Recent advances in large-scale production of monoclonal antibodies and related proteins

Therapeutic monoclonal antibodies in allergy: Targeting IgE, cytokine, and alarmin pathways

The etiology of allergy is closely linked to type 2 inflammatory responses ultimately leading to the production of allergen-specific immunoglobulin E (IgE), a key driver of many allergic conditions. At a high level, initial allergen exposure disrupts epithelial integrity, triggering local inflammation via alarmins including IL-25, IL-33, and TSLP, which activate type 2 innate lymphoid cells as well as other immune cells to secrete type 2 cytokines IL-4, IL-5 and IL-13, promoting Th2 cell development and eosinophil recruitment. Th2 cell dependent B cell activation promotes the production of allergen-specific IgE, which stably binds to basophils and mast cells. Rapid degranulation of these cells upon allergen re-exposure leads to allergic symptoms. Recent advances in our understanding of the molecular and cellular mechanisms underlying allergic pathophysiology have significantly shaped the development of therapeutic intervention strategies. In this review, we highlight key therapeutic targets within the allergic cascade with a particular focus on past, current and future treatment approaches using monoclonal antibodies. Specific targeting of alarmins, type 2 cytokines and IgE has shown varying degrees of clinical benefit in different allergic indications including asthma, chronic spontaneous urticaria, atopic dermatitis, chronic rhinosinusitis with nasal polyps, food allergies and eosinophilic esophagitis. While multiple therapeutic antibodies have been approved for clinical use, scientists are still working on ways to improve on current treatment approaches. Here, we provide context to understand therapeutic targeting strategies and their limitations, discussing both knowledge gaps and promising future directions to enhancing clinical efficacy in allergic disease management.

Antibody-ligand interactions on a high-capacity staphylococcal protein A resin

Staphylococcal protein-A affinity chromatography has been optimized for antibody purification, achieving a current capacity of up to 90 mg/ml in packed bed. The morphology of the particles, the number of antibodies bound per ligand and the spatial arrangement of the ligands were assessed by in-situ Small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) combined with measurement of adsorption isotherms. We employed SAXS measurements to probe the nanoscale structure of the chromatographic resin. From scanning electron microcopy, the morphology and area of the beads were obtained. The adsorption isotherm revealed a bi-Langmuirian behavior where the association constant varied with the critical bulk concentration, indicating multilayer adsorption. Determining the antibody-ligand stoichiometry was crucial for understanding the adsorption mechanism, which was estimated to be 4 at lower concentrations and 4.5 at higher concentrations, suggestive of reversible protein-protein interactions. The same results were reached from the in-situ small angle X-ray scattering measurements. A stoichiometry of 6 cannot be achieved since the two protein A monomers are anchored to the stationary phase and thus sterically hindered. Normalization through ellipsoids facilitated SAXS analysis, enabling the determination of distances between ligands and antibody-ligand complexes. Density fluctuations were examined by subtracting the elliptical fit, providing insights into ligand density distribution. The dense ligand packing of TOYOPEARL® AF-rProtein A HC was confirmed, making further increases in ligand density impractical. Additionally, SAXS analysis revealed structural rearrangements of the antibody-ligand complex with increasing antibody surface load, suggesting reversible association of antibodies.

Quantification of human intravenous immunoglobulin from plasma and in process samples by affinity chromatography

Advances in affinity chromatography now make it possible to analyze immunoglobulin G from plasma and its fractions with a simple chromatographic method. Ligands derived from camelid antibodies have been developed which have affinity to all 4 subclasses of human IgG without a cross reactivity to other immunoglobulins. The commercially available Capture Select FcXL is the basis for a simple method for direct quantification of immunoglobulin G from plasma or from fractions from cold ethanol precipitation. After direct injection of the sample into the column the unbound proteins are washed out with equilibration buffer and eluted with a pH-step. The elution the peak is integrated, and quantity is derived form a standard curve. The limit of detection with 40 µg/mL, and a linearity up to 250 µg/mL allows an analysis of samples ranging from 0.04 to 50 mg/mL using varying injection volume without further dilution and the two-wavelength detection. A full cycle is completed within five minutes. This method can serve as orthogonal method for in-process control but also for process development.

Methodology for fast development of digital solutions in integrated continuous downstream processing

The methodology for production of biologics is going through a paradigm shift from batch-wise operation to continuous production. Lot of efforts are focused on integration, intensification, and continuous operation for decreased foot-print, material, equipment, and increased productivity and product quality. These integrated continuous processes with on-line analytics become complex processes, which requires automation, monitoring, and control of the operation, even unmanned or remote, which means bioprocesses with high level of automation or even autonomous capabilities. The development of these digital solutions becomes an important part of the process development and needs to be assessed early in the development chain. This work discusses a platform that allows fast development, advanced studies, and validation of digital solutions for integrated continuous downstream processes. It uses an open, flexible, and extendable real-time supervisory controller, called Orbit, developed in Python. Orbit makes it possible to communicate with a set of different physical setups and on the same time perform real-time execution. Integrated continuous processing often implies parallel operation of several setups and network of Orbit controllers makes it possible to synchronize complex process system. Data handling, storage, and analysis are important properties for handling heterogeneous and asynchronous data generated in complex downstream systems. Digital twin applications, such as advanced model-based and plant-wide monitoring and control, are exemplified using computational extensions in Orbit, exploiting data and models. Examples of novel digital solutions in integrated downstream processes are automatic operation parameter optimization, Kalman filter monitoring, and model-based batch-to-batch control.

Purification of secretory IgA monoclonal antibodies enriched fraction directly from cell culture medium using aqueous two-phase systems

Secretory immunoglobulin A [sIgA] is a promising candidate for enteric therapeutics applications, and several sIgA-based constructs are currently being developed by groups utilizing clarified Chinese hamster ovary [CHO] cell culture supernatants. To the monoclonal antibody downstream processing typically entails chromatography-based purification processes beginning with Protein A chromatography. In this paper, aqueous two-phase systems [ATPS] were employed for the preliminary purification of secretory immunoglobulin A [sIgA] monoclonal antibody [mAb] from clarified CHO-cell culture supernatants. A 24 full factorial design was utilized. The influence of various process parameters such as pH, PEG molecular weight [MPEG], PEG concentration [CPEG], and phosphate salt concentration [CPHO], on the sIgA partition coefficient [K sIgA] and the recovery index [Y] in the PEG phase were evaluated. The Elisa assay revealed that, in the ATPS conditions tested, sIgA mAb was mostly detected in PEG upper phase. Run 14 with the highest sIgA activity exhibited the following conditions: MPEG 8.000 g/mol, CPEG 12,5 %, pH 7,0 and CPHO 10 %, and a sIgA K of 94.50 and a recovery index [Y] of 33.52 %. The proposed platform provides straightforward implementation, yields comparable results, and offers significantly improved economics for manufacturing sIgA mAb biotherapeutics.

CRISPR-Cas9 knockout screen informs efficient reduction of the Komagataella phaffii secretome

BACKGROUND

The yeast Komagataella phaffii is widely used for manufacturing recombinant proteins, but secreted titers of recombinant proteins could be improved by genetic engineering. In this study, we hypothesized that cellular resources could be redirected from production of endogenous proteins to production of recombinant proteins by deleting unneeded endogenous proteins. In non-model microorganisms such as K. phaffii, however, genetic engineering is limited by lack gene annotation and knowledge of gene essentiality.

RESULTS

We identified a set of endogenous secreted proteins in K. phaffii by mass spectrometry and signal peptide prediction. Our efforts to disrupt these genes were hindered by limited annotation of essential genes. To predict essential genes, therefore, we designed, transformed, and sequenced a pooled library of guide RNAs for CRISPR-Cas9-mediated knockout of all endogenous secreted proteins. We then used predicted gene essentiality to guide iterative disruptions of up to 11 non-essential genes. Engineered strains exhibited a ~20× increase in the production of human serum albumin and a twofold increase in the production of a monoclonal antibody.

CONCLUSIONS

We demonstrated that disruption of as few as six genes can increase production of recombinant proteins. Further reduction of the endogenous proteome of K. phaffii may further improve strain performance. The pooled library of secretome-targeted guides for CRISPR-Cas9 and knowledge of gene essentiality reported here will facilitate future efforts to engineer K. phaffii for production of other recombinant proteins and enzymes.

Characterization of the Charge Heterogeneity of a Monoclonal Antibody That Binds to Both Cation Exchange and Anion Exchange Columns under the Same Binding Conditions

Therapeutic antibodies play an important role in the public healthcare system to treat patients with a variety of diseases. Protein characterization using an array of analytical tools provides in-depth information for drug quality, safety, efficacy, and the further understanding of the molecule. A therapeutic antibody candidate MAB1 exhibits unique binding properties to both cation and anion exchange columns at neutral pH. This uniqueness disrupts standard purification processes and necessitates adjustments in manufacturing. This study identifies that the charge heterogeneity of MAB1 is primarily due to the N-terminal cyclization of glutamine to pyroglutamine and, to a lesser extent, succinimide intermediate, deamidation, and C-terminal lysine. Using three approaches, i.e., deferential chemical labeling, H/D exchange, and molecular modeling, the binding to anion exchange resins is attributed to negatively charged patches on the antibody's surface, involving specific carboxylic acid residues. The methodologies shown here can be extended to study protein binding orientation in column chromatography.

Broadly neutralizing antibodies for HIV prevention: a comprehensive review and future perspectives

SUMMARYThe human immunodeficiency virus (HIV) epidemic remains a formidable global health concern, with 39 million people living with the virus and 1.3 million new infections reported in 2022. Despite anti-retroviral therapy's effectiveness in pre-exposure prophylaxis, its global adoption is limited. Broadly neutralizing antibodies (bNAbs) offer an alternative strategy for HIV prevention through passive immunization. Historically, passive immunization has been efficacious in the treatment of various diseases ranging from oncology to infectious diseases. Early clinical trials suggest bNAbs are safe, tolerable, and capable of reducing HIV RNA levels. Although challenges such as bNAb resistance have been noted in phase I trials, ongoing research aims to assess the additive or synergistic benefits of combining multiple bNAbs. Researchers are exploring bispecific and trispecific antibodies, and fragment crystallizable region modifications to augment antibody efficacy and half-life. Moreover, the potential of other antibody isotypes like IgG3 and IgA is under investigation. While promising, the application of bNAbs faces economic and logistical barriers. High manufacturing costs, particularly in resource-limited settings, and logistical challenges like cold-chain requirements pose obstacles. Preliminary studies suggest cost-effectiveness, although this is contingent on various factors like efficacy and distribution. Technological advancements and strategic partnerships may mitigate some challenges, but issues like molecular aggregation remain. The World Health Organization has provided preferred product characteristics for bNAbs, focusing on optimizing their efficacy, safety, and accessibility. The integration of bNAbs in HIV prophylaxis necessitates a multi-faceted approach, considering economic, logistical, and scientific variables. This review comprehensively covers the historical context, current advancements, and future avenues of bNAbs in HIV prevention.

Host cell protein networks as a novel co-elution mechanism during protein A chromatography

Host cell proteins (HCPs) are process-related impurities of therapeutic proteins produced in for example, Chinese hamster ovary (CHO) cells. Protein A affinity chromatography is the initial capture step to purify monoclonal antibodies or Fc-based proteins and is most effective for HCP removal. Previously proposed mechanisms that contribute to co-purification of HCPs with the therapeutic protein are either HCP-drug association or leaching from chromatin heteroaggregates. In this study, we analyzed protein A eluates of 23 Fc-based proteins by LC-MS/MS to determine their HCP content. The analysis revealed a high degree of heterogeneity in the number of HCPs identified in the different protein A eluates. Among all identified HCPs, the majority co-eluted with less than three Fc-based proteins indicating a drug-specific co-purification for most HCPs. Only ten HCPs co-purified with over 50% of the 23 Fc-based proteins. A correlation analysis of HCPs identified across multiple protein A eluates revealed their co-elution as HCP groups. Functional annotation and protein interaction analysis confirmed that some HCP groups are associated with protein-protein interaction networks. Here, we propose an additional mechanism for HCP co-elution involving protein-protein interactions within functional networks. Our findings may help to guide cell line development and to refine downstream purification strategies.

Biosimilars production in Africa opportunities & challenges

The healthcare systems of African nations heavily rely on importing and repackaging biological medicine. More than 70% of the pharmaceutical products consumed in Africa are imported. The localization of biosimilar production can have a positive impact on the availability and cost of these products by reducing the expenses for African governments and making essential healthcare products more accessible to the population. However, it is evident that the developing countries, particularly African nations, face various obstacles and difficulties in localizing biosimilar production. These challenges encompass development, manufacturing, evaluation, and registration processes. In this review, we will highlight the significant hurdles and achievements encountered during the localization process of biosimilars.

Therapeutic proteins: developments, progress, challenges, and future perspectives

Proteins are considered magic molecules due to their enormous applications in the health sector. Over the past few decades, therapeutic proteins have emerged as a promising treatment option for various diseases, particularly cancer, cardiovascular disease, diabetes, and others. The formulation of protein-based therapies is a major area of research, however, a few factors still hinder the large-scale production of these therapeutic products, such as stability, heterogenicity, immunogenicity, high cost of production, etc. This review provides comprehensive information on various sources and production of therapeutic proteins. The review also summarizes the challenges currently faced by scientists while developing protein-based therapeutics, along with possible solutions. It can be concluded that these proteins can be used in combination with small molecular drugs to give synergistic benefits in the future.

Exploring preferred binding domains of IgG1 mAbs to multimodal adsorbents using a combined biophysics and simulation approach

In this work, we employ a recently developed biophysical technique that uses diethylpyrocarbonate (DEPC) covalent labeling and mass spectrometry for the identification of mAb binding patches to two multimodal cation exchange resins at different pH. This approach compares the labeling results obtained in the bound and unbound states to identify residues that are sterically shielded and thus located in the mAb binding domains. The results at pH 6 for one mAb (mAb B) indicated that while the complementarity determining region (CDR) had minimal interactions with both resins, the FC domain was actively involved in binding. In contrast, DEPC/MS data with another mAb (mAb C) indicated that both the CDR and FC domains were actively involved in binding. These results corroborated chromatographic retention data with these two mAbs and their fragments and helped to explain the significantly stronger retention of both the intact mAb C and its Fab fragment. In contrast, labeling results with mAb C at pH 7, indicated that only the CDR played a significant role in resin binding, again corroborating chromatographic data. The binding domains identified from the DEPC/MS experiments were also examined using protein surface hydrophobicity maps obtained using a recently developed sparse sampling molecular dynamics (MD) approach in concert with electrostatic potential maps. These results demonstrate that the DEPC covalent labeling/mass spectrometry technique can provide important information about the domain contributions of multidomain proteins such as monoclonal antibodies when interacting with multimodal resins over a range of pH conditions.

Digital twin in high throughput chromatographic process development for monoclonal antibodies

The monoclonal antibody (mAb) industry is becoming increasingly digitalized. Digital twins are becoming increasingly important to test or validate processes before manufacturing. High-Throughput Process Development (HTPD) has been progressively used as a tool for process development and innovation. The combination of High-Throughput Screening with fast computational methods allows to study processes in-silico in a fast and efficient manner. This paper presents a hybrid approach for HTPD where equal importance is given to experimental, computational and decision-making stages. Equilibrium adsorption isotherms of 13 protein A and 16 Cation-Exchange resins were determined with pure mAb. The influence of other components in the clarified cell culture supernatant (harvest) has been under-investigated. This work contributes with a methodology for the study of equilibrium adsorption of mAb in harvest to different protein A resins and compares the adsorption behavior with the pure sample experiments. Column chromatography was modelled using a Lumped Kinetic Model, with an overall mass transfer coefficient parameter (kov). The screening results showed that the harvest solution had virtually no influence on the adsorption behavior of mAb to the different protein A resins tested. kov was found to have a linear correlation with the sample feed concentration, which is in line with mass transfer theory. The hybrid approach for HTPD presented highlights the roles of the computational, experimental, and decision-making stages in process development, and how it can be implemented to develop a chromatographic process. The proposed white-box digital twin helps to accelerate chromatographic process development.

Progress of ligand-modified agarose microspheres for protein isolation and purification

Proteins are the material basis of life and the primary carriers of life activities, containing various impurities that must be removed before use. To keep pace with the increasing complexity of protein samples, it is essential to constantly work on developing new purification technologies for downstream processes. While traditional downstream purification methods rely heavily on protein A affinity chromatography, there is still a lot of interest in finding safer and more cost-effective alternatives to protein A. Many non-affinity ligands and technologies have also been developed in biological purification recently. Here, the current status of biotechnology and the progress of protein separation technology from 2018 to 2023 are reviewed from the aspects of new preparation methods and new composite materials of commonly used separation media. The research status of new ligands with different mechanisms of action was reviewed, including the expanded application of affinity ligands, the development prospect of biotechnology such as polymer grafting, continuous column technology, and its new applications.

On-line PAT based monitoring and control of resin aging in protein A chromatography for COGs reduction

Resin aging is a common occurrence in chromatographic processes and generally influenced by factors such as cleaning procedure and composition of the feed stream. Two major events occur along with protein fouling, one is the loss of protein A ligand and the other is non-specific, irreversible interactions of foulants with resin particles. Both these are responsible for resin aging. As a result, the performance of the resin suffers a fall, and this can be quantified through indicators like reduction in dynamic binding capacity, increased column pressure, or peak broadening. The number of reuse cycles of a resin has a major influence on the cost per batch. This is even more significant in the case of protein A resin, which is the primary cost driver for downstream processing. In this work, we first identify chromatogram characteristics that correlate to resin aging. Next, we propose a data monitoring-based tool for prediction of resin aging. Principal component analysis of the UV data of Mab 1 showed a deviation at 120th cycle and an out of specification at around 149th cycle, corroborating with yield decline. Batch level modelling could deliver a predictable trend for resin aging and was demonstrated for two different Mabs (Mab1 and Mab2). The results demonstrate that significant resin aging can be detected 20-25 cycles prior to observable yield decline. A control strategy has been suggested such that once the deviation has been detected, additional resin cleaning is triggered. Overall, a 50-100 Protein A cycle enhancement in resin lifespan could be achieved.

Development of continuous processing platform utilizing aqueous two-phase extraction for purification of monoclonal antibodies

Monoclonal antibody downstream processing typically entails chromatography-based purification processes beginning with Protein A chromatography, accounting for 50 % of the total manufacturing expense. Alternatives to protein A chromatography have been explored by several researchers. In this paper, aqueous two-phase extraction (ATPE) has been proposed for continuous processing of monoclonal antibodies (mAbs) as an alternative to the traditional protein A chromatography. The PEG-sulfate system has been employed for phase formation in ATPE, and the mAb is separated in the salt phase, while impurities like high molecular weight (HMW) and host cell proteins (HCPs) are separated in the PEG phase. Following ATPE of clarified cell culture harvest, yield of ≥ 80 % and purity of ≥ 97 % were achieved in the salt phase. Considerable (28 %) reduction in consumable cost has been estimated when comparing the proposed platform to the traditional protein A based platform. The outcomes demonstrate that ATPE can be a potentially effective substitute for the traditional Protein A chromatography for purification of mAbs. The proposed platform offers easy implementation, delivers comparative results, and offers significantly better economics for manufacturing mAb-based biotherapeutics.

Predictive mechanistic modeling of loading and elution in protein A chromatography

Protein A chromatography is an enabling technology in current manufacturing processes of monoclonal antibodies (mAbs) and mAb derivatives, largely due to its ability to reduce the levels of process-related impurities by several orders of magnitude. Despite its widespread application, the use of mathematical modeling capable of accurately predicting the full protein A chromatographic process, including loading, post-loading wash and elution stages, has been limited. This work describes a mechanistic modeling approach utilizing the general rate model (GRM), the capabilities of which are explored and optimized using two isotherm models. Isotherm parameters were estimated by inverse-fitting simulated breakthrough curves to experimental data at various pH values. The parameter values so obtained were interpolated across the relevant pH range using a best-fit curve, thus enabling their use in predictive modeling, including of elution over a range of pH. The model provides accurate predictions (< 3% mean error in 10% dynamic binding capacity predictions and ∼ 5% mean error in elution mass and pool volume predictions, both on scale-up) for various residence times, buffer conditions and elution schemes and its effectiveness for use in scale-up and process development is shown by applying the same parameters to larger columns and a wider range of residence times.

tANCHOR fast and cost-effective cell-based immunization approach with focus on the receptor-binding domain of SARS-CoV-2

Successful induction of antibodies in model organisms like mice depends strongly on antigen design and delivery. New antigen designs for immunization are helpful for developing future therapeutic monoclonal antibodies (mAbs). One of the gold standards to induce antibodies in mice is to express and purify the antigen for vaccination. This is especially time-consuming when mAbs are needed rapidly. We closed this gap and used the display technology tetraspanin anchor to develop a reliable immunization technique without the need to purify the antigen. This technique is able to speed up the immunization step enormously and we have demonstrated that we were able to induce antibodies against different proteins with a focus on the receptor-binding domain of SARS-CoV-2 and the extracellular loop of canine cluster of differentiation 20 displayed on the surface of human cells.

Application of platform process development approaches to the manufacturing of Mabcalin™ bispecifics

Bispecific biotherapeutics offer potent and highly specific treatment options in oncology and immuno-oncology. However, many bispecific formats are prone to high levels of aggregation and instability, leading to prolonged development timelines, inefficient manufacturing, and high costs. The novel class of Mabcalin™ molecules consist of Anticalin® proteins fused to an IgG and are currently being evaluated in pre-clinical and clinical studies. Here, we describe a robust high-yield manufacturing platform for these therapeutic fusion proteins providing data up to commercially relevant scales. A platform upstream process was established for one of the Mabcalin bispecifics and then applied to other clinically relevant drug candidates with different IgG target specificities. Process performance was compared in 3 L bioreactors and production was scaled-up to up to 1000 L for confirmation. The Mabcalin proteins' structural and biophysical similarities enabled a downstream platform approach consisting of initial protein A capture, viral inactivation, mixed-mode anion exchange polishing, second polishing by cation exchange or hydrophobic interaction chromatography, viral filtration, buffer exchange and concentration by ultrafiltration/diafiltration. All three processes met their target specifications and achieved comparable clearance of impurities and product yields across scales. The described platform approach provides a fast and economic path to process confirmation and is well comparable to classical monoclonal antibody approaches in terms of costs and time to clinic.

Current challenges and recent advances on the path towards continuous biomanufacturing

Continuous biopharmaceutical manufacturing is currently a field of intense research due to its potential to make the entire production process more optimal for the modern, ever-evolving biopharmaceutical market. Compared to traditional batch manufacturing, continuous bioprocessing is more efficient, adjustable, and sustainable and has reduced capital costs. However, despite its clear advantages, continuous bioprocessing is yet to be widely adopted in commercial manufacturing. This article provides an overview of the technological roadblocks for extensive adoptions and points out the recent advances that could help overcome them. In total, three key areas for improvement are identified: Quality by Design (QbD) implementation, integration of upstream and downstream technologies, and data and knowledge management. First, the challenges to QbD implementation are explored. Specifically, process control, process analytical technology (PAT), critical process parameter (CPP) identification, and mathematical models for bioprocess control and design are recognized as crucial for successful QbD realizations. Next, the difficulties of end-to-end process integration are examined, with a particular emphasis on downstream processing. Finally, the problem of data and knowledge management and its potential solutions are outlined where ontologies and data standards are pointed out as key drivers of progress.

New high-throughput screening method for Chinese hamster ovary cell lines expressing low reduced monoclonal antibody levels: application of a system controlling the gas phase over cell lysates in miniature bioreactors and facilitating multiple sample setup

Interchain disulfide bonds in monoclonal antibodies may be reduced during large-scale mAb production using Chinese hamster ovary (CHO) cells. This reaction lowers the mAb product yield and purity; however, it may be prevented by screening cell lines that are unsusceptible to reduction and using them in mAb production. Antibody reduction susceptibility may be cell line-dependent. To the best of our knowledge, however, an efficient method of screening reduction-unsusceptible CHO cell lines has not been previously reported. Here, we report a novel screening method that can simultaneously detect and identify mAb reduction susceptibility in lysates containing ≤ 48 CHO cell lines. This evaluation system was equally effective and generated similar results at all culture scales, including 250 mL, 3 L, and 1000 L. Furthermore, we discovered that reduction-susceptible cell lines contained higher total intracellular nicotinamide adenine dinucleotide phosphate (NADPH) and NADP+ concentrations than reduction-unsusceptible cell lines, regardless of whether they expressed immunoglobulin (Ig)G4 or IgG1. NADPH or NADP+ supplementation in the lysate of reduction-unsusceptible cells resulted in mAb reduction. Application of the innovative CHO cell line screening approach could mitigate or prevent reductions in large-scale mAb generation from CHO cells.

An assessment of the impact of Raman based glucose feedback control on CHO cell bioreactor process development

Process analytical technology (PAT) tools such as Raman Spectroscopy have become established tools for real time measurement of CHO cell bioreactor process variables and are aligned with the QbD approach to manufacturing. These tools can have a significant impact on process development if adopted early, creating an end-to-end PAT/QbD focused process. This study assessed the impact of Raman based feedback control on early and late phase development bioreactors by using a Raman based PLS model and PAT management system to control glucose in two CHO cell line bioreactor processes. The impact was then compared to bioreactor processes which used manual bolus fed methods for glucose feed delivery. Process improvements were observed in terms of overall bioreactor health, product output and product quality. Raman controlled batches for Cell Line 1 showed a reduction in glycation of 43.4% and 57.9%, respectively. Cell Line 2 batches with Raman based feedback control showed an improved growth profile with higher VCD and viability and a resulting 25% increase in overall product titer with an improved glycation profile. The results presented here demonstrate that Raman spectroscopy can be used in both early and late-stage process development and design for consistent and controlled glucose feed delivery.

Isolation of antibody by polymer microspheres embedded with E. coli displaying IgG-binding domain

Antibody purification is an important aspect of quality and cost control in the production process of antibody drugs. In this study, modified E. coli was embedded into polymer microspheres (polyvinyl alcohol/alginate) for antibody separation and the IgG binding domain was displayed on the surface of E. coli. The results showed that ZZ protein (Fc binding domain of the antibody) was successfully displayed on the surface of E. coli and was embedded in polyvinyl alcohol/alginate microspheres. In addition, it has excellent specific adsorption capacity for antibodies, with a maximum adsorption capacity of 35.74 mg/g (wet microspheres). Through the adsorption isotherm and adsorption kinetics simulation, the adsorption of IgG on the microsphere matrix conforms to the Langmuir model and follows the pseudo-first-order kinetic equation. The microsphere matrix can undergo saturation adsorption at pH 7.2 and desorption at around pH 3.0. Desorption characteristics are consistent with those of rProtein A Sepharose FF®. After five cycles of the adsorption-desorption processes, the IgG adsorption capacity remains above 80%. Using polymer microspheres to separate antibodies from mouse ascites, the antibody purity reached 86.7% and the yield was 83.5%. These results provide an alternative to protein A matrix with low-cost, fast preparation and moderate efficiency.

Efficient separation of IgG from IgM antibodies via conjugated surfactant micelles

Immunoglobulin-G (IgG) (∼150 kDa) antibodies confer longer term immunity against bacterial or viral infections than the heavier IgM's (∼900 kDa), which are generally detectable in blood circulation in response to more recently acquired infections. There may be, however, a time overlap, which is problematic for diagnostic purposes, in the interests of which it is essential to separate IgM's from IgG's. We describe a purification platform, functioning at pH 6.5, containing Tween-20, or Brij-O20, non-ionic detergent micelles, mixed with the sugar-rich detergent dodecyl maltoside (DDM), amino acid monomer tyrosine (Tyr), and conjugated by the amphiphilic complex [(bathophenanthroline)₃: Fe²⁺]. Using conjugated Brij-O20 micelles, with input molar ratio IgG: IgM 9:1, IgG is recovered at 10 °C with 85-90% yield, (by SDS-PAGE densitometry) and ≥95% purity (also by SDS-PAGE), while IgM's are recovered at lower yields (28-34%) and contain small amounts of co-extracted IgG's. Addition of E. coli lysate as an artificial contamination background does not reduce the yield or purity of the recovered IgG. Tween-20/DDM/Tyr micelles lead to IgG purity ≥95% similar to that of Brij-O20, but with lower process yields (64-70%, by densitometry). Chromatographic separation with Protein A or Protein G resins leads to yields comparable to those obtained with Brij-O20 micelles, but with lower purity.

Autophagy and Breast Cancer: Connected in Growth, Progression, and Therapy

Despite an increase in the incidence of breast cancer worldwide, overall prognosis has been consistently improving owing to the development of multiple targeted therapies and novel combination regimens including endocrine therapies, aromatase inhibitors, Her2-targeted therapies, and cdk4/6 inhibitors. Immunotherapy is also being actively examined for some breast cancer subtypes. This overall positive outlook is marred by the development of resistance or reduced efficacy of the drug combinations, but the underlying mechanisms are somewhat unclear. It is interesting to note that cancer cells quickly adapt and evade most therapies by activating autophagy, a catabolic process designed to recycle damaged cellular components and provide energy. In this review, we discuss the role of autophagy and autophagy-associated proteins in breast cancer growth, drug sensitivity, tumor dormancy, stemness, and recurrence. We further explore how autophagy intersects and reduces the efficacy of endocrine therapies, targeted therapies, radiotherapy, chemotherapies as well as immunotherapy via modulating various intermediate proteins, miRs, and lncRNAs. Lastly, the potential application of autophagy inhibitors and bioactive molecules to improve the anticancer effects of drugs by circumventing the cytoprotective autophagy is discussed.

Methods for addressing host cell protein impurities in biopharmaceutical product development

The high demand for monoclonal antibody (mAb) therapeutics in recent years has resulted in significant efforts to improve their costly manufacturing process. The high cost of manufacturing mAbs derives mainly from the purification process, which contributes to 50%-80% of the total manufacturing cost. One of the main challenges facing industry at the purification stage is the clearance of host cell proteins (HCPs) that are produced and often co-purified with the desired mAb product. One of the issues HCPs can cause is the degradation of the final mAb protein product. In this review, techniques are considered that can be used at different stages (upstream and downstream) of mAb manufacture to improve HCP clearance. In addition to established techniques, many new approaches for HCP removal are discussed that have the potential to replace current methods for improving HCP reduction and thereby the quality and stability of the final mAb product.

Selective and High-Capacity Binding of Immunoglobulin G to Zirconia Nanoparticles Modified with Phosphate Groups

High-performance and cost-effective purification is necessary for the development of antibody drugs. This study found that nanoparticles of zirconia modified with phosphate groups selectively adsorb immunoglobulin G (IgG) antibodies against serum proteins with high adsorption capacity. The IgG antibodies collected from the zirconia nanoparticle surfaces retain their molecular conformation. Importantly, zirconia nanoparticles have the highest affinity for human IgG antibodies among tested mammalian IgG antibodies. The affinity for human IgG subclasses is in the order IgG3 > IgG1 > IgG2, which contrasts with a conventional ligand (Protein A) that has a lower affinity for IgG3. Because zirconia nanoparticles are chemically and mechanically stable, they can be utilized for the purification of antibody drugs not only in batch methods but also in chromatography as a process upstream or downstream of Protein A chromatography and even as an alternative process.

Evaluation of preferred binding regions on ubiquitin and IgG1 FC for interacting with multimodal cation exchange resins using DEPC labeling/mass spectrometry

There is significant interest in identifying the preferred binding domains of biological products to various chromatographic materials. In this work, we develop a biophysical technique that uses diethyl pyrocarbonate (DEPC) based covalent labeling in concert with enzymatic digestion and mass spectrometry to identify the binding patches for proteins bound to commercially available multimodal (MM) cation exchange chromatography resins. The technique compares the changes in covalent labeling of the protein in solution and in the bound state and uses the differences in this labeling to identify residues that are sterically shielded upon resin binding and, therefore, potentially involved in the resin binding process. Importantly, this approach enables the labeling of many amino acids and can be carried out over a pH range of 5.5-7.5, thus enabling the protein surface mapping at conditions of interest in MM cation exchange systems. The protocol is first developed using the model protein ubiquitin and the results indicate that lysine residues located on the front face of the protein show dramatic changes in DEPC labeling while residues present on other regions have minimal or no reductions. This indicates that the front face of ubiquitin is likely involved in resin binding. In addition, surface property maps indicate that the hypothesized front face binding region consists of overlapping positively charged and hydrophobic patches. The technique is then employed with an IgG1 F_C and the results indicate that residues on the C_H 2-C_H 3 interface and the hinge are significantly sterically shielded upon binding to the resin. Further, these regions are again associated with significant overlap of positively charged and hydrophobic patches. On the other hand, while, residues on the C_H 2 and the front face of the IgG1 F_C also exhibited some changes in DEPC labeling upon binding, these regions have less distinct charged and hydrophobic patches. Importantly, the hypothesized binding patches identified for both ubiquitin and F_C using this approach are shown to be consistent with previously reported NMR studies. In contrast to NMR, this new approach enables the identification of preferred binding regions without the need for isotopically labeled proteins or chemical shift assignments. The technique developed in this work sets the stage for the evaluation of the binding domains of a wide range of biological products to chromatographic surfaces, with important implications for designing biomolecules with improved biomanufacturability properties.

Ionic-liquid-based approaches to improve biopharmaceuticals downstream processing and formulation

The emergence of biopharmaceuticals, including proteins, nucleic acids, peptides, and vaccines, revolutionized the medical field, contributing to significant advances in the prophylaxis and treatment of chronic and life-threatening diseases. However, biopharmaceuticals manufacturing involves a set of complex upstream and downstream processes, which considerably impact their cost. In particular, despite the efforts made in the last decades to improve the existing technologies, downstream processing still accounts for more than 80% of the total biopharmaceutical production cost. On the other hand, the formulation of biological products must ensure they maintain their therapeutic performance and long-term stability, while preserving their physical and chemical structure. Ionic-liquid (IL)-based approaches arose as a promise alternative, showing the potential to be used in downstream processing to provide increased purity and recovery yield, as well as excipients for the development of stable biopharmaceutical formulations. This manuscript reviews the most important progress achieved in both fields. The work developed is critically discussed and complemented with a SWOT analysis.

Development of an indirect competitive ELISA method based on ORF2 detecting the antibodies of novel goose astrovirus

Goose astrovirus (GAstV) characterized by articular and visceral gout, is an emerging pathogen with a wide distribution on mainland China, leading to serious economic losses in the goose-raising industry. Because vaccines to prevent GAstV infections are not available currently, early diagnosis is critical when treating symptomatic geese and in preventing GAstV transmission. In this context, a highly sensitive indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a monoclonal antibody (mAb) to detect GAstV-specific antibodies from geese was developed, and the detections were optimized. A series of experiments proved that the ic-ELISA shows excellent diagnostic performance and discriminatory power with high sensitivity and specificity. The ic-ELISA for GAstV detection was applied on 67 field serum samples, and comparing the detection results with the virus neutralization test verified the accuracy of the ic-ELISA. The correlation coefficient between the ic-ELISA and the virus neutralization test was 80%, demonstrating the proposed ic-ELISA method could be a useful and effective tool for the diagnostic, serological epidemiological investigation and immune monitoring of the GAstV in goose-producing regions.

A multiscale modeling method for therapeutic antibodies in ion exchange chromatography

The development of biopharmaceutical downstream processes relies on exhaustive experimental studies. The root cause is the poorly understood relationship between the protein structure of monoclonal antibodies (mAbs) and their macroscopic process behavior. Especially the development of preparative chromatography processes is challenged by the increasing structural complexity of novel antibody formats and accelerated development timelines. This study introduces a multiscale in silico model consisting of homology modeling, quantitative structure-property relationships (QSPR), and mechanistic chromatography modeling leading from the amino acid sequence of a mAb to the digital representation of its cation exchange chromatography (CEX) process. The model leverages the mAbs' structural characteristics and experimental data of a diverse set of 21 therapeutic antibodies to predict elution profiles of two mAbs that were removed from the training data set. QSPR modeling identified mAb-specific protein descriptors relevant for the prediction of the thermodynamic equilibrium and the stoichiometric coefficient of the adsorption reaction. The consideration of two discrete conformational states of IgG4 mAbs enabled prediction of split-peak elution profiles. Starting from the sequence, the presented multiscale model allows in silico development of chromatography processes before protein material is available for experimental studies.

A synthetic transcription platform for programmable gene expression in mammalian cells

Precise, scalable, and sustainable control of genetic and cellular activities in mammalian cells is key to developing precision therapeutics and smart biomanufacturing. Here we create a highly tunable, modular, versatile CRISPR-based synthetic transcription system for the programmable control of gene expression and cellular phenotypes in mammalian cells. Genetic circuits consisting of well-characterized libraries of guide RNAs, binding motifs of synthetic operators, transcriptional activators, and additional genetic regulatory elements express mammalian genes in a highly predictable and tunable manner. We demonstrate the programmable control of reporter genes episomally and chromosomally, with up to 25-fold more activity than seen with the EF1α promoter, in multiple cell types. We use these circuits to program the secretion of human monoclonal antibodies and to control T-cell effector function marked by interferon-γ production. Antibody titers and interferon-γ concentrations significantly correlate with synthetic promoter strengths, providing a platform for programming gene expression and cellular function in diverse applications.

Biosimilars: Science, Implications, and Potential Outlooks in the Middle East and Africa

Biosimilars are biological products that efficiently replicate the function of the originator products. They have changed the prognosis of millions of patients with many serious conditions. The main engine beyond their development is to bring competition into the marketplace, accordingly further the healthcare systems' sustainability. Furthermore, by lowering financial obstacles to biological treatments, biosimilars play a critical role in budgetary redistribution and, hence, promote better allocation of scarce healthcare resources. Today, biosimilars have become a substantial component of effective biological therapies anywhere in the world. Alike, most Middle East and African countries are encouraging the domestic biosimilars industry, and the whole region is aware of the biosimilars' importance. However, constraints to increasing biosimilars uptake should be addressed.

Factors affecting robustness of anion exchange chromatography: Selective retention of minute virus of mice using membrane media

Mobile and stationary phase factors were investigated in order to identify conditions for effective capture of minute virus of mice (MVM), a potential adventitious contaminant in biomanufacturing, using anion exchange membrane chromatography (AEX). The initial study was conducted for Membrane A for a range of feed conditions using bovine serum albumin (BSA) as a model protein mimicking acidic host-cell proteins (HCPs) competitive for virus binding. The effects of pH (6-8), salt concentration (0-150 mM NaCl) and level of BSA (0-10 g/L) were systematically investigated. It was found that higher BSA concentration has the most negative impact on MVM binding followed by the increased conductivity of the feed solution. The effect of pH on MVM binding is also detected but has a less impact compared to other two factors in the range of feed conditions investigated. In addition to Membrane A, three other AEX membranes (Membrane B, C and D) were investigated for MVM binding at a selected feed condition. Based on properties of the membranes investigated, it was found that ligand charge density has the most significant impact on MVM binding performance of AEX membranes from stationary phase perspective.

Application of advanced machine learning algorithms for anomaly detection and quantitative prediction in protein A chromatography

Protein A capture chromatography, which forms the core of the mAb purification platform, demands cautious use and maximum resin utilization due to high cost associated with resin. In this paper, we propose an application of advanced machine learning (ML) algorithms to address two most crucial objectives of column integrity breach and yield prediction for resin cycling study of protein A chromatography. Two approaches have been considered to detect anomalies in case of column integrity breach. The first approach utilized the traditional Principal Component Analysis (PCA) method for dimensionality reduction followed by anomaly detection using Isolation Forest (IF) algorithm. The second approach involved the application of deep learning neural network based Long Short Term Memory autoencoder (LSTM AE). Both the algorithms could successfully predict the column integrity failure 4 cycles ahead of the actual cycle. In the case of prediction of percentage yield decay, a partial least squares-artificial neural network (PLS-ANN) augmented model was utilized and compared with the traditional PLS regression model. The developed PLS-ANN model with higher R² and lower RMSE values of 0.96 and 0.014 respectively could outperform the classical PLS model with lower R² and RMSE values of 0.88 and 0.028, resulting in more accurate yield prediction. The developed ML algorithms for both case studies could not only successfully forecast anomalies by detecting subtle changes in column packing quality and thereby facilitate real time control decisions for preventive measures, a prerequisite for continuous manufacturing, but also demonstrated the ability to predict complex yield decay behaviour for protein A chromatography. As biopharmaceutical manufacturing adopts continuous processing, copious amount of data will be generated from the process and analytical equipment on the manufacturing floor, and the proposed advanced ML algorithms have significant potential in dealing with nonlinearities of the different unit operations simultaneously and facilitate real-time control decision making.

Monoclonal Antibodies: A Therapeutic Option for the Treatment of Ophthalmic Diseases of the Eye Posterior Segment

The eye is an organ that allows us to observe the outside world. Pathologies of the eye's posterior segment, such as glaucoma, macular degeneration, diabetic retinopathy, uveitis, and retinoblastoma, cause vision loss. Traditional treatments consist of applying topical medications that do not penetrate properly or using high doses that generate adverse effects. Different laser surgeries stop the pathology's progression but do not allow visual improvement. So, an alternative is to use monoclonal antibodies, proteins produced by different processes that selectively bind to metabolites associated with diseases, reducing the adverse effects of traditional treatments and improving the application of the drug in the area. The two main molecular targets are TNF (adalimumab, infliximab, and certolizumab pegol) and VEGF (bevacizumab and ranibizumab); other possibilities are under investigation.

Comparison of originator and biosimilar monoclonal antibodies using HRMS, Fc affinity chromatography, and 2D-HPLC

Due to the complex manufacturing process of therapeutic monoclonal antibodies, it is hardly possible to produce an identical copy of the original product (originator). Consequently, follow-on products (biosimilars) must demonstrate their efficacy being similar to the originator in terms of structure and function. During this process, a variety of analytical methods are required for this purpose. This study focuses on three particularly relevant analytical techniques: high-resolution mass spectrometry, fragment crystallisable (Fc) affinity chromatography, and two-dimensional peptide mapping. Each analytical method proved able to identify specific differences between originator and biosimilar. High-resolution mass spectrometry was used to characterize the glycan pattern. It was shown that a trastuzumab biosimilar did not have the G0:G0F sugar modification identified in the originator. The application of affinity chromatography to rituximab showed that originator and biosimilar interacted differently with the immobilized Fc receptor. Furthermore, 2D-HPLC peptide mapping demonstrated the influence of orthogonality of separation dimensions, leading to differentiation of a rituximab originator and biosimilar.

Study on antibody adsorption and elution performance of carboxyl and hydrophobic groups on mixed-mode ligands

Molecular interactions between ligands and target biomolecules are crucial in the development of chromatographic techniques for the separation and purification of biotherapeutics. In this study, the role of functional moieties on a mixed-mode ligand (phenylalanine-tyrosine-glutamate-5-aminobenzimidazole) for human immunoglobulin G purification was investigated and a detailed mechanism was discussed. A similar ligand with glutamic acid substituted by glutamine (phenylalanine-tyrosine-glutamine-5-aminobenzimidazole) together with other resins including a commercial resin (CM Bestarose Fast Flow), phenylalanine-tyrosine-glutamate, glutamate-5-aminobenzimidazole, and 5-aminobenzimidazole resins were prepared for comparison. Molecular dynamics simulation and experimental studies were used to analyze the difference between these ligands. The results showed that the carboxyl group of phenylalanine-tyrosine-glutamate-5-aminobenzimidazole contributed 70% of the electrostatic interaction during human immunoglobulin G binding, and 5-aminobenzimidazole provided electrostatic repulsion for desorption, which showed low selectivity and binding capacities at pH 4.0 (dynamic binding capacities at 10% breakthrough of human immunoglobulin G = 1.0 mg/ml resin, dynamic binding capacities at 10% breakthrough of human serum albumin = 1.2 mg/ml resin) when used as an individual resin ligand. The results showed in this study demonstrated that it is possible to achieve optimal antibody separation and purification through reasonable ligand design by understanding the performance of key functional moieties in binding and elution processes.

Electrically Switchable Polymer Brushes for Protein Capture and Release in Biological Environments

Interfaces functionalized with polymers are known for providing excellent resistance towards biomolecular adsorption and for their ability to bind high amounts of protein while preserving their structure. However, making an interface that switches between these two states has proven challenging and concepts to date rely on changes in the physiochemical environment, which is static in biological systems. Here we present the first interface that can be electrically switched between a high‐capacity (>1 μg cm⁻²) multilayer protein binding state and a completely non‐fouling state (no detectable adsorption). Switching is possible over multiple cycles without any regeneration. Importantly, switching works even when the interface is in direct contact with biological fluids and a buffered environment. The technology offers many applications such as zero fouling on demand, patterning or separation of proteins as well as controlled release of biologics in a physiological environment, showing high potential for future drug delivery in vivo.

Recent advances in protein-imprinted polymers: synthesis, applications and challenges

The molecular imprinting technique (MIT), also described as the "lock to key" method, has been demonstrated as an effective tool for the creation of synthetic polymers with antibody-like sites to specifically recognize target molecules. To date, most successful molecular imprinting researches were limited to small molecules (<1500 Da); biomacromolecule (especially protein) imprinting remains a serious challenge due to their large size, chemical and structural complexity, and environmental instability. Nevertheless, protein imprinting has achieved some significant breakthroughs in imprinting methods and applications over the past decade. Some special protein-imprinted materials with outstanding properties have been developed and exhibited excellent potential in several advanced fields such as separation and purification, proteomics, biomarker detection, bioimaging and therapy. In this review, we critically and comprehensively surveyed the recent advances in protein imprinting, particularly emphasizing the significant progress in imprinting methods and highlighted applications. Finally, we summarize the major challenges remaining in protein imprinting and propose its development direction in the near future.

Comprehensive Assessment of Host Cell Protein Expression after Extended Culture and Bioreactor Production of CHO Cell Lines

The biomanufacturing industry is advancing toward continuous processes that will involve longer culture durations and older cell ages. These upstream trends may bring unforeseen challenges for downstream purification due to fluctuations in host cell protein (HCP) levels. To understand the extent of HCP expression instability exhibited by Chinese hamster ovary (CHO) cells over these time scales, an industry-wide consortium collaborated to develop a study to characterize age-dependent changes in HCP levels across 30, 60, and 90 cell doublings, representing a period of approximately 60 days. A monoclonal antibody (mAb)-producing cell line with bulk productivity up to 3 g/L in a bioreactor was aged in parallel with its parental CHO-K1 host. Subsequently, both cell types at each age were cultivated in an automated bioreactor system to generate harvested cell culture fluid (HCCF) for HCP analysis. More than 1,500 HCPs were quantified using complementary proteomic techniques, two-dimensional electrophoresis (2DE) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). While up to 13% of proteins showed variable expression with age, more changes were observed when comparing between the two cell lines with up to 47% of HCPs differentially expressed. A small subset (50 HCPs) with age-dependent expression were previously reported to be problematic as high-risk and/or difficult-to-remove impurities; however, the vast majority of these were down-regulated with age. Our findings suggest that HCP expression changes over this time scale may not be as dramatic and pose as great of a challenge to downstream processing as originally expected but that monitoring of variably expressed problematic HCPs remains critical. This article is protected by copyright. All rights reserved.

Affinity Sedimentation and Magnetic Separation With Plant-Made Immunosorbent Nanoparticles for Therapeutic Protein Purification

The virus-based immunosorbent nanoparticle is a nascent technology being developed to serve as a simple and efficacious agent in biosensing and therapeutic antibody purification. There has been particular emphasis on the use of plant virions as immunosorbent nanoparticle chassis for their diverse morphologies and accessible, high yield manufacturing via plant cultivation. To date, studies in this area have focused on proof-of-concept immunosorbent functionality in biosensing and purification contexts. Here we consolidate a previously reported pro-vector system into a single Agrobacterium tumefaciens vector to investigate and expand the utility of virus-based immunosorbent nanoparticle technology for therapeutic protein purification. We demonstrate the use of this technology for Fc-fusion protein purification, characterize key nanomaterial properties including binding capacity, stability, reusability, and particle integrity, and present an optimized processing scheme with reduced complexity and increased purity. Furthermore, we present a coupling of virus-based immunosorbent nanoparticles with magnetic particles as a strategy to overcome limitations of the immunosorbent nanoparticle sedimentation-based affinity capture methodology. We report magnetic separation results which exceed the binding capacity reported for current industry standards by an order of magnitude.

Towards continuous mAb purification: clearance of host cell proteins from CHO cell culture harvests via "flow-through affinity chromatography" using peptide-based adsorbents

The growth of advanced analytics in manufacturing monoclonal antibodies (mAb) has highlighted the challenges associated with the clearance of host cell proteins (HCPs). Of special concern is the removal of "persistent" HCPs, including immunogenic and mAb-degrading proteins, that co-elute from the Protein A resin and can escape the polishing steps. Responding to this challenge, we introduced an ensemble of peptide ligands that target the HCPs in Chinese hamster ovary (CHO) cell culture fluids and enable mAb purification via flow-through affinity chromatography. This work describes their integration into LigaGuardTM, an affinity adsorbent featuring an equilibrium binding capacity of ~30 mg of HCPs per mL of resin as well as dynamic capacities up to 16 and 22 mg/mL at 1- and 2-minute residence times, respectively. When evaluated against cell culture harvests with different mAb and HCP titers and properties, LigaGuardTM afforded high HCP clearance, with logarithmic removal values (LRVs) up to 1.5, and mAb yield above 90%. Proteomic analysis of the effluents confirmed the removal of high-risk HCPs, including cathepsins, histones, glutathione-S transferase, and lipoprotein lipases. Finally, combining LigaGuardTM for HCP removal with affinity adsorbents for product capture afforded a global mAb yield of 85%, and HCP and DNA LRVs > 4. This article is protected by copyright. All rights reserved.