Preclinical Development of a Novel eNAMPT-Neutralizing mAb for Pulmonary Hypertension

摘要 肺动脉高压(PAH)是一种致命的疾病(没有根治方法)，受到严重影响。 通过失调的炎症途径。此A1 R42 Fast Track STTR应用程序侧重于eNAMPT(额外- 细胞烟酰胺磷酸核糖转移酶)作为一种新的、极具吸引力的多环芳烃靶标。阿奎隆治疗公司 已经开发出一种人源化的eNAMPT中和单抗ALT-100，以解决未满足的治疗需求 改善右室(RV)功能障碍/衰竭和PAH存活率。流传的eNAMPT是一种损害-关联- 激活天然免疫驱动的炎症途径的分子模式蛋白(DAMP) 通过连接Toll样受体4(TLR4)。我们已发布/未发布的数据有力地支持了 ENAMPT在人类PH病理生物学中的作用。首先，我们已经报道了NAMPT的RNA和蛋白质表达 PAH患者PBMCs和重塑的肺血管分泌显著增加。 PAH相关刺激，包括生长因子和缺氧通过HIF-2α信号通路高度上调的过程。 第二，PAH患者血浆eNAMPT水平升高，并与右室功能障碍相关。第三， NAMPT多态(SNPs)以前与炎症严重程度有关，包括ARDS死亡率，现在也是如此。 与PAH严重程度相关，包括大型PAH患者右室功能障碍的心导管指数。最后， 我们已经令人信服地证明了eNAMPT是一个高度可下药的目标，eNAMPT-中和 MAb、ALT-100对临床前PAH血管重构和RV指标的影响 心力衰竭。支持ALT-100作为PAH治疗的可行性，我们已经完成了非IND使能 药代动力学(PK)研究表明，静脉注射ALT-100单抗的半衰期为12-14天 对大鼠的28天毒性研究表明，高达50 mg/kg的ALT-100没有明显的毒性。 我们已经完成了稳定的细胞系开发，产生了研究细胞库和主细胞库，并 完成了200L GMP生物反应器的运行(表达式6 gms/L)；滴度保证了非常低的商品和市场成本 以较低的价格进入市场。ALT-100‘S对急性呼吸窘迫综合征适应证的急性期研究将完成 到2021年11月，再次促进FDA IND对PAH的成功申请。第一阶段的设计目的是 优化ALT-100单抗的给药途径(SubQ与IM)和剂量，进一步验证ALT-100的有效性 在两种临床前PAH大鼠模型(野百合碱、缺氧/SUGEN)中的策略(SA#1)。我们将提供证明- 概念基因组数据验证ALT-100靶向eNAMPT/TLR4途径在大鼠肺组织和PBMC中的作用 作为ALT-100显著阻止PAH进展并可能逆转其严重性的机制 PAH(SA#2)。在大鼠和小型猪身上进行的第二阶段研究将表征PK和药效学 (Pd)ALT-100单抗的特性(SA#3)和ALT-100毒代动力学特性(SA#4)。成功 完成这些I/II阶段STTR研究将能够提交FDA IND申请，其批准 将允许快速进行多环芳烃临床试验，以解决多环芳烃中未得到满足的重大需求。

ABSTRACT Pulmonary arterial hypertension (PAH) is a fatal disease (without curative therapies) that is critically influenced by dysregulated inflammatory pathways. This A1 R42 Fast Track STTR application focuses on eNAMPT (extra- cellular nicotinamide phosphoribosyltransferase) as a novel, highly attractive PAH target. Aqualung Therapeutics has developed a humanized eNAMPT-neutralizing mAb, ALT-100, to address the unmet need for therapies that improve right ventricular (RV) dysfunction/failure and PAH survival. Circulating eNAMPT is a damage-associ- ated molecular pattern protein (DAMP) that robustly activates innate immunity-driven inflammatory pathways via ligation of the Toll-like receptor 4 (TLR4). Our published/unpublished data strongly support involvement of eNAMPT in the pathobiology of human PH. First, we have reported that NAMPT RNA and protein expression and secretion are significantly increased in PBMCs and in remodeled lung vessels from PAH patients with these processes highly upregulated by PAH-relevant stimuli, including growth factors and hypoxia via HIF-2α signaling. Second, plasma eNAMPT levels are elevated and correlate with RV dysfunction in PAH subjects. Thirdly, NAMPT polymorphisms (SNPs), previously linked to inflammatory severity including ARDS mortality, are asso- ciated with PAH severity, including cardiac catherization indices of RV dysfunction in a large PAH GWAS. Lastly, we have compellingly demonstrated that eNAMPT is a highly druggable target, with the eNAMPT-neutralizing mAb, ALT-100, profoundly attenuating and reversing preclinical PAH vascular remodeling and indices of RV heart failure. Supporting the feasibility of ALT-100 as a PAH therapy, we have completed non-IND-enabling pharmacokinetic (PK) studies demonstrating that IV-delivered ALT-100 mAb exhibits a T1/2 half-life of 12-14 days and 28-day toxicity studies in rats demonstrated that up to 50 mg/kg of ALT-100 is without discernable toxicity. We have completed stable cell line development, generated both Research and Master Cell Banks, and have completed a 200L GMP Bioreactor run (expression 6 gms/L); a titer assuring very low Cost of Goods and market entry at a low price point. ALT-100’s acute IND-enabling studies for the indication of ARDS will to be completed by November 2021, again facilitating a successful FDA IND application for PAH. STTR PHASE I is designed to optimize route of delivery (SubQ vs IM) and dosing of ALT-100 mAb and further validate ALT-100 as an effective strategy in two preclinical PAH rat models (monocrotaline, hypoxia/Sugen) (SA #1). We will provide proof-of- concept genomic data validating ALT-100 targeting of the eNAMPT/TLR4 pathway in rat lung tissues and PBMCs as the mechanism by which ALT-100 significantly halts PAH progression and potentially reverses the severity of PAH (SA #2). PHASE II studies conducted in rats and minipigs will characterize the PK and pharmacodynamic (PD) characteristics of the ALT-100 mAb (SA #3) and ALT-100 toxicokinetic properties (SA #4). Successful completion of these PHASE I/ II STTR studies will enable submission of an FDA IND application whose approval will allow rapid movement to conducting PAH clinical trials that address the significant unmet need in PAH.