Approaches to Quality Risk Management When Using Single-Use Systems in the Manufacture of Biologics

Drug product Formulation and Fill/Finish Manufacturing Process Considerations for AAV-Based Genomic Medicines

Adeno-associated viruses (AAVs) have become the delivery medium of choice for a variety of genomic medicine applications i.e., gene therapy, gene editing/regulation, and ex-vivo cell therapy. AAVs are protein-DNA complexes which have unique stability characteristics that are susceptible to various stress exposure conditions commonly seen in the drug product (DP) life cycle. This review takes a comprehensive look at AAV DP formulation and process development considerations that could impact critical quality attributes (CQAs) during manufacturing, packaging, shipping, and clinical use. Additional aspects related to AAV development reviewed herein are: (1) Different AAV serotypes with unique protein sequences and charge characteristics potentially leading to discrete stability profiles; (2) Manufacturing process challenges and optimization efforts to improve yield, recovery and purity especially during early development activities; and (3) Defining and identifying CQAs with analytical methods which are constantly evolving and present unique characterization challenges for AAV-based products.

Risk assessment for biopharmaceutical single-use manufacturing: A case study of upstream continuous processing

In the current transition to intensified upstream processing, the risks of adopting traditional single-use systems for high-titer, long-duration perfusion cultures, have thus far not been considered. This case study uses the Failure Modes and Effects Analysis (FMEA) method to evaluate the risks associated with implementing upstream single-use technology. The simulated model process was used to compare the risk level of single-use technology for a traditional fed-batch cell culture with that for perfusion culture, under the same annual protein production conditions. To provide a reasonable source of potential risk for FMEA, all single-use upstream operations for both fed-batch and perfusion processes were investigated using an analytical method developed to quantify the impact of process parameters and operating conditions on single-use system specifications and to ensure objectivity. Many of the risks and their levels, were similar in long-duration perfusion cultures and fed-batch cultures. However, differences were observed for high-risk components such as daily sampling and installation. The result of this analysis indicates that the reasons for risk are different for fed-batch cultures and perfusion cultures such as larger bioreactors in fed-batch and longer runs in perfusion, respectively. This risk assessment method could identify additional control measures and be part of a holistic contamination control strategy and help visualize their effectiveness.

Large-Scale Assessment of Extractables and Leachables in Single-Use Bags for Biomanufacturing

Single-use technologies (SUTs) are widely used during biopharmaceutical manufacture as disposable bioreactors or media and buffer storage bags. Despite their advantages, the risk of release of extractable and leachable (E&Ls) substances is considered an important drawback in adopting disposables in the biomanufacturing process. E&Ls may detrimentally affect cell viability or productivity or may persist during purification and present a risk to the patient if remaining in the final drug product. In this study, 34 plastic films from single-use bags (SUBs) for cell cultivation were extracted with selected solvents that represent reasonable worst-case conditions for most typical biomanufacturing applications. SUBs were incubated at small-scale under accelerated-aging conditions that represented standard operational conditions of use. Leachables analysis was performed following dispersive liquid-liquid microextraction (DLLME) for analyte preconcentration and removal of matrix interference. Resulting extracts were characterized by GC-headspace for volatiles, high resolution GC-Orbitrap-MS/MS for semivolatiles, high resolution LC-Orbitrap-MS/MS for nonvolatiles, and ICP-MS for trace elemental analysis. Multivariate statistical analysis of the analytical data revealed significant correlations between the type and concentration of compounds and bags features including brand, manufacturing date and polymer type. The analytical data demonstrates that, over recent years, the nature of E&Ls has been altered due to the implementation of manufacturing changes and new types of polymers and may change further with the future advent of regulations that will limit or ban the use of certain raw materials and additives. The broad E&L database generated herein facilitates toxicological assessments from a biomanufacturing standpoint and provides practical guidelines for confident determination of E&Ls to enable screening and elimination of nonsatisfactory films for single use bioprocessing.

Evaluation of solvent systems for optimized extractables studies of single use bioprocessing solutions

Despite their advantages, there is concern that single-use systems used in biopharmaceutical manufacture might release potentially toxic substances during standard unit operations that negatively impact cell growth. Characterization of the extractables profile for single-use systems is necessary to know which compounds potentially become leachables under operational cell culture conditions. A key issue in the design of extractables studies is the composition of the model solvent, in particular its pH and polarity. In this study, a new approach, based on design of experiments (DoE), has been applied to determine the composition of the model solvent for extractable profiling of single-use bags (SUBs). Particular focus was placed on the determination of the degradation products of the antioxidant Irgafos 168^®, due to evidence that some of these degradation products have cytotoxic effects on CHO cells. Results indicated that 2-propanol:water is the most appropriate solvent for the extraction of highly hydrophobic compounds with polar groups and/or acid-base properties from SUBs. The described DoE approach simplifies the number of experiments, evaluates all possible solvent water mixtures to select the best extraction solvent based on polarity, establishes the influence of each variable and provides information about variable interaction, which represents an important improvement over current best practice. The developed approach was applied to seven SUBs from different vendors and production dates facilitating the identification of potentially non-satisfactory films for cultivation of CHO cell lines under process conditions.