CMG1A46

作者：钟东英 薛超然 美工：何国红 罗真真 排版：马超 01 引言 在生物药研发的浪潮中，单克隆抗体（mAb）作为核心力量，已充分展示出巨大的临床价值和商业潜力。然而，面对尚未满足的医疗需求和日趋复杂的疾病机制，开发下一代治疗性生物大分子已成为行业共识。三优生物精准把握这一趋势，依托“智能超万亿分子发现平台”，成功构建了新型靶向蛋白库。新型靶向蛋白凭借其小巧的分子结构、优异的组织穿透力及卓越的稳定性，有效突破了传统抗体在物理特性上的局限。它不仅能够高效靶向常规抗体难以触及的靶点，还为吸入式给药、跨越血脑屏障等创新治疗策略提供了可能，从而为癌症、自身免疫疾病和呼吸系统疾病等治疗领域开辟了全新的前景。 02 文库背景 全球生物大分子药物市场已达数千亿美元，并以每年约10%的速度持续快速增长，其中抗体类药物贡献了超过一半的市场份额。然而，面对尚未满足的医疗需求和日益复杂的疾病机制，行业正在积极寻求新的分子形式。Anticalin作为一种独特的人源化非抗体类蛋白质，凭借其小巧的分子量（约20 kDa）、卓越的组织穿透能力和出色的稳定性，有效克服了传统IgG抗体（约150 kDa）分子量大、组织渗透性差的局限性。它不仅能够以更高的亲和力结合传统抗体难以触及的靶点，还可实现吸入式给药等创新方式，为癌症、自身免疫疾病及呼吸系统疾病开辟了新的治疗途径。与另一类小分子抗体-纳米抗体相比，Anticalin源自人源蛋白，免疫原性更低，其独特结构使其能结合更广泛的靶点类型，包括某些小分子和难以触及的凹陷位点。 尽管目前中国市场上尚未有新型靶向蛋白药物获批，全球范围内该类药物的开发也多处于早期临床开发阶段，但其在特定疾病领域的巨大潜力已获得阿斯利康等国际巨头的认可。目前，Anticalin药物开发的关键挑战之一在于文库构建，核心在于如何获得高质量、高多样性的文库，从而确保筛选出兼具高亲和力与高稳定性的目标分子。为解决这一核心痛点，三优生物依托其深厚的技术积累和创新能力，成功推出新型靶向蛋白发现系统解决方案。采用独特的高通量自动化筛选技术，从库容高达百亿级的Anticalin文库中快速识别出具有高亲和力与高特异性的候选分子。该系统不仅是三优生物“智能超万亿分子发现平台”的重要组成部分，更标志着三优生物在下一代生物大分子药物开发领域的战略性布局和突破。 03 文库构建 三优生物构建的新型靶向蛋白库采用人血清高丰度天然脂质运载蛋白作为核心骨架。与异源蛋白相比，这种人源天然骨架理论上具有更低的免疫原性，可显著降低药物进入人体后引发免疫排斥反应的风险。在构建过程中，首先通过对已解析的抗原-Anticalin复合物结构进行深入分析，精确识别出Anticalin骨架上与抗原靶标直接相互作用的四个关键结合区域（binding regions）。基于这一结构分析，有针对性地在这些核心结合区域引入了更多的氨基酸结合位点，从而大幅度增加与靶标结合的可能性，显著提升结合亲和力。随后，通过对文库进行精细的翻译后修饰（PTM）优化，进一步改善其生物学活性、稳定性和药代动力学特性。此外，通过精确调控等电点（pI），有效调控分子的溶解度和在体内的分布，使其在特定生理环境下表现出更优异的性能，避免多反应性的产生。 最终，通过这一整套严谨而高效的设计体系，并采用国际领先的引物技术，成功构建了总库容高达6.0×10^10的分子发现引擎。该文库不仅在库容上远超传统文库，更在分子质量与多样性方面实现了显著提升。三优生物的智能新型靶向蛋白库，为引领下一代生物大分子药物开发奠定了坚实基础，并将为众多难治性疾病的治疗带来革命性希望。 ▼ Table 1 Basic information of anticalin library 04 文库特性 01 新型靶向蛋白稳定性更好 三优生物通过PTM位点改造，对影响分子稳定性的糖基化位点、游离半胱氨酸位点以及其他关键氨基酸位点进行突变（如图Fig. 1所示），从而增强分子的稳定性。随后，通过等电点优化，有效降低了分子表面电荷聚集，减少新型靶向蛋白的多反应性风险，进一步提高了分子靶向特异性。 ▲ Fig. 1 a. Modification of glycosylation sites, b. Modification of other PTMs, c. Modification of isoelectric point 02 文库全面质控分析 三优生物完成新型靶向蛋白库的构建后，对其进行了全面的文库质量检测。测序结果显示，文库中有效分子占比大于70%，氨基酸分布与设计预期高度一致。如图Fig. 2所示，针对单一位点，图中并列展示了理论设计占比与实际测序占比，结果显示，实际数值与理论设计基本吻合。 ▲ Fig. 2 The percentage distribution of amino acids in each variable region 03 全面成药性分析 在构建百亿级新型靶向蛋白库的过程中，通过规避PTM位点，显著提高了分子的稳定性。通过高通量自动化筛选服务获得的候选分子，可在真核表达后进行全面的成药性分析。如Table. 1所示，成药性分析涵盖多个维度，包括纯度及浓度测定、一级结构分析和亲和力及亲和动力学等多个维度。 ▼ Table 1 Drug developability of molecule from AI-SYAC 05 代表案例 01 抗IL-4Rα新型靶向蛋白发现 基本信息：IL-4Rα（白细胞介素4受体α亚基）为I型细胞因子受体，是IL-4与IL-13信号传导的核心共受体。其通过激活JAK-STAT通路（尤以STAT6磷酸化为核心）驱动Th2型免疫反应，在特应性皮炎、哮喘、慢性鼻窦炎等2型炎症性疾病中起核心病理作用。该靶点在炎症部位上皮细胞、B细胞及嗜酸性粒细胞表面高表达。 竞争格局：全球仅度普利尤单抗（Dupilumab）一款抗IL-4Rα抗体药物上市（2023年销售额破117亿美元）。在研管线集中于生物类似药（如博锐生物BR110已报产）及改良型分子（如康诺亚CM310、康乃德CBP-201进入III期），尚无非抗体类靶向蛋白药物获批。 药物MOA：新型靶向蛋白特异性结合IL-4Rα的细胞因子结合域，竞争性阻断IL-4/IL-13受体复合物组装，抑制下游JAK-STAT信号通路活化，从而抑制Th2炎症反应及组织纤维化进程，逆转2型免疫病理损伤。 02 抗IL-4Rα新型靶向蛋白关键结果 如Fig. 3-4所示，新型靶向蛋白候选分子在真核水平上进行ELISA结合实验、BLI亲和动力学检测。Fig. 3展示了ELISA水平上候选分子与IL-4Rα抗原蛋白结合活性，其EC50可以达到0.038 μg/mL，候选分子亲和力与Bench marker（dupilumab）相当。Fig. 4显示候选分子A001的KD为2.47E-09 M、ka为1.94E+05 M-1s-1、kd为4.78E-04 s-1，分子亲和力达到纳摩尔水平。 ▲ Fig. 3. The binding activity of ELISA ▲ Fig. 4. The kinetics of BLI 06 总结展望 在生物药研发的创新前沿，三优生物依托“智能超万亿分子发现平台”，凭借其独特的新型靶向蛋白发现系统解决方案，为下一代大分子药物的开发开启了新纪元。该系统以Anticalin文库为核心，成功突破了传统抗体药物的局限性，尤其是在小分子尺寸、卓越的组织穿透能力及优异的稳定性方面展现出显著优势，为吸入式给药与跨越血脑屏障等创新治疗途径提供了坚实支撑。 展望未来，尽管新型靶向蛋白药物在中国乃至全球市场仍处于早期发展阶段，但其独特的技术优势已获得国际制药巨头的认可。三优生物凭借这一创新平台，不仅有效解决了行业内文库构建的关键瓶颈，更为快速发掘高品质与高成药性潜力的新型靶向蛋白药物奠定了坚实基础。此举标志着三优生物已在生物大分子药物开发领域完成前瞻性战略布局，未来有望为癌症、自身免疫疾病等多种难治性疾病的治疗带来突破性进展。 Sanyou 10th Anniversary: AI-STAL-Anticalin Novel Targeted Protein Library 01 Introduction In the dynamic landscape of biopharmaceutical development, monoclonal antibodies (mAbs) have long been the cornerstone, demonstrating immense clinical value and commercial potential. However, to address unmet medical needs and increasingly complex disease mechanisms, the industry is focused on developing next-generation therapeutic biomolecules. SanyouBio has embraced this trend, leveraging its "Artificial Intelligence Super-Trillion Molecular Discovery Platform" to successfully construct a novel targeted protein library. These novel proteins, characterized by their small size, superior tissue penetration, and exceptional stability, overcome the physical limitations of traditional antibodies. They can effectively target sites inaccessible to conventional antibodies and enable innovative delivery strategies, such as inhalation and blood-brain barrier penetration. This innovation opens new avenues for treating conditions like cancer, autoimmune diseases, and respiratory illnesses. 02 Library Background The global market for biologic drugs is valued at hundreds of billions of dollars and is experiencing rapid, sustained growth of approximately 10% annually. Antibodies account for more than half of this market. Yet, persistent unmet medical needs and complex disease mechanisms are driving the search for new molecular formats. Anticalins, a unique class of human-derived non-antibody proteins, offer a compelling solution. Their small molecular weight (approx. 20 kDa), excellent tissue penetration, and high stability overcome the limitations of large traditional IgG antibodies (approx. 150 kDa), which have poor tissue permeability. Anticalins can bind to targets with higher affinity, including those difficult for conventional antibodies to reach, and enable novel delivery methods like inhalation. Compared to another class of small antibodies, nanobodies, Anticalins are derived from human proteins, leading to lower immunogenicity. Their unique structure allows them to bind to a wider range of targets, including certain small molecules and cryptic binding pockets. While no novel targeted protein drugs have been approved in China yet and most global developments are in early clinical stages, their immense potential in specific disease areas has been recognized by major international companies like AstraZeneca. A key challenge in Anticalin drug development is library construction-specifically, obtaining a high-quality, diverse library to ensure the successful screening of molecules with high affinity and stability. To solve this critical problem, SanyouBio has leveraged its deep technical expertise to launch a novel targeted protein discovery system. This system uses unique high-throughput automated screening technology to rapidly identify candidate molecules with high affinity and specificity from a massive Anticalin library containing tens of billions of variants. This system is a vital component of SanyouBio's "Artificial Intelligence Super-Trillion Molecular Discovery Platform " and marks a strategic breakthrough in the development of next-generation biologic drugs. 03 Library Construction The novel targeted protein library built by SanyouBio utilizes a human serum highly abundant natural lipocalin as its core scaffold. Compared to foreign proteins, this human-derived scaffold theoretically has lower immunogenicity, significantly reducing the risk of immune rejection after administration. During construction, a thorough structural analysis of known antigen-Anticalin complexes was performed to precisely identify the four key binding regions on the Anticalin scaffold that directly interact with the antigen target. Based on this structural data, additional amino acid binding sites were strategically introduced into these core regions. This significantly increased the likelihood of target binding and boosted binding affinity. The library then underwent fine-tuned post-translational modifications (PTMs) to further improve biological activity, stability, and pharmacokinetic properties. Furthermore, precise modulation of the isoelectric point (pI) was used to control molecular solubility and in vivo distribution, optimizing performance in specific physiological environments and preventing multi-reactivity. This rigorous and efficient design, combined with leading primer technology, resulted in a molecular discovery engine with a massive total capacity of 6.0×10^10. This library not only surpasses traditional libraries in size but also represents a significant leap forward in molecular quality and diversity. SanyouBio's smart novel targeted protein library establishes a solid foundation for leading the development of next-generation biopharmaceuticals, offering revolutionary hope for the treatment of numerous intractable diseases. ▼ Table 1 Basic information of anticalin library 04 Library Characteristics 01 Enhanced Stability of Novel Targeted Proteins SanyouBio has improved molecular stability by modifying post-translational modification (PTM) sites, mutating key amino acids, and altering glycosylation and free cysteine sites (as shown in Fig. 1). Additionally, isoelectric point optimization effectively reduces the accumulation of surface charges, mitigating the risk of multi-reactivity and further enhancing the protein's targeting specificity. ▲ Fig. 1 a. Modification of glycosylation sites, b. Modification of other PTMs, c. Modification of isoelectric point 02 Comprehensive Library Quality Control Analysis After constructing the novel targeted protein library, SanyouBio performed a thorough quality assessment. Sequencing results showed that over 70% of the molecules in the library were effective, and the amino acid distribution was highly consistent with the original design. As depicted in Fig. 2, which compares the theoretical and actual proportions for a single site, the real-world data closely aligns with the design expectations. ▲ Fig. 2 The percentage distribution of amino acids in each variable region 03 Comprehensive Developability Analysis During the construction of the tens-of-billions-scale novel targeted protein library, the team improved stability by designing around PTM sites. Candidate molecules identified through high-throughput automated screening can undergo comprehensive developability analysis after eukaryotic expression. As detailed in Table 1, this analysis includes multiple parameters such as purity, concentration, primary structure analysis, and affinity and kinetic studies. ▼ Table 1 Drug developability of molecule from AI-SYAC 05 Case Studies 01 Discovery of a Novel Anti-IL-4Rα Targeted Protein Basic Information: IL-4Rα (interleukin-4 receptor alpha subunit) is a type I cytokine receptor and a core co-receptor for IL-4 and IL-13 signal transduction. It drives Th2 immune responses by activating the JAK-STAT pathway (primarily through STAT6 phosphorylation). It plays a crucial role in type 2 inflammatory diseases such as atopic dermatitis, asthma, and chronic rhinosinusitis. This target is highly expressed on epithelial cells, B cells, and eosinophils at inflammatory sites. Competitive Landscape: Globally, only one anti-IL-4Rα antibody drug, Dupilumab (with 2023 sales exceeding $11.7 billion), has been approved. The current pipeline is concentrated on biosimilars (e.g., Boan Biotech's BR110, which has been submitted for approval) and next-generation molecules (e.g., Conroy's CM310 and Connect's CBP-201, both in Phase III). No non-antibody targeted protein drugs have been approved for this target. Mechanism of Action (MOA): The novel targeted protein specifically binds to the cytokine-binding domain of IL-4Rα, competitively blocking the assembly of the IL-4/IL-13 receptor complex. This inhibits the activation of the downstream JAK-STAT signaling pathway, thereby suppressing the Th2 inflammatory response and the process of tissue fibrosis, and reversing type 2 immune pathological damage. 02 Key Results for the Anti-IL-4Rα Novel Targeted Protein As shown in Fig. 3-4, the novel targeted protein candidate molecule underwent ELISA and BLI kinetic analysis at the eukaryotic level. Fig. 3 demonstrates the candidate's binding activity to the IL-4Rα antigen protein at the ELISA level, achieving an EC50 of 0.038μg/mL. The affinity is comparable to that of the benchmark, Dupilumab. Fig. 4 shows that candidate molecule A001 has a KD of 2.47E-09 M, indicating nanomolar affinity level. ▲ Fig. 3. The binding activity of ELISA ▲ Fig. 4. The kinetics of BLI 06 Summary and Outlook At the forefront of biopharmaceutical innovation, SanyouBio, with its "Artificial Intelligence Super-Trillion Molecular Discovery Platform" and unique novel targeted protein discovery system, is pioneering a new era in the development of next-generation biologics. This system, centered on the Anticalin library, successfully overcomes the limitations of traditional antibody drugs, offering significant advantages in small size, excellent tissue penetration, and superior stability. It provides robust support for innovative therapeutic approaches like inhaled administration and blood-brain barrier penetration. Looking ahead, while novel targeted protein drugs are still in early development in both China and the global market, their unique technical advantages have already garnered recognition from international pharmaceutical giants. SanyouBio's innovative platform not only addresses critical industry bottlenecks in library construction but also lays a solid foundation for the rapid discovery of high-quality, highly drugable novel targeted proteins. This marks a forward-looking strategic move in the biopharmaceutical field, with the potential to bring about breakthrough advancements in the treatment of various intractable diseases, including cancer and autoimmune disorders. 推荐阅读 三优十周年｜靶点篇-自身免疫疾病靶点介绍 创新前沿｜三优生物类器官产学研联盟启航 中和抗体“硬核出击”，斩断CHIKV病毒感染链 三优十周年｜服务篇-靶点至PCC药物研发 三优十周年｜靶点篇-六大恶性肿瘤靶点介绍创新前沿｜2025ADC热门靶点与技术创新启示三优十周年｜AI-STAL篇-高等电点单域抗体库 6类分子形式之环状多肽分子产生系统解决方案 轻松玩转三优oneClick+线上9大云程序 6类分子形式之mRNA分子产生系统解决方案 三重好礼相送暨四种抗体制备解决方案全新上线 三优生物单域抗体产生系统解决方案 三优生物双抗参比品网站SY-BsAb正式上线 三优ADC药物研发系统解决方案 三优生物oneClick+平台再次上新 关于三优生物 三优生物是一家以“让天下没有难做的创新生物药”为使命，以超万亿分子库和智能科技驱动的生物医药高科技企业。 公司致力于打造全球顶尖的原创新药创新工场。公司以智能超万亿分子库（AI-STAL）为核心；以干湿结合、国际领先的创新生物药智能化及一体化研发平台为依托；以多样化的业务模式推动全球创新药物的研发及产业化。 公司总部位于中国上海，在亚洲、北美洲、欧洲等多地建立了业务中心，形成了全球化的业务网络，现有投产及布局的研发及GMP场地20000多平方米。 公司已与全球2000多家药企、生技公司等建立了良好的合作关系，已赋能1200多个新药研发项目；已完成50多个合作研发项目，其中10多个协同研发项目已推至IND及临床研发阶段。 公司已申请130多项发明专利，其中30多项发明专利已获得授权，并获得了国家级高新技术企业、上海市专精特新、ISO9001、ISO27001等10余项资质及体系认证。