Downstream Processing

Rethinking Chromatography

Dynamic trends in the biotherapeutic industry are shifting manufacturers towards new modalities and intensified production strategies. This development is supported by ongoing scientific and technical advances in both upstream and downstream processing steps. Downstream processing of new modalities requires chromatography technologies that can handle large, fragile molecules (such as mRNA and viral particles). To maximize speed and productivity, platforms supporting continuous processing will become essential. In this feature, Sartorius discusses current and future concerns for process chromatography operations. They then…

Reducing Cell and Gene Therapy Development Time and Cost with New Purification Strategies

The past 40 years have ushered in the most advanced medicines the world has ever seen, with tremendous improvements in biomanufacturing technologies to enable their development. Advances in production technology have brought significant improvements in upstream productivity, which then caused bottlenecks in downstream processing. Although many bottlenecks have been resolved for most biologics, new modalities such as gene therapies and mRNA vaccines are driving the need for differentiated purification solutions. Meanwhile, pressures to increase efficiency and reduce costs continue to…

Viral Safety of Viral Vectors:
Special Concerns Arise When the Virus Is the Product

As anyone who has focused on host-cell proteins as process contaminants can tell you, trying to purify a specific type of molecule from a large mixture of many similar molecules is like trying to find a few particular needles in a huge pile of varied needles. The same could be said for purifying viral vectors from cell culture fluids. When viruses are the products, unwanted viruses are contaminants that must be separated away — or better yet, prevented from being…

MAb Viral Clearance Studies:
A Substantiated Platform Approach for the IND Stage

Virus removal/inactivation is a major concern in the safety of monoclonal antibodies (MAbs) and other recombinant-protein drugs. Some methods (such as nanofiltration and low-pH inactivation) have been demonstrated repeatedly by the industry to be reliable for most viruses, with >4 log10 removal. Based on my company’s virus-removal experiences with its MAb downstream-process platform, we propose a “bracketing method” — testing only samples that lie at the extremes of a design space — to prove proactively that small differences in operating…

Risk Determination of Potential Mycotoxin Exposure to Patients: Testing Recombinant Human Factor VII from Transgenic Rabbits

Sevenfact eptacog beta is a new recombinant human factor VIIa (rFVIIa) developed by LFB SA in Les Ulis, France, as a bypassing agent (BPA) for treatment and control of bleeding in people with hemophilia A and B and inhibitors (1, 2). The product was approved for use in adults and adolescents by the US Food and Drug Administration (FDA) in April 2020 (3). It is expressed in the milk of transgenic rabbits and purified through a multistep process using both…

Comparing Single-Use Multicycle Cake Filtration with Depth Filtration: Eliminating the Downstream Bottleneck

Over the past few decades, single-use (SU) technology has increased bioproduction efficiency significantly, especially with the introduction of disposable bioreactors in upstream processing. To keep pace with major developments and increases in upstream capacity, downstream processes also must increase capacity and efficiency. However, cell harvesting and downstream processing continue to present bottlenecks in manufacturing (1). Typical clarification processes are composed of primary and secondary clarification steps, such as centrifugation followed by depth filtration, respectively (1). Two sets of SU depth…

Advanced Data-Driven Modeling for Biopharmaceutical Purification Processes

Purification is an essential process in biopharmaceutical manufacturing that separates a therapeutic protein in its active form from impurities. A typical purification process consists of several chromatography unit operations, and each unit operation comprises multiple phases. During the operation of each step, continuous (time-series data per parameter for each batch) and batch data (one data point per parameter for each batch) are generated by in-line sensors installed in chromatography skids on the production floor and with at-line/off-line in-process samples, respectively.…

Development of a Universal Preparative Anion-Exchange Method to Purify Oligonucleotides

Oligonucleotide-based therapeutics have been studied over recent decades, and their promise as a new drug modality is now being realized. The growing interest in oligonucleotides is driven by their high potential for treating different medical conditions, the growing number of oligonucleotide drugs approved by the US Food and Drug Administration (FDA), an increased focus on personalized medicines, the development of therapies for rare diseases, and the wide adoption of nucleotide-based COVID-19 vaccines. Oligonucleotides are short, linear sequences of DNA or…

The Effect of Benzonase Endonuclease Addition to Purification of Sabin Poliovirus Type 3

During production of vaccines and viral vectors, the size and quantity of extracellular nucleic acids must be reduced using endonuclease enzymes. Merck/MilliporeSigma’s proprietary Benzonase endonuclease is a genetically engineered nuclease derived from the Gram-negative bacteria Serratia marcescens. It attacks and degrades all forms of DNA and RNA. It is manufactured under good manufacturing practice (GMP) conditions and has a drug master file (MDF) in place with the US Food and Drug Administration (FDA), which can be cited in regulatory filings.…

New Antibody Formats on the Block:
More Complex Modalities Demand Innovation in Manufacturing and Purification

Some of the latest, most promising therapeutic developments in the biologics industry use antibody fragments — either separate functional subunits of antibodies or recombinant molecules that are composed of immunoglobulin domains. The most popular fragments are antigen-binding fragments (Fabs), variable single-chain fragments (scFvs), diabodies, and nanobodies. Such molecules raise several advantages over their parent molecules for upstream production but pose several challenges for downstream purification. To facilitate antibody-fragment capture, Tosoh Bioscience has developed Toyopearl AF-rProtein L-650F resin. Its ligand uses…