A Survey of Quality Attributes of Virus Spike Preparations Used in Clearance Studies

Anion exchange (AEX) is a common downstream purification operation for biotechnology products manufactured in cell culture such as therapeutic monoclonal antibodies (mAbs) and Fc-fusion proteins. We present a head-to-head comparison of the viral clearance efficiency of AEX adsorbers and column chromatography using the same process fluids and comparable run conditions. We also present overall trends from the CDER viral clearance database. In our comparison of multiple brands of resins and adsorbers, clearance of three model viruses (PPV, X-MuLV, and PR772) was largely comparable, with some exceptions which may reflect run conditions that had not been optimized on a resin/membrane specific basis.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Viral clearance by flow‐through mode ion exchange columns and membrane adsorbers

Miesegaes

Lute

Read

et al. 2013

“…Interestingly, previous study demonstrated considerable variability in P/I ratio (almost 2.0 Log 10 between the highest and the lowest) among commercial virus stocks. 12 Besides the scientific aspects, these findings also can contribute to optimize manufacturing costs for a VF process of given product.…”

Section: Effects Of Particle-to-infectivity Ratio On Virus Filtrationmentioning

confidence: 99%

“…Although this variability in virus characteristics and evaluation are recognized as potential problems within the biopharmaceutical industry, their impacts on VCS are considered to be modest and no quantitative studies have been reported to date. 8,12 However, the impact of such topics on virus removal performance should also be discussed since inconsistency in the apparent virus amount can promote virus overloading. As the physiochemical properties of these virus particles are nearly identical, 13 a virus removal method involving physical capture should equally retain all particle types.…”

Section: Introductionmentioning

confidence: 99%

Particle‐based analysis elucidates the real retention capacities of virus filters and enables optimal virus clearance study design with evaluation systems of diverse virological characteristics

Kayukawa

Yanagibashi

Hongo‐Hirasaki

et al. 2022

In virus clearance study (VCS) design, the amount of virus loaded onto the virus filters (VF) must be carefully controlled. A large amount of virus is required to demonstrate sufficient virus removal capability; however, too high a viral load causes virus breakthrough and reduces log reduction values. We have seen marked variation in the virus removal performance for VFs even with identical VCS design. Understanding how identical virus infectivity, materials and operating conditions can yield such different results is key to optimizing VCS design. The present study developed a particle number‐based method for VCS and investigated the effects on VF performance of discrepancies between apparent virus amount and total particle number of minute virus of mice. Co‐spiking of empty and genome‐containing particles resulted in a decrease in the virus removal performance proportional to the co‐spike ratio. This suggests that empty particles are captured in the same way as genome‐containing particles, competing for retention capacity. In addition, between virus titration methods with about 2.0 Log10 difference in particle‐to‐infectivity ratios, there was a 20‐fold decrease in virus retention capacity limiting the throughput that maintains the required LRV (e.g., 4.0), calculated using infectivity titers. These findings suggest that ignoring virus particle number in VCS design can cause virus overloading and accelerate filter breakthrough. This article asserts the importance of focusing on virus particle number and discusses optimization of VCS design that is unaffected by virological characteristics of evaluation systems and adequately reflect the VF retention capacity.

“…pressure, filter loading), virus/protein interactions, process stream properties (product concentration, buffer matrix, process residuals, aggregates), amount of virus spike (PFU), and quality of virus spike per PDA tech report 47 6 and Miesagaes et al 7 . Similar to process stream purity, virus spike impurities are composed of two parts: product-related (fragments, viral subunits or subparticles, and potential aggregates) and process-related (host cell proteins, DNA, and metabolites).…”

Section: Introductionmentioning

confidence: 99%

Limits in virus filtration capability? Impact of virus quality and spike level on virus removal with xenotropic murine leukemia virus

Roush

Myrold

Burnham

et al. 2014

Virus filtration (VF) is a key step in an overall viral clearance process since it has been demonstrated to effectively clear a wide range of mammalian viruses with a log reduction value (LRV) > 4. The potential to achieve higher LRV from virus retentive filters has historically been examined using bacteriophage surrogates, which commonly demonstrated a potential of > 9 LRV when using high titer spikes (e.g. 10(10) PFU/mL). However, as the filter loading increases, one typically experiences significant decreases in performance and LRV. The 9 LRV value is markedly higher than the current expected range of 4-5 LRV when utilizing mammalian retroviruses on virus removal filters (Miesegaes et al., Dev Biol (Basel) 2010;133:3-101). Recent values have been reported in the literature (Stuckey et al., Biotech Progr 2014;30:79-85) of LRV in excess of 6 for PPV and XMuLV although this result appears to be atypical. LRV for VF with therapeutic proteins could be limited by several factors including process limits (flux decay, load matrix), virus spike level and the analytical methods used for virus detection (i.e. the Limits of Quantitation), as well as the virus spike quality. Research was conducted using the Xenotropic-Murine Leukemia Virus (XMuLV) for its direct relevance to the most commonly cited document, the International Conference of Harmonization (ICH) Q5A (International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, Geneva, Switzerland, 1999) for viral safety evaluations. A unique aspect of this work is the independent evaluation of the impact of retrovirus quality and virus spike level on VF performance and LRV. The VF studies used XMuLV preparations purified by either ultracentrifugation (Ultra 1) or by chromatographic processes that yielded a more highly purified virus stock (Ultra 2). Two monoclonal antibodies (Mabs) with markedly different filtration characteristics and with similar levels of aggregate (<1.5%) were evaluated with the Ultra 1 and Ultra 2 virus preparations utilizing the Planova 20 N, a small virus removal filter. Impurities in the virus preparation ultimately limited filter loading as measured by determining the volumetric loading condition where 75% flux decay is observed versus initial conditions (V75). This observation occurred with both Mabs with the difference in virus purity more pronounced when very high spike levels were used (>5 vol/vol %). Significant differences were seen for the process performance over a number of lots of the less-pure Ultra 1 virus preparations. Experiments utilizing a developmental lot of the chromatographic purified XMuLV (Ultra 2 Development lot) that had elevated levels of host cell residuals (vs. the final Ultra 2 preparations) suggest that these contaminant residuals can impact virus filter fouling, even if the virus prep is essentially monodisperse. Process studies utilizing an Ultra 2 virus with substantially less host cell residuals and highly monodispersed virus particles demonstrated superior per...