Development of a novel dual HIF-α inhibitor and inducer of ferroptosis for kidney cancer

摘要 肾癌是美国人第八种最常见的癌症，其中肾透明细胞癌 (CcRCC)是最常见的亚型。CcRCC对标准化疗和放疗高度耐药， 晚期或转移性肿瘤患者的5年存活率仅为14%。CcRCC通常启动 通过灭活冯·希佩尔·林道(VHL)肿瘤抑制因子，导致结构性激活 低氧诱导因子HIF-1α和HIF-2α。HIF是治疗慢性肾细胞癌的有前景的靶点，因为 已知它们参与了疾病的发病机制，并且它们在正常组织中缺乏良好的表达 组织。此外，细胞内脂质的积累，这是ccRCC的一个定义特征，使 它们特别容易受到铁依赖的脂质过氧化或铁下垂相关的细胞死亡的影响。穿过 库达治疗公司在预测性α第一阶段项目中优化选择性缺氧诱导因子-2SBIR抑制剂的努力 发现了一系列新的化合物，包括先导KD061，它们可以降低HIF-1α和HIF-2α，并诱导 通过与新的分子靶点铁硫簇组件2(ISCA2)结合，在体外和体内发生铁下垂。 ISCA2抑制触发铁饥饿反应，从而抑制铁反应元件(IRE)依赖 HIF-2α的翻译，并触发铁超载，导致铁链死亡。引人注目的是，pVHL缺乏 CcRCC细胞ISCA2水平降低，对ISCA2抑制更敏感 PVHL重建，提示选择性靶向pVHL缺陷的ccRCC细胞的治疗窗口 对正常、精通pVHL的组织毒性最小。在小鼠中，KD061治疗缓解了显著&gt；60% 口服给药对Renca同种异种移植瘤生长的抑制作用 在治疗剂量下，验证这种治疗慢性肾细胞癌的新方法。这项SBIR的目标是 第二阶段的项目是进一步表征库达的双重HIF-α抑制剂和铁下垂的有效性和安全性 诱导器引线KD061。这项工作将推动其向研究性新药(IND)备案和 首次对慢性肾细胞癌患者进行初步治疗的人体研究。我们的首要目标是优化KD061药物 物质、配方和合成。在这里，我们将进行盐筛选、多晶型筛选和配方 研究确定KD061在体内的最佳口服形式，然后扩大合成的有效性和 毒理学研究。我们的第二个目标是表征KD061作为单一药物的体内抗肿瘤效果 在多种ccRCC小鼠模型中，并联合应用舒尼替尼或PD-1免疫检查点抑制 伦卡同基因肾癌模型。我们的第三个目标是确定KD061在啮齿动物体内的毒理学 和非啮齿动物物种通过执行行业标准的非GLP和GLP研究来确定起始剂量 以及人体临床试验的剂量限制毒性来源。在第二阶段完成时，我们将生产出 优化的KD061药材，并对其有效性和安全性进行了表征，使KD061向 IND申报和第一次人体试验，在这些试验中，它可以开始改变ccRCC患者的生活。

Abstract Kidney cancer is the 8th most common cancer in the US population, of which clear cell renal cell carcinoma (ccRCC) is the most common subtype. ccRCC is highly refractory to standard chemotherapy and radiation, and patients with advanced or metastatic tumors have a 5-year survival rate of just 14%. ccRCC is typically initiated by inactivation of the von Hippel Lindau (VHL) tumor suppressor, which results in the constitutive activation of the hypoxia inducible factors, HIF-1α and HIF-2α. The HIFs are promising therapeutic targets for ccRCC due to their known involvement in the pathogenesis of the disease, and their lack of expression in normal well-perfused tissue. Additionally, the intracellular accumulation of lipids, which is a defining characteristic of ccRCC, renders them uniquely susceptible to cell death associated with iron-dependent lipid peroxidation or ferroptosis. Through efforts to optimize selective HIF-2α inhibitors in the predicate SBIR Phase I project, Kuda Therapeutics has identified a series of novel compounds, including lead KD061, that decrease both HIF-1α and HIF-2α, and induce ferroptosis in vitro and in vivo, by binding to the novel molecular target, Iron Sulfur Cluster Assembly 2 (ISCA2). ISCA2 inhibition triggers the iron starvation response, which inhibits iron-responsive element (IRE)-dependent translation of HIF-2α, and triggers iron overload, which results in ferroptotic death. Strikingly, pVHL-deficient ccRCC cells have decreased ISCA2 levels and are more sensitive to ISCA2 inhibition compared to cells with pVHL reconstitution, suggesting a therapeutic window for the selective targeting of pVHL-deficient ccRCC cells with minimal toxicity to normal, pVHL-proficient tissue. In mice, KD061 treatment mediates significant >60% inhibition of RENCA syngeneic xenograft tumor growth through oral administration with no detectable toxicities at the therapeutic dose, validating this novel approach for the treatment of ccRCC. The objective of this SBIR Phase II project is to further characterize the efficacy and safety of Kuda’s dual HIF-α inhibitor and ferroptosis inducer lead KD061. This work will advance its development towards Investigational New Drug (IND) filing and first-in-human studies for the initial treatment of patients with ccRCC. Our first aim is to optimize KD061 drug substance, formulation and synthesis. Here we will perform salt screening, polymorph screening and formulation studies to identify the optimal form of KD061 for oral delivery in vivo, then scale-up synthesis for efficacy and toxicology studies. Our second aim is to characterize the in vivo anti-tumor efficacy of KD061 as a single agent in multiple mouse models of ccRCC, and in combination with sunitinib or PD-1 immune checkpoint inhibition in the RENCA syngeneic kidney cancer model. Our third aim is to determine in vivo toxicology of KD061 in a rodent and non-rodent species by performing industry standard non-GLP and GLP studies to identify the starting doses and sources of dose limiting toxicities for human clinical trials. At Phase II completion, we will have produced the optimal KD061 drug substance, and characterized its efficacy and safety, significantly advancing KD061 towards IND filing and first-in-human trials where it can begin to make a difference in the lives of patients with ccRCC.