Department of Radiation Oncology, University of Washington, Seattle, Washington, United States of America.
Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.
PLoS One. 2018 Oct 18;13(10):e0205135. doi: 10.1371/journal.pone.0205135. eCollection 2018.
The objective of this study was to translate reaction conditions and quality control methods used for production of an astatine-211(211At)-labeled anti-CD45 monoclonal antibody (MAb) conjugate, 211At-BC8-B10, from the laboratory setting to cGMP production. Five separate materials were produced in the preparation of 211At-BC8-B10: (1) p-isothiocyanato-phenethyl-closo-decaborate(2-) (B10-NCS), (2) anti-CD45 MAb, BC8, (3) BC8-B10 MAb conjugate, (4) [211At]NaAt, and (5) 211At-BC8-B10. The 211At-labeling reagent, B10-NCS, was synthesized as previously reported. BC8 was produced, then conjugated with B10-NCS under cGMP conditions to form BC8-B10. [211At]NaAt was produced by α-irradiation of Bi targets, followed by isolation of the 211At using a "wet chemistry" method. The clinical product, 211At-BC8-B10, was prepared by reacting [211At]NaAt with BC8-B10 in NH4OAc buffer (pH 5.5) for 2 min at room temperature, followed by size-exclusion chromatography purification. Quality control tests conducted on the 211At-BC8-B10 included evaluations for purity and identity, as well as pyrogen and sterility tests. Stability of the 211At-BC8-B10 in 25 mg/mL sodium ascorbate solution was evaluated at 1, 2, 4, 6 and 21 h post isolation. For qualification, three consecutive 211At-BC8-B10 clinical preparations were successfully conducted in the cGMP suite, and an additional cGMP clinical preparation was carried out to validate each step required to deliver 211At-BC8-B10 to a patient. These cGMP preparations provided 0.80-1.28 Gbq (21.5-34.5 mCi) of 211At-BC8-B10 with radiochemical purity of >97%. The preparations were found to be sterile and have a pyrogen level <0.50 EU/mL. Cell binding was retained by the 211At-BC8-B10. 211At-BC8-B10 in ascorbic acid solution demonstrated a radiochemical stability of >95% for up to 21 h at room temperature. The experiments conducted have defined conditions for translation of 211At-BC8-B10 production from the laboratory to cGMP suite. This study has allowed the initiation of a phase I/II clinical trial using 211At-BC8-B10 (NCT03128034).
本研究的目的是将在实验室环境中用于生产放射性标记抗 CD45 单克隆抗体（MAb）缀合物 211At-BC8-B10 的反应条件和质量控制方法转化为符合 cGMP 生产的条件。在制备 211At-BC8-B10 时，共制备了五种不同的材料：（1）p-异硫氰酸基苯乙基 closo-癸硼酸盐（2-）（B10-NCS），（2）抗 CD45 MAb，BC8，（3）BC8-B10 MAb 缀合物，（4）[211At]NaAt，和（5）211At-BC8-B10。放射性标记试剂 B10-NCS 如前所述合成。制备 BC8 后，在 cGMP 条件下与 B10-NCS 偶联，形成 BC8-B10。[211At]NaAt 通过α辐照 Bi 靶标产生，然后使用“湿化学”方法分离 211At。临床产品 211At-BC8-B10 通过在室温下用 NH4OAc 缓冲液（pH 5.5）将[211At]NaAt 与 BC8-B10 反应 2 分钟制备，然后通过凝胶渗透色谱法纯化。对 211At-BC8-B10 进行的质量控制测试包括纯度和身份评估，以及热原和无菌测试。在分离后 1、2、4、6 和 21 小时评估了 211At-BC8-B10 在 25mg/mL 抗坏血酸钠溶液中的稳定性。为了验证，在 cGMP 套件中成功进行了三次连续的 211At-BC8-B10 临床制剂制备，并进行了额外的 cGMP 临床制剂制备，以验证向患者提供 211At-BC8-B10 所需的每个步骤。这些 cGMP 制剂提供了 0.80-1.28GBq（21.5-34.5mCi）的 211At-BC8-B10，放射化学纯度>97%。制剂无菌且热原水平<0.50EU/mL。211At-BC8-B10 保持细胞结合。在室温下，抗坏血酸溶液中的 211At-BC8-B10 表现出>95%的放射化学稳定性，可稳定 21 小时。进行的实验定义了将 211At-BC8-B10 的生产从实验室转化为 cGMP 套件的条件。本研究允许使用 211At-BC8-B10 启动 I/II 期临床试验（NCT03128034）。
