Identification and accurate quantitation of host cell proteins (HCPs) in biotherapeutic drugs has become increasingly important due to the negative impact of certain HCPs on the safety, stability, and other product quality of biotherapeutics. Recently, several lipase HCPs have been identified to potentially cause the enzymatic degradation of polysorbate, a widely used excipient in the formulation of biotherapeutics, which can severely impact the stability and product quality of drug products. In this study, we identified three lipase HCPs that were frequently detected in Chinese hamster ovary (CHO) cell cultures using shotgun proteomics, including phospholipase B-like 2 (PLBL2), lipoprotein lipase (LPL), and lysosomal acid lipase (LIPA). A targeted quantitation method for these three lipase HCPs was developed utilizing liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) with high-resolution multiple-reaction-monitoring (MRMhr) quantitation. The method demonstrated good sensitivity with low limit of quantitation (LLOQ) around 1 ng/mL, and linear dynamic range of three orders of magnitude for the three lipase HCPs. It has been applied for the characterization of process intermediates from various in-house monoclonal antibody (mAb) production. In addition, the method has also been used to evaluate the robustness of clearance for one of the lipase HCPs, PLBL2, under different column purification process conditions.

Decoupling upstream and downstream operations in biopharmaceutical production could enable more flexible manufacturing operations and could allow companies to leverage strategic or financial benefits that would be otherwise unattainable. A decoupling process was developed and scaled up utilizing single-pass tangential flow filtration for volume reduction, followed by bulk freezing in single-use bags prior to purification. Single-pass tangential flow filtration can be used to continuously concentrate harvested cell culture fluid, reducing the volume by 15-25× with a step yield of >96%. These concentration factors were reproduced with a second product, indicating that the process could be amenable to platform processes. Experimental data indicate that the product tested was stable for at least one year at -40 or -70°C. The concentration of the harvested cell culture fluid-either with or without a subsequent period of frozen storage-had no impact on the product quality attributes that were tested. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:405-411, 2018.

Recent interest in continuous manufacturing of biologics has driven the development and evaluation of multicolumn chromatography systems to drive down resin costs by increasing productivity and maximizing resin utilization, especially for the expensive protein A capture step. Single‐pass tangential flow filtration can be used to reduce the volume of perfusion harvest, enabling a further increase in the productivity of the capture step by up to fivefold. However, there are expected to be practical limits for the productivity of the capture step, which must be determined based on the manufacturing batch size, duration, and frequency, especially as it relates to efficient utilization of the column lifetime. For short fed‐batch manufacturing campaigns, intensified capture processes may result in up to 82% lower resin consumption, while avoiding the long‐term storage of used resin. For perfusion processes and longer fed‐batch campaigns, it may be more efficient to operate at a lower productivity that enables the column lifetime to be routinely achieved and achieves the desired resin and buffer savings without introducing unnecessary process risk or complexity. An intensified batch capture process, “super‐batch,” will be compared as an alternative to multicolumn chromatography processes to achieve high productivity and resin utilization with a potentially simpler process.

Biological therapeutics are increasingly being formulated to high protein concentrations to decrease drug substance storage space and increase the flexibility of administration to patients. With the higher protein concentration targets comes added challenges to the downstream purification manufacturing process. Tangential flow filtration (TFF) operations are typically performed to reach target protein concentration. TFF operations for a given drug substance may include an Ultrafiltration and Diafiltration (UFDF) step, or a UFDF step followed by a single pass tangential flow filtration (SPTFF) step. Whether a TFF step achieves a target protein concentration is determined by at‐line protein concentration measurements performed at the completion of a process step. If the measured protein concentration is outside the specified range, the unit operation may need to be restarted, reprocessing may need to be performed, or a batch may need to be terminated. Out of specification protein concentration measurements may be a result of the TFF operation or sample measurement. Increased viscosities associated with high concentration TFF operations pose added challenges to the TFF process and sample measurement. Implementation of an inline process analytical technology (PAT) to monitor real‐time protein concentration during TFF operations has the potential to improve the accuracy of the operations in achieving target protein concentrations. This will result in improved process consistency and efficiency, increased operator confidence and decreased likelihood of batch failures. This paper studies the performance of a K‐Patents PR‐23 refractometer (Vaisala) as a PAT to monitor and control the UFDF and SPTFF unit operations of a commercial scale monoclonal antibody purification process.