An antigen binding fragment (BFab) derived from a tumor-associated mucin 1–sialoglycotope antigen (CA6) targeting antibody (huDS6) was engineered. We synthesized a companion diagnostic positron emission tomography (PET) tracer by radiolabeling BFab with [⁶⁴Cu] to measure CA6 expression on cancer tissues prior to anti-human CA6 (huDS6-DM4 antibody-drug conjugate) therapy for ovarian and breast cancer patients. After chemotherapy, the ovarian patient received PET scan with ¹⁸F-2-fluoro-2-deoxyglucose ([¹⁸F]FDG: 10 mCi), followed by [⁶⁴Cu]-DOTA-BFab ([⁶⁴Cu]BFab; 5.5 mCi) 1 week later for PET scanning of CA6 expression and subsequent surgery. The breast cancer patient was treated with chemotherapy before primary tumor resection and subsequent [¹⁸F]FDG-PET scan. 4 weeks later the patient received of [⁶⁴Cu]BFab (11.7 mCi) for CA6 PET scan. Whole body [¹⁸F]FDG-PET of the breast cancer patient indicated FDG-avid tumor metastases to the liver, bilateral hila and thoracic spine, but no uptake was observed for the ovarian patient. Each patient was also imaged by PET/CT with [⁶⁴Cu]BFab at 1 and 24 hours after tracer administration. The [⁶⁴Cu]BFab tracer was well tolerated by both patients without adverse effects, and no significant tracer uptake was observed in both patients. Immunohistochemistry (IHC) data indicated CA6 expressions were weak to intermediate and matched with the [⁶⁴Cu]BFab-PET signals.

工程化了源自肿瘤相关粘蛋白 1-唾液酸糖位抗原 (CA6) 靶向抗体 (huDS6) 的抗原结合片段 (BFab)。^{我们合成了伴随诊断正电子发射断层扫描 (PET) 示踪剂，通过用 [ 64} Cu]放射性标记 BFab来测量卵巢癌和乳腺癌患者的抗人 CA6（huDS6-DM4 抗体-药物偶联物）治疗之前癌组织上的 CA6 表达。化疗后，卵巢患者接受¹⁸ F-2-fluoro-2-deoxyglucose ([ ¹⁸ F]FDG: 10 mCi) 的 PET 扫描，随后是 [ ⁶⁴ Cu]-DOTA-BFab ([ ⁶⁴Cu]BFab; 5.5 mCi) 1 周后进行 CA6 表达的 PET 扫描和随后的手术。乳腺癌患者在原发性肿瘤切除和随后的 [ ¹⁸ F]FDG-PET 扫描前接受了化疗。4 周后，患者接受了 [ ⁶⁴ Cu]BFab (11.7 mCi) 用于 CA6 PET 扫描。乳腺癌患者的全身[ ¹⁸ F]FDG-PET显示FDG-avid肿瘤转移至肝脏、双侧肺门和胸椎，但卵巢患者未观察到摄取。在示踪剂给药后 1 小时和 24 小时，每位患者还通过 PET/CT 用 [ ⁶⁴ Cu]BFab 成像。[ ⁶⁴两名患者均对 Cu]BFab 示踪剂耐受良好，没有不良反应，并且在两名患者中均未观察到显着的示踪剂摄取。免疫组织化学 (IHC) 数据表明 CA6 表达弱到中等，并与 [ ⁶⁴ Cu]BFab-PET 信号匹配。