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

摘要 肾癌是美国人口中第8大最常见的癌症，其中透明细胞肾细胞癌 （ccRCC）是最常见的亚型。ccRCC对标准化疗和放疗高度难治， 晚期或转移性肿瘤患者的5年生存率仅为14%。ccRCC通常由 通过冯希佩尔林道（VHL）肿瘤抑制因子的失活，导致组成性激活， 缺氧诱导因子HIF-1α和HIF-2α。HIF是ccRCC有希望的治疗靶点，因为 已知它们参与疾病的发病机制，并且它们在正常的灌注良好的组织中缺乏表达。 组织.此外，作为ccRCC的定义特征的脂质的细胞内积累使得 它们独特地易受与铁依赖性脂质过氧化或铁凋亡相关的细胞死亡的影响。通过 Kuda Therapeutics致力于在同品种SBIR I期项目中优化选择性HIF-2α抑制剂 鉴定了一系列新的化合物，包括先导物KD 061，它们可以降低HIF-1α和HIF-2α，并诱导 铁凋亡在体外和体内，通过结合到新的分子靶点，铁硫簇组装2（ISCA 2）。 ISCA 2抑制触发铁饥饿反应，其抑制铁响应元件（IRE）依赖性铁缺乏。 HIF-2α的翻译，并触发铁过载，导致铁中毒性死亡。引人注目的是，pVHL缺陷 ccRCC细胞具有降低的ISCA 2水平，并且与具有ISCA 2抑制的细胞相比，对ISCA 2抑制更敏感。 pVHL重建，提示选择性靶向pVHL缺陷型ccRCC细胞的治疗窗口 对正常的pVHL活性组织的毒性最小。在小鼠中，KD 061处理介导显著>60%的 通过口服施用RENCA抑制同基因异种移植肿瘤生长而没有可检测的毒性 在治疗剂量下，验证了这种治疗ccRCC的新方法。本SBIR的目标 II期项目是进一步表征Kuda的双重HIF-α抑制剂和铁凋亡的有效性和安全性 诱导电极导线KD 061。这项工作将推动其向研究性新药（IND）申报的发展， 用于ccRCC患者初始治疗的首次人体研究。我们的首要目标是优化KD 061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 研究以确定KD 061在体内口服给药的最佳形式，然后放大合成以获得疗效， 毒理学研究。我们的第二个目标是表征KD 061作为单一药物的体内抗肿瘤功效 在ccRCC的多种小鼠模型中，以及与舒尼替尼或PD-1免疫检查点抑制剂组合， RENCA同基因肾癌模型。我们的第三个目的是确定KD 061在啮齿动物中的体内毒理学 通过进行行业标准非GLP和GLP研究确定起始剂量， 和人类临床试验的剂量限制毒性的来源。在第二阶段完成时，我们将制作 优化KD 061原料药，并表征其有效性和安全性，显著推进KD 061向 IND申请和首次人体试验可以开始改变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.