The use of monoclonal antibodies in cancer therapy is limited by their cross-reactivity to healthy tissue. Tumor targeting has been improved by generating masked antibodies that are selectively activated in the tumor microenvironment, but each such antibody necessitates a custom design. Here, we present a generalizable approach for masking the binding domains of antibodies with a heterodimeric coiled-coil domain that sterically occludes the complementarity-determining regions. On exposure to tumor-associated proteases, such as matrix metalloproteinases 2 and 9, the coiled-coil peptides are cleaved and antigen binding is restored. We test multiple coiled-coil formats and show that the optimized masking domain is broadly applicable to antibodies of interest. Our approach prevents anti-CD3-associated cytokine release in mice and substantially improves circulation half-life by protecting the antibody from an antigen sink. When applied to antibody–drug conjugates, our masked antibodies are preferentially unmasked at the tumor site and have increased anti-tumor efficacy compared with unmasked antibodies in mouse models of cancer.

单克隆抗体在癌症治疗中的使用受到其与健康组织的交叉反应性的限制。通过产生在肿瘤微环境中选择性激活的掩蔽抗体来改善肿瘤靶向性，但每种此类抗体都需要定制设计。在这里，我们提出了一种通用的方法，用于用空间上封闭互补决定区域的异二聚体卷曲螺旋结构域来掩盖抗体的结合结构域。在暴露于肿瘤相关蛋白酶，例如基质金属蛋白酶 2 和 9 时，卷曲螺旋肽被切割并恢复抗原结合。我们测试了多种盘绕线圈格式，并表明优化的掩蔽域广泛适用于感兴趣的抗体。我们的方法可防止小鼠体内抗 CD3 相关细胞因子的释放，并通过保护抗体免受抗原汇的影响而显着改善循环半衰期。当应用于抗体-药物偶联物时，我们的掩蔽抗体优先在肿瘤部位未掩蔽，与癌症小鼠模型中的未掩蔽抗体相比，具有更高的抗肿瘤功效。