Systemic nanoplasmid gene therapy with engineered cancer-activated promoters selectively programs tumor cells to express inflammatory interleukins and drive antitumor immunity

Background: Earli is developing an orthogonal genetic approach to cancer treatment with systemically delivered DNA nanoplasmids engineered with synthetic cancer-activated promoters (CAPs) to selectively express therapeutic payloads in malignant cells while remaining transcriptionally inert in healthy tissues. This selectivity concentrates encoded therapeutic activity within the tumor and concomitantly avoids systemic on-target, off-tumor toxicity. Here we describe the anti-tumor effects of CAPs driving expression of specific cytokines (i.e. IL-12), delivered IV using lipid nanoparticles (LNPs). Our data demonstrate tumor selective IL-12 expression with complete ablation of syngeneic tumor growth and minimal systemic IL-12 expression or IL-12 exposure in the serum. Methods: DNA Nanoplasmids were engineered for exquisite CAP specificity and validated for cytokine expression in tumor cell lines and for cytokine function in reporter cells and primary immune cells. LNP-formulated constructs were tested for in vivo distribution, efficacy, immune phenotyping and expression profiling in MB49 or B16F10 syngeneic tumor models. Results : CAP-cytokine constructs were expressed in tumor cell lines and produced cytokines with wild type activity. When administered IV, CAP-IL-12 LNPs but not control DNA-LNPs, induced dose-dependent, robust, durable anti-tumor activity. While tissue profiling demonstrated broad extra-hepatic biodistribution of the DNA template, IL-12 mRNA expression was exquisitely restricted to tumor tissue (12 other tissues tested similarly, although IL-12 protein was present tumor tissues, serum often below CAP-IL-12-treated mice demonstrated robust til cd4" and cd8 activation via upregulation of ki67 granzyme b. Furthermore, also upregulated mhc-i ii antigen presentation machinery multiple myeloid dc subsets, and, contrast with treatment, only gradually induced low levels systemic ifngamma without bodyweight loss or acute toxicity-associated nk cell hyperactivation. Conclusions: Here we describe a novel genetic approach to engage the immune system directly in the tumor microenvironment by reprogramming cancer cells to produce and secrete therapeutic cytokines directly into the TME. These efforts aim to reduce on-target, off-tumor effects and increase therapeutic window compared to systemically administered protein immune agonists. Future work includes expressing combinations of different payloads and multi-component modalities from the same genetic platform.