Glycosylation is one of the most common post-translational modifications in mammalian-expressed biologics, and is considered to be a critical quality attribute of therapeutic glycoproteins. Due to its biological relevance, physiochemical assessment on the glycosylation profile is always important to the success of a drug development initiative. This article describes the combination of experimental design and machine learning techniques applied to characterize and optimize a conventional, non-derivatized glycoprofiling method on glycans derived from a human immunoglobulin using high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Two independent experimental designs, a 16-run definitive screening design (DSD) and a 28-run central composite design (CCD), were incorporated with a machine learning technique known as “self-validating ensemble modeling (SVEM)” and used to build predictive models for four chromatographic responses. We show that the predictive models created using SVEM on the DSD data reliably predicted the behavior of the chosen responses when applied to CCD validation data. This demonstrates that the DSD is an efficient alternative to the larger, traditional CCD in which the combination of experimental design and machine learning can effectively characterize and optimize analytical methods.
Tag: <span>optimization</span>
Optimal process development creates unit operations that effectively generate, separate, and concentrate a broad array of products. Historically, tangential flow filtration (TFF) process capabilities have been limited by technological and flow restrictions. Recent innovations in TFF module design have dramatically increased the capabilities of TFF to better achieve processing objectives. NCSRT has established a best practices protocol for developing clarification, fractionation, and concentration processes for mammalian, bacteria, yeast, insect, and virus based production systems. This article presents the development platform, supplemented with application-specific expertise…
Today concentrated efforts are underway to improve the bioactivity of therapeutic proteins with the aim of reducing: (i) the number and concentration of the applied doses of the therapeutic protein, (ii) undesired side effects, and (iii) the cost of a therapy. A very promising strategy is to optimise the glycosylation of these biotherapeutics. A novel expression platform, GlycoExpress™, has been developed to produce proteins with fully human glycosylation, optimised sialylation, and improved bioactivity…
Total market share of biopharmaceuticals is estimated to increase from $33 billion now to more than $45 billion in 2007. These numbers are accounted for by the 64 products approved by European and US regulators and some of the 500 products currently under clinical evaluation. More than 2,000 products are in discovery and preclinical development. Monoclonal antibodies (MAbs) and recombinant glycoproteins constitute a major part of these new biotech leads. The estimated demands for MAbs alone are more than 6,000 kg per year in 2006. Currently, 16 MAbs are licensed by the U.S. Food and Drug Administration (FDA) for pharmaceutical use and more than 130 are in clinical trials. This fast-growing class of biotherapeutics is expected to reach worldwide sales of more than $15 billion per year in 2008. In the coming years, mammalian cell culture technology will remain the production system of choice for MAbs and other recombinant glycoproteins. Therefore, efficient, cost-effective production systems need to be in place to meet the demands…
Proteins and their promise for revolutionizing drug discovery have come virtually full circle in just a few decades. The advent of genetic engineering and the emergence of early recombinant proteins such as insulin and interferon dramatically boosted the perceived value of proteins in pharmaceutical research and of protein drugs in particular. Although the lights dimmed somewhat on the promise of therapeutic proteins in subsequent years, more recent times have seen a resurgence of interest in proteins, particularly monoclonal antibodies. Perhaps most telling has been the dawn of the post-genomic era, which has cast a bright spotlight on proteins, long respected as the work-horses of the cell, for their usefulness in exploring cell function, unraveling biochemical pathways, understanding disease, and for their massive value as novel drug targets…
A growing number of separations’ scientists and process developers are looking beyond protein A sorbents for capture and initial purification of monoclonal antibodies. A variety of strategic and operational goals have prompted examination of alternative immunoglobulin-selective sorbents. Most broadly, many workers wish to eliminate design considerations associated with leached protein A. Also cited is a preference for sorbents that can withstand stringent cleanup using 1 M sodium hydroxide. In some applications, it is desirable to avoid the low-pH elution conditions typically employed with protein A sorbents — conditions that can foster aggregate formation. In still other cases, the target antibody may bind poorly to protein A. Finally, there may be interest in evaluation of immunoglobulin-selective sorbents less costly than protein A sorbents…
Single-use, disposable components offer many advantages in the manufacturing of biologics. They are clean and ready to use when supplied, which obviates the need for sterilization and decreases the requirement for services such as water for irrigation (WFI) systems and steam generators. Disposable components are not used for subsequent operations, eliminating the chance of cross contamination between process runs. Long lead times for equipment installation can be avoided because the need for stainless steel equipment is reduced or eliminated. Systems are less complex, therefore engineering requirements are also reduced. There is no need for clean-in-place (CIP) or steam-in-place (SIP) operations, along with the associated piping, valves, controls, or pressure rating of vessels. Moreover, the use of disposable components reduces the complexity of validation…
The human protein kinase superfamily is one of the largest and most important families of enzymes. More than 500 distinct kinases, classified in about 20 families on the basis of their primary structure similarity, have been identified to date. Protein kinases regulate a variety of biochemical pathways in cells through phosphotransfer reactions, playing pivotal roles in most signaling and regulatory processes, such as gene expression, proliferation, cell motility, and angiogenesis. Deregulation and/or mutational modification of protein kinase activity, leading to aberrant protein phosphorylation, is implicated in a variety of diseases, particularly cancer, making protein kinases important drug targets. A number of specific protein kinase inhibitors has been developed recently and more than 30 compounds are currently in clinical development or on the market. Many of these inhibitors are small-molecule compounds that compete with ATP for the highly conserved ATP binding site of the kinases. The development of highly selective and potent ATP-competitive inhibitors is driven by structure-activity relationship (SAR) studies, with X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy playing an important role in the understanding of the mechanism of inhibitor binding to the active or inactive forms of protein kinases…
Process development is an investment. As with a personal retirement plan, the importance of making the investment is not in question, yet strategies for when, how much, and where to invest in process development vary significantly from company to company. For a personal retirement plan, the answers to these questions are straightforward: invest as early as you can and as much as you can, and take less risk the closer you get to retirement. This would also be sound advice for investing in process development (substituting “BLA filing” for “retirement”) were it not for two complicating factors. First, the majority of biotherapeutics that enter the clinic fail to make it to the market. This makes a large, early investment in process development less attractive. Second, there is extreme pressure to get into the clinic, and subsequently onto the market, as quickly as possible, minimizing the time available for process development…