89Zr标记达雷妥尤单克隆抗体用于多发性骨髓瘤显像诊断的临床前评价

目的:制备⁸⁹Zr标记达雷妥尤单克隆抗体(Daratumumab),并评价其用于多发性骨髓瘤(MM)显像诊断的可行性。方法:依据⁸⁹Y(p,n)⁸⁹Zr核反应原理,采用回旋加速器固体靶系统(30μA,1.5 h)和自动化纯化模块生产⁸⁹Zr,检测核纯度、半衰期和杂质金属含量。将去铁胺(DFO)与Daratumumab偶联后再与⁸⁹Zr螯合制备⁸⁹Zr-DFO-Daratumumab,进行连续3批产品的质量控制分析。在正常家兔体内进行药代动力学评价,在原位骨髓瘤小鼠模型中进行⁸⁹Zr-DFO-Daratumumab microPET/CT显像。采用两独立样本t检验比较原位骨髓瘤和正常骨骼SUV的差异。结果:获得⁸⁹Zr纯品约560 MBq,γ能谱仪显示只有2个⁸⁹Zr特征能峰(909 keV和511 keV),半衰期为78.2 h,金属杂质含量较少。⁸⁹Zr-DFO-Daratumumab的pH值为7.2左右,放化纯大于99%,体外稳定性良好,无菌和内毒素检测通过。家兔体内药代动力学研究显示,随时间推移和体内代谢,⁸⁹Zr-DFO-Daratumumab逐渐由血液分布于肝、脾、肾和骨关节等。原位骨髓瘤小鼠⁸⁹Zr-DFO-Daratumumab microPET/CT显像示,⁸⁹Zr-DFO-Daratumumab在原位骨髓瘤的SUV高于正常骨骼(2 h:0.22±0.02和0.06±0.00;1 d:0.38±0.01和0.08±0.00;t值:8.89、21.90,均P=0.001)。结论:成功制备⁸⁹Zr和⁸⁹Zr-DFO-Daratumumab,并完成相关质量控制与体内外生物学评价,验证了⁸⁹Zr-DFO-Daratumumab用于MM显像诊断的可行性,为临床转化打下基础。

Preclinical evaluation of 89Zr labeled Daratumumab for imaging diagnosis of multiple myeloma

Objective To prepare ⁸⁹Zr labeled Daratumumab and evaluate its feasibility in the imaging diagnosis of multiple myeloma(MM).Methods According to the principle of ⁸⁹Y(p,n)⁸⁹Zr nuclear reaction,⁸⁹Zr was produced by cyclotron solid target system(30μA,1.5 h)and automatic purification module.The radionuclide purity,half-life and impurity metal ion concentration were detected.Desferrioxamine(DFO)was coupled with Daratumumab and then chelated with ⁸⁹Zr to prepare ⁸⁹Zr-DFO-Daratumumab.The quality control analyses of three consecutive batches were carried out.Pharmacokinetic evaluation and ⁸⁹Zr-DFO-Daratumumab microPET/CT imaging were performed in normal rabbits and orthotopic myeloma mouse models,respectively.The SUV in situ myeloma and that in normal bone were compared by independent-sample t test.Results About 560 MBq of ⁸⁹Zr was obtained,and there were only two characteristic energy peaks of ⁸⁹Zr(909 keV and 511 keV)byγspectrometer.The half-life of ⁸⁹Zr was 78.2 h,and the content of metal impurities was small.⁸⁹Zr-DFO-Daratumumab was prepared with pH of 7.2,radiochemical purity of more than 99%,good stability in vitro,and sterility and endotoxin tests were passed.Pharmacokinetic studies in rabbits showed that ⁸⁹Zr-DFO-Daratumumab was gradually distributed from blood to liver,spleen,kidney and bone joints over time and metabolism.The results of microPET/CT imaging in orthotopic myeloma mouse models showed that the SUVs of ⁸⁹Zr-DFO-daratumumab in situ myeloma were significantly higher than those in normal bone(2 h:0.22±0.02 vs 0.06±0.00;1 d:0.38±0.01 vs 0.08±0.00;t values:8.89,21.90,both P=0.001).Conclusion ⁸⁹Zr and ⁸⁹Zr-DFO-daratumumab are successfully prepared,and relevant quality control and biological evaluation in vivo and in vitro are completed,which verify the feasibility of ⁸⁹Zr-DFO-Daratumumab in the imaging diagnosis of MM,thus laying a foundation for clinical transformation.