Development of Non-Catalytic Peptide Inhibitors of Focal Adhesion Kinase (FAK) for Use in Melanoma

摘要 黑色素瘤是皮肤癌中最致命的一种，估计影响了120万美国人。这种疾病有一个 转移性黑色素瘤预后差，中位生存期为 只有5-8个月。预计2021年黑色素瘤的医疗费用将达到近40亿美元， 发病率尽管近年来作出了相当大的努力， 尽管针对黑色素瘤的免疫疗法，IV期黑色素瘤患者的5年生存率仍保持在 百分之二十因此，对于新的治疗策略以改善以下疾病的结局存在显著的未满足的临床需求： 黑色素瘤患者粘着斑激酶（FAK）是一种非受体酪氨酸激酶和支架蛋白 由于其涉及癌症的多种标志而被认为是非常有前途的癌症药物靶标， 包括迁移、侵袭、转移、凋亡、增殖、血管生成和免疫细胞抑制。 FAK在60-80%的多种实体瘤中过表达，包括乳腺、结肠、卵巢和胰腺肿瘤。 癌症，并且在人黑素瘤样品中大量上调。尽管它有作为治疗靶点的潜力， 迄今为止开发的FAK抑制剂仅针对激酶结构域的ATP结合口袋，并且已经表明 临床上的小成功然而，最近的原理验证研究表明， (FAT)FAK的支架结构域是黑色素瘤存活、生长和转移的重要调节因子。 此外，FAKnostics的初步数据显示，FAT结构域抑制选择性地降低生存能力 NRAS突变的黑色素瘤细胞，黑色素瘤的一个子集，占所有病例的20-30%， 靶向治疗。在这些发现的基础上，FAKnostics已经确定了一个一流的肽系列， 直接靶向FAK的FAT结构域并在NRAS中具有显著抗癌作用的FAK抑制剂- 突变型黑素瘤在第一阶段，FAKnostics确定了一种结合力高约5,000倍的钉合肽候选物 与天然桩蛋白LD 2基序相比，对FAK FAT结构域的亲和力。另外，我们已经证明了- 通过在同基因小鼠模型中确认体内功效来验证该方法的概念。通过第二阶段 项目，FAKnostics寻求继续通过以下具体的治疗方法的发展 目的：1）通过药物化学的迭代优化先导肽，以提高细胞效能和药物- 2）在药代动力学和体内功效研究中评估最佳优化的肽，以选择 临床前候选肽; 3）完成最终临床候选肽的制剂研究并评估 大鼠中的安全性/毒理学;和4）确定适合于使用黑素瘤患者的临床试验的患者群体- 衍生的异种移植物和同基因功效模型并确定最佳组合治疗方案。后 成功完成这些目标，FAKnostics打算启动GMP生产和GLP 为FDA IND申请和临床试验做准备的安全性/毒理学研究。

Abstract Melanoma is the deadliest form of skin cancer, affecting an estimated 1.2 million Americans. The disease has a high propensity for dissemination, and metastatic melanoma has a dismal prognosis, with a median survival of only 5–8 months. Healthcare costs for melanoma in 2021 are projected to reach nearly $4 billion, with a rising incidence rate. Despite considerable efforts in recent years to develop more effective targeted and immunotherapies against melanoma, the 5-year survival rate for stage IV melanoma patients remains around 20%. Thus, there is a significant unmet clinical need for novel treatment strategies to improve outcomes for patients with melanoma. Focal Adhesion Kinase (FAK) is a non-receptor tyrosine kinase and scaffolding protein considered to be a highly promising cancer drug target due to its involvement in multiple hallmarks of cancer, including migration, invasion, metastasis, apoptosis, proliferation, angiogenesis, and immune-cell suppression. FAK is overexpressed in 60–80% of multiple solid tumors, including breast, colon, ovarian, and pancreatic cancer, and is massively upregulated in human melanoma samples. Despite its potential as a therapeutic target, the FAK inhibitors developed to date only target the ATP-binding pocket of the kinase domain and have shown little clinical success. However, recent proof-of-principle studies have shown that the focal adhesion targeting (FAT) scaffolding domain of FAK is an essential regulator of melanoma survival, growth, and metastasis. Additionally, FAKnostics has preliminary data showing that FAT domain inhibition selectively decreases viability of NRAS-mutant melanoma cells, a subset of melanoma that represents 20-30% of all cases and has no effective targeted therapies. On the basis of these findings, FAKnostics has identified a first-in-class series of peptidic FAK inhibitors that directly target the FAT domain of FAK and have significant anti-cancer effects in NRAS- mutant melanoma. In Phase I, FAKnostics identified a stapled peptide candidate with ~5,000-fold higher binding affinity to the FAK FAT domain versus the native paxillin LD2 motif. Furthermore, we have demonstrated proof- of-concept of this approach by confirming in vivo efficacy in a syngeneic mouse model. Through this Phase II project, FAKnostics seeks to continue the development of this treatment approach through the following specific aims: 1) Optimize lead peptides through iterations of medicinal chemistry to improve cellular potency and drug- like properties; 2) Evaluate top optimized peptides in pharmacokinetic and in vivo efficacy studies to select preclinical candidate peptide; 3) Complete formulation studies of final clinical candidate peptide and evaluate safety/toxicology in rats; and 4) Determine patient population suitable for clinical trials using melanoma patient- derived xenograft and syngeneic efficacy modelsand determine optimal combinational treatment regimen. Upon successful completion of these aims, FAKnostics intends to initiate GMP manufacturing and GLP safety/toxicology studies in preparation for an FDA IND application and a clinical trial.