SON-1210 - a novel bifunctional IL-12 / IL-15 fusion protein that improves cytokine half-life, targets tumors, and enhances therapeutic efficacy

BackgroundThe potential synergy between interleukin-12 (IL-12) and IL-15 holds promise for more effective solid tumor immunotherapy. Nevertheless, previous clinical trials involving therapeutic cytokines have encountered obstacles such as short pharmacokinetics, limited tumor microenvironment (TME) targeting, and substantial systemic toxicity.MethodsTo address these challenges, we fused single-chain human IL-12 and native human IL-15 in cis onto a fully human albumin binding (FHAB) domain single-chain antibody fragment (scFv). This novel fusion protein, IL12-FHAB-IL15 (SON-1210), is anticipated to amplify the therapeutic impact of interleukins and combination immunotherapies in human TME. The molecule was studied in vitro and in animal models to assess its pharmacokinetics, potency, functional characteristics, safety, immune response, and efficacy.ResultsSON-1210 demonstrated robust binding affinity to albumin and exhibited the anticipated in vitro activity and tumor model efficacy that might be expected based on decades of research on native IL-12 and IL-15. Notably, in the B16F10 melanoma model (a non-immunogenic, relatively “cold” tumor), the murine counterpart of the construct, which had mouse (m) and human (h) cytokine sequences for the respective payloads (mIL12-FHAB-hIL15), outperformed equimolar doses of the co-administered native cytokines in a dose-dependent manner. A single dose caused a marked reduction in tumor growth that was concomitant with increased IFNγ levels; increased Th1, CTL, and activated NK cells; a shift in macrophages from the M2 to M1 phenotype; and a reduction in Treg cells. In addition, a repeat-dose non-human primate (NHP) toxicology study displayed excellent tolerability up to 62.5 µg/kg of SON-1210 administered three times, which was accompanied by the anticipated increases in IFNγ levels. Toxicokinetic analyses showed sustained serum levels of SON-1210, using a sandwich ELISA with anti-IL-15 for capture and biotinylated anti-IL-12 for detection, along with sustained IFNγ levels, indicating prolonged kinetics and biological activity.ConclusionCollectively, these findings support the suitability of SON-1210 for patient trials in terms of activity, efficacy, and safety, offering a promising opportunity for solid tumor immunotherapy. Linking cytokine payloads to a fully human albumin binding domain provides an indirect opportunity to target the TME using potent cytokines in cis that can redirect the immune response and control tumor growth

Low-Dose Pulsatile Interleukin-6 As a Treatment Option for Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) remains one of the most common and serious complications of diabetes. Currently, pharmacological agents are limited to treating the pain associated with DPN, and do not address the underlying pathological mechanisms driving nerve damage, thus leaving a significant unmet medical need. Interestingly, research conducted using exercise as a treatment for DPN has revealed interleukin-6 (IL-6) signaling to be associated with many positive benefits such as enhanced blood flow and lipid metabolism, decreased chronic inflammation, and peripheral nerve fiber regeneration. IL-6, once known solely as a pro-inflammatory cytokine, is now understood to signal as a multifunctional cytokine, capable of eliciting both pro- and anti-inflammatory responses in a context-dependent fashion. IL-6 released from muscle in response to exercise signals as a myokine and as such has a unique kinetic profile, whereby levels are transiently elevated up to 100-fold and return to baseline levels within 4 h. Importantly, this kinetic profile is in stark contrast to long-term IL-6 elevation that is associated with pro-inflammatory states. Given exercise induces IL-6 myokine signaling, and exercise has been shown to elicit numerous beneficial effects for the treatment of DPN, a causal link has been suggested. Here, we discuss both the clinical and preclinical literature related to the application of IL-6 as a treatment strategy for DPN. In addition, we discuss how IL-6 may directly modulate Schwann and nerve cells to explore a mechanistic understanding of how this treatment elicits a neuroprotective and/or regenerative response. Collectively, studies suggest that IL-6, when administered in a low-dose pulsatile strategy to mimic the body’s natural response to exercise, may prove to be an effective treatment for the protection and/or restoration of peripheral nerve function in DPN. This review highlights the studies supporting this assertion and provides rationale for continued investigation of IL-6 for the treatment of DPN