Anna Kopp, Jiakun Guan, Colette Johnston, Steven Vance, James Legg, Laurie Galson-Holt, Greg M Thurber
{"title":"Design of Crosslinking Antibodies For T-Cell Activation: Experimental and Computational Analysis of PD-1/CD137 Bispecific Agents.","authors":"Anna Kopp, Jiakun Guan, Colette Johnston, Steven Vance, James Legg, Laurie Galson-Holt, Greg M Thurber","doi":"10.1208/s12248-024-00937-3","DOIUrl":null,"url":null,"abstract":"<p><p>Bispecific and multispecific agents have become increasingly utilized in cancer treatment and immunotherapy, yet their complex design parameters present a challenge in developing successful therapeutics. Bispecifics that crosslink receptors on two opposing cells can provide specific activation of a receptor only when these cells are in close spatial proximity, such as an immune cell and cancer cell in a tumor. These agents, including T cell activating bispecifics, can avoid off-tumor toxicity through activation only in the tumor microenvironment by utilizing a tumor target to cluster T-cell receptors for a selective costimulatory signal. Here, we investigate a panel of PD-1/CD137 targeted Humabody V<sub>H</sub> domains to determine the key factors for T cell activation, such as affinity, valency, expression level, domain orientation, and epitope location. Target expression is a dominant factor determining both specificity and potency of T cell activation. Given an intrinsic expression level, the affinity can be tuned to modulate the level of activation and IC<sub>50</sub> and achieve specificity between low and high expression levels. Changing the epitope location and linker length showed minor improvements to activation at low expression levels, but increasing the valency for the target decreased activation at all expression levels. By combining non-overlapping epitopes for the target, we achieved higher receptor activation at low expression levels. A kinetic model was able to capture these trends, offering support for the mechanistic interpretation. This work provides a framework to quantify factors for T cell activation by cell-crosslinking bispecific agents and guiding principles for the design of new agents.</p>","PeriodicalId":50934,"journal":{"name":"AAPS Journal","volume":null,"pages":null},"PeriodicalIF":5.0000,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11497593/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"AAPS Journal","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1208/s12248-024-00937-3","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PHARMACOLOGY & PHARMACY","Score":null,"Total":0}
引用次数: 0
Abstract
Bispecific and multispecific agents have become increasingly utilized in cancer treatment and immunotherapy, yet their complex design parameters present a challenge in developing successful therapeutics. Bispecifics that crosslink receptors on two opposing cells can provide specific activation of a receptor only when these cells are in close spatial proximity, such as an immune cell and cancer cell in a tumor. These agents, including T cell activating bispecifics, can avoid off-tumor toxicity through activation only in the tumor microenvironment by utilizing a tumor target to cluster T-cell receptors for a selective costimulatory signal. Here, we investigate a panel of PD-1/CD137 targeted Humabody VH domains to determine the key factors for T cell activation, such as affinity, valency, expression level, domain orientation, and epitope location. Target expression is a dominant factor determining both specificity and potency of T cell activation. Given an intrinsic expression level, the affinity can be tuned to modulate the level of activation and IC50 and achieve specificity between low and high expression levels. Changing the epitope location and linker length showed minor improvements to activation at low expression levels, but increasing the valency for the target decreased activation at all expression levels. By combining non-overlapping epitopes for the target, we achieved higher receptor activation at low expression levels. A kinetic model was able to capture these trends, offering support for the mechanistic interpretation. This work provides a framework to quantify factors for T cell activation by cell-crosslinking bispecific agents and guiding principles for the design of new agents.
双特异性和多特异性制剂在癌症治疗和免疫疗法中的应用越来越广泛,但其复杂的设计参数给成功开发治疗药物带来了挑战。双特异性制剂能交联两个对立细胞上的受体,只有当这些细胞在空间上接近时,如肿瘤中的免疫细胞和癌细胞,才能特异性地激活受体。这些药物,包括激活 T 细胞的双特异性药物,通过利用肿瘤靶点聚集 T 细胞受体以产生选择性成本刺激信号,只在肿瘤微环境中激活,从而避免瘤外毒性。在这里,我们研究了一组 PD-1/CD137 靶向 Humabody VH 结构域,以确定 T 细胞激活的关键因素,如亲和力、效价、表达水平、结构域方向和表位位置。靶点表达是决定 T 细胞激活特异性和效力的主要因素。给定一个内在表达水平,就可以调整亲和力以调节激活水平和 IC50,并在低表达水平和高表达水平之间实现特异性。改变表位位置和连接体长度对低表达水平下的激活有轻微改善,但增加目标的效价会降低所有表达水平下的激活。通过组合目标物的非重叠表位,我们在低表达水平下获得了更高的受体激活率。动力学模型能够捕捉到这些趋势,为机理解释提供了支持。这项工作为量化细胞交联双特异性制剂激活 T 细胞的因素提供了一个框架,也为设计新制剂提供了指导原则。
期刊介绍:
The AAPS Journal, an official journal of the American Association of Pharmaceutical Scientists (AAPS), publishes novel and significant findings in the various areas of pharmaceutical sciences impacting human and veterinary therapeutics, including:
· Drug Design and Discovery
· Pharmaceutical Biotechnology
· Biopharmaceutics, Formulation, and Drug Delivery
· Metabolism and Transport
· Pharmacokinetics, Pharmacodynamics, and Pharmacometrics
· Translational Research
· Clinical Evaluations and Therapeutic Outcomes
· Regulatory Science
We invite submissions under the following article types:
· Original Research Articles
· Reviews and Mini-reviews
· White Papers, Commentaries, and Editorials
· Meeting Reports
· Brief/Technical Reports and Rapid Communications
· Regulatory Notes
· Tutorials
· Protocols in the Pharmaceutical Sciences
In addition, The AAPS Journal publishes themes, organized by guest editors, which are focused on particular areas of current interest to our field.