Product Characterization

High-Yield Production of PASylated Human Growth Hormone Using Secretory E. coli Technology

Since the 1985 approval of the first recombinant human growth hormone (hGH, such as Protropin/somatrem human growth hormone from Genentech, now Roche), the number of clinical indications for therapy with hGH has steadily increased (1). That led to a highly successful drug with more than US$3 billion sales in 2011 (2). Even so, hGH shares a common problem with most other first-generation protein therapeutics: a very short plasma half-life of just about two hours in humans. Because such biologics are…

A Powerful Pairing

Biological product and process characterization are not new to this quality by design (QbD) and process analytical technology (PAT) era. In the 1990s we saw the FDA introduce the concept of well-characterized biologics: an acknowledgment that analytical technology had advanced to the point where the bioprocess did not necessarily (or not fully, anyway) define a biopharmaceutical product. That ultimately led to the regulation of some types of products within the United States moving from the purview of FDA’s Center for…

PEGylation of Biologics

In the 1970s, life-science researchers envisioned protein therapeutics as the ultimate targeted therapy. Companies could use them to address genetic deficiencies and cancer, among other disease classes, as well as to nudge the immune system for treating autoimmune disorders. The first therapeutic proteins were derived from animal or microbial cells, so patients launched immune responses to them that could curtail their activity and produce dangerous side effects. PEGylation was initially used to prevent immune responses with such drugs. PEG is…

Stress-Induced Antibody Aggregates

Biomanufacturing of monoclonal antibodies (MAb) involves a number of unit operations, including cell culture in a bioreactor followed by chromatography and filtration. Purification is intended to remove impurities, such as protein aggregates, but some such operations may actually generate protein aggregation (1). Table 1 summarizes potential sources of aggregate formation during biomanufacturing processes. Aggregates are multimers of native, partially denatured, or fully denatured proteins. Their presence in biological formulations can trigger detrimental immunogenic responses upon administration (2). Moreover, aggregates can…

Tunable Half-Life Technology

While a constantly developing market puts increasing pressure on pharmaceutical companies to provide advanced and personalized therapies, the industry is investing heavily in the development of targeted biologics. The aim is often to take new therapeutics through clinical trials and to market as quickly as possible and to develop more novel, tailored drugs. One common challenge for many biologics is their short plasma half-life. That often leads to reduced bioavailability, meaning that an administered drug will clear from a patient’s…

Biophysical Analysis of Living Cells

Adecades-old technology is finally emerging from clinical laboratories and demonstrating its utility in drug discovery and development. Cell therapy researchers bring their laboratory experiences with them as their science is commercialized. And as biopharmaceutical production engineers incorporate quality by design (QbD) and process analytical technology (PAT) into their work, they find that a method for monitoring the state and distribution of living cells can help build valuable upstream process knowledge. In flow cytometry, cells are suspended in fluid to flow…

Prior-Knowledge Assessments

    Process characterization (PC) studies are experiments performed primarily at laboratory scale to demonstrate process robustness and provide data necessary for planning, risk mitigation, and successful execution of process validation (1, 2). These typically involve extensive, multifactorial testing designed to determine the effects of operational parameter perturbations and raw materials on process performance and product quality (1, 2). Product-specific information from development studies may be used to help guide PC study design; however, such information may be limited or…

A Decade of Characterization

    Over the past 10 years, the biopharmaceutical industry has placed increasing pressure on analytical laboratories, whose work is more important to the success of biotherapeutic products than ever before. Nearly concomitant with the appearance of BPI on the scene, the US Food and Drug Administration put forth its final report on the 21st century good manufacturing practice initiative, which in changing how regulators would review product applications, changed how companies must approach them (1). The guiding principles —…

“Hard Cell”: Potency Testing for Cellular Therapy Products

Potency testing is defined in 21 CFR Part 600.3(s) as “the specific ability or capacity of the product, as indicated by appropriate laboratory tests or by adequately controlled clinical data obtained through the administration of the product in the manner intended, to effect a given result” (1). Potency measurement is especially important for complex products such as cellular therapies (CTs). It is considered an essential aspect of the quality-control system for a CT drug substance and drug product. It is…

Recommendations for Cell Banks Used in GXP Assays

Cells and cell-derived reagents form the basis of an operationally challenging class of test methods used in execution of product potency testing (stability and lot release), assessments of pharmacokinetic/ pharmacodynamic (PK/PD) profiles, detection of antidrug antibodies (ADAs) or neutralizing antibodies (NAB), and characterization and comparability testing of biopharmaceutical products. Frequently, cell-based assays provide the only measurement of the tertiary/quaternary structure of each batch of product at the time of lot release and during stability testing to assist in determining product…