Chromatography

challenges with exosome therapy

eBook: Challenges in Industrial Process Development of Exosome-Based Therapies: Characterizing and Managing Diversity

The traditional classification of extracellular vesicles (EVs) includes three types: exosomes, microvesicles, and apoptotic vesicles. Each type arises from a distinct origin and exhibits distinct characteristics. The problem is that their size ranges overlap and that the major surface proteins presented by exosomes also are present on the surfaces of microvesicles and apoptotic bodies. This makes it a challenge for process developers to identify the vesicle fraction that best serves a particular exosome therapy. Anion-exchange chromatography (AEC) can fractionate EVs…

Discover, Develop, Deliver

Astrea Bioseparations is the only adsorbent supplier that can discover new affinity ligands designed to bind selectively to a molecule of interest or specific impurity, develop efficient purification adsorbents and downstream methods, and deliver industrial-scale adsorbents (up to 1,000-L batch sizes) as loose slurry or in good manufacturing practice (GMP)-ready columns. With over 30 years of experience in development of affinity products and design and manufacture of new custom adsorbents, Astrea Bioseparations is a world leader in its field. The…

Reduce Downstream Processing Costs for MAbs By Switching to a Two-Step Platform

Downstream processing operations make up to 80% of the total costs for processing biotherapeutics. Given the current drive to reduce downstream costs, chromatographers and process engineers will need to streamline processes. Herein, we describe the benefits offered by using Tosoh’s two-step process for purifying monoclonal antibodies (MAbs) and compare that method with the standard industrial process. By combining high-performance protein A capture and a single polishing step on salt-tolerant anion-exchange resin, Tosoh’s approach can reduce downstream costs by 45% and…

Capture of CH1-Containing Bispecific Antibodies: Evaluating an Alternative to Protein A

Bispecific antibodies (BsAbs) are designed to recognize and bind two different antigens, in many cases for the purpose of immune effector-cell activation to destroy cancer cells (1). Such BsAbs mediate cell killing by binding simultaneously to an antigen that is overexpressed on tumor cells and to the CD3 receptor, activating cytotoxic T lymphocytes (2). Using proprietary UniRat human heavy-chain technology combined with OmniFlic human fixed–light-chain antibody technology licensed from Ligand Pharmaceuticals, Teneobio has produced several bispecific antibodies, each targeting a…

Dynamic Binding Capacities of Protein A Resins for Antibody Capture: A Comparative Evaluation

The dynamic binding capacity (DBC) of a chromatography resin represents the total amount of target protein that the resin will bind under actual flow conditions before significant breakthrough of unbound protein occurs. This is a useful parameter for predicting what the process performance of a resin will be in actual use. DBC affects the overall amount of resin that can be packed in a given column for a process — and the number of batches that can be processed cost-effectively…

Setting a Cornerstone for Platform Purification of Exosomes

Exosomes are a subject of rapidly growing therapeutic interest in the biopharmaceutical industry for two principal reasons. The first reason is that they are the primary communicators of instructions from source cells to target cells. Exosome surface features define their destination. They recognize complementary features on target cells, dock with them, and deliver their programmed instructions in the form of microRNA. The second reason is that exosomes are immunologically silent. As normal human cell products, and by contrast with gene…

Monoclonal Antibody Aggregate Polish and Viral Clearance Using Hydrophobic-Interaction Chromatography

Hydrophobic Interaction chromatography (HIC) is a powerful polishing tool for the downstream purification and manufacture of biotherapeutics. HIC offers orthogonal selectivity for the clearance of difficult process and product-related impurities such as aggregates, host cell proteins and endogenous and adventitious viruses.  In this study, a family of POROS HIC resins with novel ethyl and benzyl chemistries was used to successfully polish two clinical stage monoclonal antibodies harboring very high levels of product aggregation (>10%). In addition to aggregate removal, viral…

Control of Protein A Column Loading During Continuous Antibody Production: A Technology Overview of Real-Time Titer Measurement Methods

During production of therapeutic antibodies, harvest titer is measured to monitor product mass loaded onto the protein A capture column. This prevents both column underloading (underusing expensive resin) and overloading (wasting product as flow-through (FT)) while allowing for column yield calculations. Batch production yields a single homogenous harvest pool, thus only one titer measurement (along with volume loaded) is sufficient to determine the mass loaded. During continuous production, however, cell-free harvest (permeate) continuously exits a perfusion reactor and loads a…

An Integrated Bioprocess for Antibodies: From Harvest to Purified Bulk in Six Hours

Antibody production platform processes have been widely adopted in biomanufacturing, but many unit operations are not suitable for integration and automation. Here we describe the work of integrating unit operations by transforming a column operation to a more robust cassette format. We have selected a biomolecule-friendly buffer (phosphate) to eliminate, or delay, the performance of a circulating tangential flow ultrafiltration/diafiltration (UF/DF) operation, so the harvest-to-purified-bulk process can be integrated, resulting in a single, direct-flow operation, that reduces the batch process…

Making Downstream Processing Continuous and Robust: A Virtual Roundtable

Current biomanufacturing is driven to pursue continuous processing for cost reduction and increased productivity, especially for monoclonal antibody (MAb) production and manufacturing. Although many technologies are now available and have been implemented in biodevelopment, implementation for large-scale production is still in its infancy. In a lively roundtable discussion at the BPI West conference in Santa Clara, CA (11 March 2019), participants touched on a number of important issues still to be resolved and technologies that are still in need of…