors, and agent development to provide knowledge for drug development targeting TNC.

Site-Specific Chemical Modification of a Cytokine Mimic for Small Molecule-Based Tumor Targeting

The targeted delivery of bioactive proteins, such as cytokines, for cancer immunotherapy approaches mostly relies on antibodies or antibody fragments. However, fusion proteins may display low tissue penetration due to a large molecular size. Small molecule ligands with high affinity toward tumor-associated antigens provide a promising alternative for the selective delivery of cytokines to tumor lesions. We developed a one-pot procedure for the site-specific thiazolidine formation between an aldehyde bearing small molecule and the in situ generated N-terminal cysteine of a bioactive protein. Thereby, neoleukin-2/15 (Neo-2/15), a computationally engineered interleukin-2 and -15 mimic, was chemically conjugated to acetazolamide plus, a potent carbonic anhydrase IX (CAIX) ligand. The conjugate retained the biological activity of Neo-2/15 and revealed its ability to accumulate in renal cell carcinoma (SK-RC-52) xenografts upon systemic intravenous administration. The results highlight the potential of small molecule targeting moieties to drive the accumulation of a protein cargo to the respective disease site while conserving the small construct size.

A split, conditionally active mimetic of IL-2 reduces the toxicity of systemic cytokine therapy

The therapeutic potential of recombinant cytokines has been limited by the severe side effects of systemic administration. We describe a strategy to reduce the dose-limiting toxicities of monomeric cytokines by designing two components that require colocalization for activity and that can be independently targeted to restrict activity to cells expressing two surface markers. We demonstrate the approach with a previously designed mimetic of cytokines interleukin-2 and interleukin-15-Neoleukin-2/15 (Neo-2/15)-both for trans-activating immune cells surrounding targeted tumor cells and for cis-activating directly targeted immune cells. In trans-activation mode, tumor antigen targeting of the two components enhanced antitumor activity and attenuated toxicity compared with systemic treatment in syngeneic mouse melanoma models. In cis-activation mode, immune cell targeting of the two components selectively expanded CD8+ T cells in a syngeneic mouse melanoma model and promoted chimeric antigen receptor T cell activation in a lymphoma xenograft model, enhancing antitumor efficacy in both cases.