Author Archives: David A. Brindley

Scalable Purification of Viral Vectors for Gene Therapy: An Appraisal of Downstream Processing Approaches

Gene therapy is the transfer of genetic material to a patient’s cells to achieve a therapeutic effect. Therapeutic DNA is largely delivered using viral vector systems based on adenoviruses (Ad), adenoassociated viruses (AAV), and lentiviruses (LV). With the application of such viral vectors as clinical therapeutics growing, scalable commercial processes (particularly for purification) are being investigated and optimized to best ensure that critical quality attributes (CQAs) are retained. Herein we review viral vector purification techniques and the effect of different…

Emerging Platform Bioprocesses for Viral Vectors and Gene Therapies

Recent advances in molecular biology are expediting genomic sequencing to underpin precision medicine. Such progress is positioning gene and gene-modified cell therapy on the cusp of an extraordinary revolution in patient care for presently unmet medical needs — and a new therapeutic class that could rival monoclonal antibodies (MAbs) in importance. However, despite substantial strides made in clinical trials, the bioprocessing community is struggling to fulfill growing demands for biomanufacturing capacity to make gene and gene-modified cell therapies — including…

Automation of CAR-T Cell Adoptive Immunotherapy Bioprocessing: Technology Opportunities to Debottleneck Manufacturing

Continued clinical efficacy demonstrations of cell-based immunotherapies (iTx) such as chimeric antigen receptor T cell (CAR-T) therapies has made the prospect increasingly likely of an immunotherapy product achieving conditional market authorization in the short term. For example, Novartis and the University of Pennsylvania’s lead candidate (CTL019) for treating a range of hematological malignancies received breakthrough status from the US Food and Drug Administration (FDA) in 2014, permitting access to an expedited drug development pathway for high unmet medical needs (1).…

Therapeutic Gene Editing: Tools to Facilitate Basic Science or Stimuli for a Paradigm Shift in Biomanufacturing?

Historically, fundamental science and process engineering were separated by distinct vernaculars and a decade or more in the translation pathway of candidate therapeutics from laboratory to bedside (1). This crude metric holds true for the origins of the modern pharmaceutical industry, namely fine chemicals that supported the high-margin small molecules that constitute the majority of the pharmacopoeia even today. But as illustrated by deeply interwoven careers, companies, and technologies — including those related to monoclonal antibodies (MAbs) — that classic…

Decision-Support Tools for Monoclonal Antibody and Cell Therapy Bioprocessing: Current Landscape and Development Opportunities

Industrial-scale manufacturers in a number of fields — from automobiles to biotherapeutics — have long relied on powerful computational and mathematical tools to aid in the scale-up, optimization, quality control, and monitoring of product development (1–5). Typical process pathways are highly multifactorial, with numerous branch points, feedback steps, instrumental attributes, and target parameters. Moreover, margins for error are minimal for most industrial processes, requiring high standards of precision from industrial and operational pathways (6). For those reasons, the complexity of…

Quantitative Risk Assessment of Bioaccumulation Attributable to Extractables and Leachables in Cellular Immunotherapy Biomanufacturing

Precious patient samples, contamination concerns, and limited product purification options have compelled manufacturers of cellular immunotherapies (iTx) such as chimeric antigen receptor T cells (CAR-T) and T-cell receptor (TCR) technologies toward the disposables industry. Such companies are implementing single-use technologies (SUTs) almost exclusively (1). But despite the dominance of disposable bioprocess platforms and their extraordinary growth in the iTx marketplace, researchers have made limited efforts to understand the perennial and critical bioprocessing risks of leachables and extractables. Here we outline…

Extracellular Vesicles Commercial Potential As Byproducts of Cell Manufacturing for Research and Therapeutic Use

Extracellular vesicles (EVs) are emerging as a potential alternative to some stem-cell–derived therapeutics (1, 2). Sometimes called exosomes, they are small, secreted vesicles that can possess similar therapeutic mechanisms to whole cells, possibly representing the active pharmaceutical ingredient. In the past 15 years, academic and industry interest in EVs has exponentially increased as mounting evidence demonstrates their role in physiology and pathology as well as their therapeutic potential. In light of growing efforts in using EVs for research and therapy,…

The Potential Application of Real‑Time Release Testing for the Biomanufacture of Autologous Cell‑Based Immunotherapies

Cell-based immunotherapies (iTx) are emerging as a truly transformative therapeutic modality that is both complementary and convergent with existing regenerative medicine approaches, including gene therapy, cell therapy, and tissue engineering (Figure 1). Critically, iTx offer step-change improvements in efficacy compared with current standards of care (1) for a range of clinical indications and unmet therapeutic needs — particularly oncology. The clear efficacy of iTx is in contrast with some previous regenerative medicine approaches, including early mesenchymal stem cell (MSC) therapies…

Cell Therapy Bioprocessing Technologies and Indicators of Technological Convergence

The cell therapy industry is undergoing a natural evolution from scientific curiosity into a commercially and clinically attractive opportunity (1). This evolution is by no means complete, and growing evidence suggests that its progression is driving significant developments in cell therapy bioprocessing — notably, convergence. Table 1:&#8 194; () Progressively, bioprocessing technologies primarily used in production of noncell-based products are being evaluated for cell therapy bioprocessing applications (2). Consequently, this process of convergence is leading to an increasing proportion of…

Automation of Cell Therapy Biomanufacturing

Biomanufacturing automation is an established mission-critical step in the commercialization pathway for conventional therapeutics, including small molecules and monoclonal antibodies (MAbs) (1). The prospect of a potential biologic progressing into late-stage clinical trials without a robust biomanufacturing strategy to support at least pilot-plant scale bioprocessing is simply unthinkable. Conversely, the cell therapy industry (or at least a significant proportion of it) regard this as a trend that is unlikely to be mirrored as the industry develops. The aim of this…