Nanoparticle-based targeted codelivery of siRNA and taxane to treat drug-resistant HER2+ breast cancer

该SBIR快速通道应用程序的重点是开发用于共同递送siRNA的纳米结构， 耐药人表皮生长因子受体2型阳性（HER 2+）乳腺癌的化疗药物 癌HER 2+乳腺癌是呈现HER 2过表达的亚型，占乳腺癌的15-25%。 浸润性乳腺癌HER 2+乳腺癌预后差，尽管目前一线治疗非常严格 使用两种HER 2靶向疗法（曲妥珠单抗和帕妥珠单抗）和一种紫杉烷（紫杉醇或紫杉醇）治疗 多西他赛）。该药物组合需要6小时的输液时间，每个疗程的费用超过25万美元， 并且有许多严重的不良事件，而无进展生存期仅为18个月。 为了解决这些缺点，我们寻求开发一种可以取代三种药物的单一疗法。 组合.我们将把紫杉烷纳入我们最近开发的纳米结构，用于靶向递送 针对HER 2的siRNA（siHER 2）。该纳米结构是一种50纳米的中孔二氧化硅纳米颗粒的混合物， （MSNP）和共聚物涂层。它与HER 2抗体缀合用于靶向递送。SiRNA是 最后加载，并在PEG层下完全保护其免受血液酶降解24小时（相对于<30 min作为游离siRNA）。siHER 2-纳米构建体降低>80%的HER 2蛋白水平，并且显示出 克服癌症对曲妥珠单抗和帕妥珠单抗的耐药性，这两种药物仅阻断HER 2活性。它诱导 HER 2+细胞的凋亡，但对培养物中的HER 2-或器官细胞是安全的。纳米结构具有 在小鼠的血液、免疫细胞、一般健康、肾脏和肝脏中具有优异的安全性。溶胶-凝胶MSNP 合成和逐层表面改性提供了高合成再现性和可扩展性。MSNP是 也以其高表面积和硅烷醇化学而闻名，适用于装载疏水性药物如紫杉烷。 在小鼠中，siHER 2-纳米构建体抑制了对曲妥珠单抗耐药的原位肿瘤的生长， 紫杉醇，但不能根除肿瘤。因此，如在一线治疗中，我们结合了低剂量的 紫杉烷转移到siHER 2-纳米构建体的MSNP核心上，这在体外最大化了癌细胞死亡。 在第一阶段（目标1），我们将在紫杉烷和siHER 2负载方面进一步优化我们的纳米构建体， 筛选它们的最佳尺寸、药物释放曲线、在HER 2+癌细胞中的功效以及对正常细胞的安全性。 在II期，将在目标2和目标3中评价优化的纳米构建体的体内功效和PK特征。 目标3中对小鼠血液、免疫细胞、器官功能和整体健康的安全性。原发性原位 将利用肿瘤和转移模型，以上述一线治疗作为基准。 结果将为向FDA提交研究性新药（IND）申请提供重要数据。这 该项目是PDX Pharmaceuticals，LLC，专门从事材料优化， 表征和体外筛选，以及部门。生物医学工程和奈特癌症研究所 OHSU医学院，专门从事癌症生物学和肿瘤模型中的药物评价。

This SBIR Fast-Track application focuses on the development of a nanoconstruct for co-delivery of siRNA and chemotherapy drugs to drug-resistant human epidermal growth factor receptor type 2-positive (HER2+) breast cancer. HER2+ breast cancer is a subtype that presents HER2 overexpression and accounts for 15-25% of invasive breast cancers. HER2+ breast cancer has poor prognosis despite the rigorous current first-line treatment using two HER2-targeted therapies (trastuzumab and pertuzumab) and one taxane (paclitaxel or docetaxel). The drug combination requires 6 hours of infusion time, costs over $250,000 per treatment course, and has many severe adverse events, while achieving a progression-free survival of only 18 months. To address these shortcomings, we seek to develop a single therapy that can replace the three-drug combination. We will incorporate a taxane onto our recently developed nanoconstruct for targeted delivery of siRNA against HER2 (siHER2). The nanoconstruct is a hybrid of a 50-nm mesoporous silica nanoparticle (MSNP) and a co-polymer coating. It is conjugated with HER2 antibodies for targeted delivery. SiRNA is loaded last and was fully protected under PEG layer from blood enzymatic degradation for 24 hours (vs. <30 min as free siRNA). The siHER2-nanoconstruct reduced >80% HER2 protein levels, and was shown to overcome cancer resistance to trastuzumab and pertuzumab, which only block HER2 activity. It induced apoptotic death of HER2+ cells, but was safe to HER2- or organ cells in culture. The nanoconstruct had an excellent safety profile in blood, immune cells, general health, kidney and liver of mice. Sol-gel MSNP synthesis and layer-by-layer surface modification afford high synthesis reproducibility and scalability. MSNP is also known for its high surface area and silanol chemistry, suitable for loading hydrophobic drugs like taxanes. In mice, the siHER2-nanoconstruct inhibited growth of orthotopic tumors resistant to trastuzumab and paclitaxel but did not eradicate the tumors. Thus, as in the first line therapy, we incorporated a low dose of taxane onto MSNP core of the siHER2-nanoconstructs, which maximized cancer cell death in vitro. In Phase I (Aim 1), we will further optimize our nanoconstruct in terms of taxane and siHER2 loading and screen them for optimal size, drug release profile, efficacy in HER2+ cancer cells, and safety to normal cells. In Phase II, the optimized nanoconstruct will be evaluated for in vivo efficacy and PK profile in Aim 2 and the safety to blood, immune cells, organ function and overall health of mice in Aim 3. Both primary orthotopic tumor and metastasis models will be utilized, with the aforementioned first-line therapy as the benchmark. Results will provide important data towards an investigational new drug (IND) application to the FDA. This project is a collaboration between PDX Pharmaceuticals, LLC, specialized in material optimization, characterization, and screening in vitro, and the Dept. of Biomedical Engineering and Knight Cancer Institute of the OHSU School of Medicine, specialized in cancer biology and drug evaluation in tumor models.