近年来，靶向治疗和免疫治疗显著改善了黑色素瘤的治疗效果。然而，对于无反应或治疗复发的黑色素瘤患者仍然需要治疗策略。为了发现适用于黑色素瘤的抗体药物偶联物（ADC）可控制的细胞表面靶点，我们利用全蛋白组规模的抗体阵列平台（PETAL）开发了黑色素瘤细胞表面结合抗体（pAbs）的图谱。通过对pAbs的靶点鉴定，我们开发了针对LGR6、TRPM1、ASAP1和MUC18等靶点的黑色素瘤细胞杀伤ADC。在各种黑色素瘤亚型的肿瘤细胞和肿瘤浸润血管中，MUC18过度表达，使其成为潜在的双子房和普遍的黑色素瘤治疗靶点。基于拓扑异构酶I抑制剂exatecan和自解脱的T基团，MUC18指向的ADC AMT-253相比微管抑制剂基础的对比物具有更高的治疗指数，并且在猴子中具有良好的药代动力学和耐受性。AMT-253通过DNA损伤和凋亡表现出MUC18特异性细胞毒性和强大的旁观者杀伤效应，在黑色素瘤细胞系和患者衍生的异种移植模型中表现出强效的抗肿瘤活性。通过小鼠MUC18特异性抗体-T1000-exatecan偶联物靶向肿瘤血管抑制了人黑色素瘤异种移植瘤的生长。AMT-253与抗血管生成剂的联合治疗在腔上黑色素瘤模型中产生了比单一药物更高的疗效。除了黑色素瘤，AMT-253在广泛表达MUC18的实体肿瘤中也具有疗效。这里展示的T基团-exatecan连接剂有效的靶点/抗体发现，可能有助于发现新的ADC，改善癌症治疗。

Recent advances in targeted therapy and immunotherapy have substantially improved the treatment of melanoma. However, therapeutic strategies are still needed for unresponsive or treatment-relapsed melanoma patients. To discover antibody-drug conjugate (ADC)-tractable cell surface targets for melanoma, we developed an atlas of melanoma cell surface binding antibodies (pAbs) using a proteome-scale antibody array platform (PETAL). Target identification of pAbs led to development of melanoma cell killing ADCs against LGR6, TRPM1, ASAP1, and MUC18, among others. MUC18 was overexpressed in both tumor cells and tumor-infiltrating blood vessels across major melanoma subtypes, making it a potential dual-compartment and universal melanoma therapeutic target. AMT-253, an MUC18-directed ADC based on topoisomerase I inhibitor exatecan and a self-immolative T moiety, had a higher therapeutic index compared to its microtubule inhibitor-based counterpart and favorable pharmacokinetics and tolerability in monkeys. AMT-253 exhibited MUC18-specific cytotoxicity through DNA damage and apoptosis and a strong bystander killing effect, leading to potent antitumor activities against melanoma cell line and patient-derived xenograft models. Tumor vasculature-targeting by a mouse MUC18-specific antibody-T1000-exatecan conjugate inhibited tumor growth in human melanoma xenografts. Combination therapy of AMT-253 with an anti-angiogenic agent generated higher efficacy than single agent in a mucosal melanoma model. Beyond melanoma, AMT-253 was also efficacious in a wide range of MUC18-expressing solid tumors. Efficient target/antibody discovery in combination with the T moiety-exatecan linker-payload exemplified here may facilitate discovery of new ADC to improve cancer treatment.