In Situ Tumor Vaccination with a Nano-oligo Therapeutic to Induce Whole-body Antitumor Immune Response

意义/目标。尽管免疫检查点抑制剂（ICI）在黑色素瘤患者中显示出令人印象深刻的结果，但大多数患者未能应答，主要是由于缺乏肿瘤浸润性T细胞。为了增强抗肿瘤T细胞库，我们开发了一种新型免疫纳米颗粒，称为“增强免疫应答和抑制肿瘤抑制环境- AIRISE-02”，其基于我们正在申请专利的纳米颗粒（NP），共递送免疫活化CpG寡核苷酸和针对STAT 3的siRNA。AIRISE-02依赖于“原位肿瘤疫苗接种”，它利用局部治疗的肿瘤来引发针对全身肿瘤的免疫反应。AIRISE-02的独特之处在于能够进入癌症和抗原呈递细胞（例如，DC，巨噬细胞）在瘤内（i.t.）注射，导致癌细胞死亡和肿瘤抗原释放，同时对抗原呈递细胞安全并激活抗原呈递细胞。通过用siRNA敲低STAT 3，AIRISE-02还调节肿瘤的免疫抑制环境。鉴于i.t.对于仅一种黑色素瘤肿瘤，AIRISE-02在治疗和未治疗的远处肿瘤中均引起消退，证明了全身免疫抑制作用。AIRISE-02与两种ICI（PD-1 + CTLA- 4，i. p.）当给予ICI时，8只小鼠中有5只完全治愈。这些小鼠至少在17个月内保持无肿瘤状态，而仅接受ICIs的小鼠在2个月内无法存活。AIRISE-02在结肠癌和乳腺癌小鼠模型中也有效，并且在猴子中耐受良好。Approach.这一直接的第二阶段SBIR侧重于AIRISE-02的IND使能研究。在目标1中，我们将通过鉴定治疗作用所需的关键免疫细胞来建立AIRISE-02的机制，并在另一种临床相关的黑色素瘤模型中确认疗效。在目标2中，我们将与CMO合作生产符合GMP的AIRISE-02（siSTAT 3，CpG和NP），灭菌，灌装和稳定性研究。在目标3中，我们将与Charles River Toxicology合作，在小鼠和食蟹猴中进行符合GLP的AIRISE-02毒理学研究。将确定最大耐受剂量和毒代动力学特征。将通过监测体重、一般健康状况、注射部位反应、血液学、血清化学/细胞因子和关键器官的组织病理学来评估重复给药后的潜在毒性。在目标4中，我们将与RTI International和奈特癌症研究所的实验治疗中心合作，提交IND申请，以便在2023年初进行I期临床试验。新奇和影响。用于原位癌症疫苗接种的siRNA和佐剂的纳米颗粒共递送以前从未进行过。成功的AIRISE-02将使许多可注射肿瘤受益（例如，黑色素瘤、乳腺癌、淋巴瘤、头颈部），并转移到任何地方。未来的目标发现可以导致利用其他siRNA的新的AIRISE管道。我们的纳米颗粒已经被广泛评估和大规模合成，并且i.t. AIRISE-02限制了全身毒性，同时促进了AIRISE-02向临床的快速转化。

Significance/Goal. Although immune checkpoint inhibitors (ICIs) have shown impressive outcomes in melanoma patients, the majority of patients fail to respond, mainly due to the absence of tumor-infiltrating T cells. In order to boost the anti-tumor T cell repertoire, we have developed a novel immuno-nanotherapeutic, called “Augmenting Immune Response and Inhibiting Suppressive Environment of tumors – AIRISE-02”, based on our patent-pending nanoparticle (NP) co-delivering an immune-activating CpG oligo and siRNA against STAT3. AIRISE-02 relies on “in situ tumor vaccination,” which exploits a locally treated tumor to prime immune response against tumors throughout the body. Unique to AIRISE-02 is the ability to enter both cancer and antigen presenting cells (e.g., DC, macrophage) upon intratumoral (i.t.) injection, resulting in cancer cell death and tumor antigen release, while being safe to and activating the antigen presenting cells. By knocking down STAT3 with siRNA, AIRISE-02 also modulates immunosuppressive environment of the tumor. Given i.t. to only one melanoma tumor, AIRISE-02 caused regression in both treated and untreated distant tumors, demonstrating whole-body immunotherapeutic action. AIRISE-02 was as effective as two ICIs (PD-1 + CTLA- 4, given i.p.) combined, and led to complete cures in 5 out of 8 mice when given with the ICIs. The mice have remained tumor-free for at least 17 months, while mice receiving just ICIs did not survive past 2 months. AIRISE-02 was also effective in colon and breast cancer mouse models and was well tolerated in monkeys. Approach. This direct phase II SBIR focuses on IND-enabling studies of AIRISE-02. In Aim 1, we will establish the mechanism of AIRISE-02 by identifying key immune cells required for therapeutic action and confirm efficacy in another clinically relevant melanoma model. In Aim 2, we will partner with CMOs for manufacturing GMP-compliant AIRISE-02 (siSTAT3, CpG, and NP), sterilization, fill finishes, and stability studies. In Aim 3, we will work with Charles River Toxicology to conduct GLP-compliant toxicology studies of AIRISE-02 in mice and cynomolgus monkeys. The maximum tolerated dose and toxicokinetic profile will be established. Potential toxicity after repeated doses will be assessed by monitoring body weight, general health, injection site reaction, hematology, serum chemistry/cytokines, and histopathology of key organs. In Aim 4, we will partner with RTI International and Knight Cancer Institute’s Center of Experimental Therapeutics to submit an IND application to enable Phase I clinical trial in early 2023. Novelty and Impact. Nanoparticle co-delivery of siRNA and adjuvant for in situ cancer vaccination has never been done before. Successful AIRISE-02 will benefit many injectable tumors (e.g., melanoma, breast, lymphoma, head and neck) with metastasis anywhere. Future target discovery can lead to new AIRISE pipelines utilizing other siRNAs. Our nanoparticle has been extensively evaluated and synthesized at large-scale, and i.t. AIRISE-02 limits systemic toxicity, together facilitating rapid translation of AIRISE-02 to the clinic.