Shukla Abhinav A, Jiang Canping, Ma Junfen, Rubacha Michael, Flansburg Lisa, Lee Steven S
Bristol-Myers Squibb Company, 6000 Thompson Road, East Syracuse, New York 13057, USA.
Biotechnol Prog. 2008 May-Jun;24(3):615-22. doi: 10.1021/bp070396j. Epub 2008 Apr 15.
Residual host cell protein impurities (HCPs) are a key component of biopharmaceutical process related impurities. These impurities need to be effectively cleared through chromatographic steps in the downstream purification process to produce safe and efficacious protein biopharmaceuticals. A variety of strategies to demonstrate robust host cell protein clearance using scale-down studies are highlighted and compared. A common strategy is the "spiking" approach, which is widely employed in clearance studies for well-defined impurities. For HCPs this approach involves spiking cell culture harvest, which is rich in host cell proteins, into the load material for all chromatographic steps to assess their clearance ability. However, for studying HCP clearance, this approach suffers from the significant disadvantage that the vast majority of host cell protein impurities in a cell culture harvest sample are not relevant for a chromatographic step that is downstream of the capture step in the process. Two alternative strategies are presented here to study HCP clearance such that relevance of those species for a given chromatographic step is taken into consideration. These include a "bypass" strategy, which assumes that some of the load material for a chromatographic step bypasses that step and makes it into the load for the subsequent step. The second is a "worst-case" strategy, which utilizes information obtained from process characterization studies. This involves operating steps at a combination of their operating parameters within operating ranges that yield the poorest clearance of HCPs over that step. The eluate from the worst case run is carried forward to the next chromatographic step to assess its ability to clear HCPs. Both the bypass and worst-case approaches offer significant advantages over the spiking approach with respect to process relevance of the HCP impurity species being studied. A combination of these small-scale validation approaches with large-scale HCP clearance data from clinical manufacturing and manufacturing consistency runs is used to demonstrate robust HCP clearance for the downstream purification process of an Fc fusion protein. The demonstration of robust HCP clearance through this comprehensive strategy can potentially be used to eliminate the need for routine analytical testing or for establishing acceptance criteria for these impurities as well as to demonstrate robust operation of the entire downstream purification process.
残留宿主细胞蛋白杂质（HCPs）是生物制药过程相关杂质的关键组成部分。这些杂质需要在下游纯化过程中通过色谱步骤有效清除，以生产安全有效的蛋白质生物制药产品。本文重点介绍并比较了多种使用缩小规模研究来证明强大的宿主细胞蛋白清除能力的策略。一种常见策略是“加标”方法，该方法广泛用于明确杂质的清除研究。对于HCPs，此方法涉及将富含宿主细胞蛋白的细胞培养收获液加入所有色谱步骤的上样物料中，以评估其清除能力。然而，对于研究HCP清除，该方法存在一个重大缺点，即细胞培养收获液样品中的绝大多数宿主细胞蛋白杂质与该过程中捕获步骤下游的色谱步骤无关。本文提出了两种替代策略来研究HCP清除，以便考虑这些物质与给定色谱步骤的相关性。其中包括“旁路”策略，该策略假设色谱步骤的一些上样物料绕过该步骤并进入后续步骤的上样物料中。第二种是“最坏情况”策略，该策略利用从工艺表征研究中获得的信息。这涉及在操作范围内以其操作参数的组合来操作步骤，这些参数组合在该步骤中产生最差的HCP清除效果。最坏情况运行的洗脱液进入下一个色谱步骤，以评估其清除HCP的能力。就所研究的HCP杂质种类的工艺相关性而言，旁路和最坏情况方法都比加标方法具有显著优势。这些小规模验证方法与来自临床生产和生产一致性运行的大规模HCP清除数据相结合，用于证明Fc融合蛋白下游纯化过程具有强大的HCP清除能力。通过这种综合策略证明强大的HCP清除能力，有可能用于消除对这些杂质进行常规分析测试或制定验收标准以及证明整个下游纯化过程稳健运行的需求。
