Novel Enediyne-Based Antibody-Drug Conjugates for Cancers

FDA批准的两种抗体-药物结合物(ADC)(Adcetris®和Kadcyla®)和几乎所有ADC 临床试验是通过将药物随机结合到抗体中的赖氨酸或半胱氨酸残基来准备的， 提供了不同种类的ADC混合物。定点结合是最近对ADC的一项重大改进 开发，产生均匀的ADC，极大地提高了治疗指数。在60个ADC中 目前在临床开发中，近50种药物使用奥司他丁和美坦辛，这两种有效载荷用于 Adcetris®或Kadcyla®，其余使用仅有的五种其他药物中的一种。ADC字段处于关键状态 需要新的、高效的、快速起作用的细胞毒有效载荷，这些有效载荷在许多肿瘤类型中都是有效的。我们 在这项申请中，建议开发新的基于烯二炔的部位特异性ADC用于癌症治疗。具体来说， 我们将重点介绍替安西菌素(TnM)，它是我们最近发现的烯二炔家族的新成员。 天然产品。我们的假设是：(I)TMM是优秀的ADC有效载荷候选者，因为他们 精致的效力和有效的作用模式，(2)对TNM生物合成的遗传操作提供 生产最有前途的TNM类似物以开发接头化学和 促进位点特异性结合，(Iii)TnM与工程硫代单抗的位点特异性结合 硒单抗将产生具有确定的药物与抗体比率(DAR)的同质ADC，以及(Iv) HER2和ROR1的互补靶向将有助于评估新的基于烯二炔的ADC 目前的基准和改善乳腺癌患者的治疗结果。这方面的具体目标 主要内容有：(1)链霉菌TnM生物合成的调控。CB03234将生产出最有前途的 (Ii)抗HER2和抗ROR1硫代单抗的生产和纯化 含2个工程半胱氨酸(Cys)和2个或1个工程硒半胱氨酸(SEC)残基的硒单抗， 分别，(Iii)发展了用于位点特异性连接和传递一组反式 HER2和抗ROR1硫单抗-TnM和Seenomab-TnM结合物，以及(Iv)选择性和 抗HER2和抗ROR1的硫代单抗-TNM和硒单抗-TNM结合物对HER2和HER2的抑制作用 HER2−/ROR1体内外乳腺癌模型的研究这项申请的结果包括：(I) 对ADDC的基本贡献和(Ii)一组抗HER2和抗ROR1的硫代单抗-TNM和硒单抗- TNM作为下一代ADC癌症疗法的结合物。我们研究的长期目标是 发现新的微生物天然产物并利用其精致的细胞毒性作为ADC有效载荷 抗癌药物的发现。

Both the two FDA-approved antibody-drug conjugates (ADCs) (Adcetris® and Kadcyla®) and nearly all ADCs in clinical trials are prepared by randomly conjugating drugs to lysine or cysteine residues in the antibody, affording a heterogeneous ADC mixture. Site-specific conjugation is a major recent improvement to ADC development, yielding homogeneous ADCs with greatly improved therapeutic index. Among the 60+ ADCs currently in clinical development, nearly 50 of them use auristatin and maytansine, the two payloads used in Adcetris® or Kadcyla®, respectively, with the rest using one of only five other drugs. The ADC field is in critical need of new, highly potent, and rapidly acting cytotoxic payloads that are active in many tumor types. We propose in this application to develop new enediyne-based site-specific ADCs for cancer therapy. Specifically, we will focus on tiancimycins (TNMs), which we recently discovered as novel members of the enediyne family of natural products. Our hypotheses are: (i) TNMs are outstanding ADC payload candidates owing to their exquisite potency and validated mode of action, (ii) genetic manipulation of TNM biosynthesis provides outstanding opportunities to produce the most promising TNM analogues to develop the linker chemistry and facilitate site-specific conjugation, (iii) site-specific conjugation of TNMs to engineered thiomabs and selenomabs will generate homogeneous ADCs with defined drug-to-antibody ratios (DARs), and (iv) complementary targeting of HER2 and ROR1 will help evaluate the novel enediyne-based ADCs against current benchmarks and improve therapeutic outcomes for breast cancer patients. The specific aims for this grant are: (i) manipulation of TNM biosynthesis in Streptomyces sp. CB03234 to produce the most promising TNMs for site-specific conjugation, (ii) production and purification of anti-HER2 and anti-ROR1 thiomabs and selenomabs with 2 engineered cysteine (Cys) and 2 or 1 engineered selenocysteine (Sec) residues, respectively, (iii) development of linker chemistry for site-specific conjugation and delivery of a panel of anti- HER2 and anti-ROR1 thiomab-TNM and selenomab-TNM conjugates, and (iv) evaluation of selectivity and potency of the anti-HER2 and anti-ROR1 thiomab-TNM and selenomab-TNM conjugates against HER2+ and HER2−/ROR1+ breast cancers in both in vitro and in vivo models. The outcomes of this application include (i) fundamental contributions to ADCs and (ii) a panel of anti-HER2 and anti-ROR1 thiomab-TNM and selenomab- TNM conjugates as next-generation ADC therapeutics for cancers. The long-term goal of our research is to discover novel microbial natural products and harness their exquisite cytotoxicity as ADC payloads for anticancer drug discovery.