ASTM E3259-22
(Practice)Standard Practice for Process to Remove Retroviruses by Small Virus Retentive Filters
Standard Practice for Process to Remove Retroviruses by Small Virus Retentive Filters
SIGNIFICANCE AND USE
3.1 Mammalian cell lines are widely used in the production of biological therapeutics, such as monoclonal antibodies and other recombinant proteins. Some of these cell lines, like rodent cell lines, are known to contain genes encoding endogenous retroviral-like particles or produce endogenous retrovirus, but there is no evidence of an association between rodent retrovirus and disease in humans. Adventitious viruses can be introduced into a drug substance manufacturing process from other sources, and contamination of human therapeutics is a safety concern (3).
3.2 Virus filtration, an orthogonal technology in a virus clearance platform to such steps as low pH or surfactant inactivation, has traditionally been accepted as a robust method for virus clearance when well designed. Size exclusion has been shown to be the primary mechanism of virus removal by virus retentive filtration, that is, larger viruses are more easily retained than smaller viruses such as parvoviruses (4, 5). Large virus retention has also been shown to be insensitive to process fluid characteristics such as protein type, protein concentration, pH, and ionic strength (4, 6, 7, 8, 9, 10). In contrast, for small viruses, aspects like flow pausing and/or flux decay can impact clearance (4, 6, 11).
3.3 Large virus retentive filters, or retrovirus filters, are tested for removal of larger enveloped viruses like retrovirus or MuLV (80 nm to 100 nm) and have undetectable levels of the large bacteriophage PR772 (64 nm to 82 nm) (1). Small virus retentive filters, or parvovirus filters, are designed to remove parvovirus, like MMV (18 nm to 26 nm) (1). Since size exclusion has been demonstrated as the mechanism of virus retention, retroviruses, which are three to four times larger than parvoviruses, should be large enough to be completely retained, with undetectable levels of retrovirus in the filtrate, by all small virus retentive filters designed to remove parvovirus.
3.4 Numerous published studies...
SCOPE
1.1 This practice assures 6.0 log10 removal of retrovirus (for example, MuLV).
1.2 This practice is applicable to monoclonal antibody (mAb), immunoglobulin G (IgG) fusion proteins, recombinant proteins, or other proteins produced using mammalian cell lines (for example, Chinese hamster ovary (CHO), murine hybridomas, murine myelomas, or human embryonic kidney (HEK) 293).
1.3 The step is performed on cell-free intermediates.
1.4 The log removal claim for retrovirus by small virus retentive filters can be used in conjunction with other clearance unit operations (for example, low pH inactivation, or inactivation of virus by surfactant) to assure sufficient total process clearance of potential virus contaminants, which would be supportive of early phase (clinical phase 1 or phase 2a trials) regulatory filings.
1.5 Retrovirus removal claim by filtration is limited to small virus retentive filters, as defined in the PDA Technical Report Virus Filtration (1)2 in the context of this standard.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3259 − 22
Standard Practice for
Process to Remove Retroviruses by Small Virus Retentive
1
Filters
This standard is issued under the fixed designation E3259; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This practice assures 6.0 log removal of retrovirus (for
10
example, MuLV).
2. Terminology
1.2 This practice is applicable to monoclonal antibody
2.1 Definitions of Terms Specific to This Standard:
(mAb), immunoglobulin G (IgG) fusion proteins, recombinant
2.1.1 bacteriophage PP7, n—RNA bacteriophage that in-
proteins, or other proteins produced using mammalian cell
fects Pseudomonas aeruginosa bacteria that has a size of
lines (for example, Chinese hamster ovary (CHO), murine
approximately 30 nm to 33 nm, often used as a surrogate for
hybridomas, murine myelomas, or human embryonic kidney
parvovirus in virus retentive filter studies, but not for regula-
(HEK) 293).
tory clearance claims.
1.3 The step is performed on cell-free intermediates.
2.1.2 bacteriophage PR772, n—double-stranded DNA bac-
1.4 The log removal claim for retrovirus by small virus
teriophage that infects Escerichia coli bacteria that has a size of
retentive filters can be used in conjunction with other clearance
approximately 80 nm, often used as a surrogate for retrovirus
unit operations (for example, low pH inactivation, or inactiva-
in virus retentive filter studies, but not for regulatory clearance
tion of virus by surfactant) to assure sufficient total process
claims.
clearance of potential virus contaminants, which would be
supportive of early phase (clinical phase 1 or phase 2a trials) 2.1.3 log reduction value (LRV) or log reduction factor
10
regulatory filings.
(LRF), n—used to describe the degree of reduction of a
population; for virus filtration, LRV/LRF is calculated by
1.5 Retrovirus removal claim by filtration is limited to small
comparing the virus quantity before and after filtration.
virus retentive filters, as defined in the PDA Technical Report
–1
2
2.1.3.1 Discussion—Each log reduction (10 ) represents a
Virus Filtration (1) in the context of this standard.
90 % reduction in the population. For example, a process
1.6 The values stated in SI units are to be regarded as
–6
shown to achieve a 6-log reduction (10 ) will reduce a
standard. No other units of measurement are included in this
6
population from a million (10 ) to 1. The calculation for log
standard.
reduction is [log of total virus quantity in feed material or
10
1.7 This standard does not purport to address all of the
load] minus [log total virus quantity in filtrate or filtered
10
safety concerns, if any, associated with its use. It is the
product].
responsibility of the user of this standard to establish appro-
2.1.4 modular virus clearance validation, n—a modular
priate safety, health, and environmental practices and deter-
viral clearance study is one that demonstrates virus removal
mine the applicability of regulatory limitations prior to use.
and/or inactivation at individual steps during the purification
1.8 This international standard was developed in accor-
process (column chromatography, filtration, heat treatment,
dance with internationally recognized principles on standard-
solvent/detergent treatment, low pH treatment, and so forth).
ization established in the Decision on Principles for the
2.1.4.1 Discussion—Each module, or unit operation, in the
Development of International Standards, Guides and Recom-
purification scheme may be studied independently of the other
modules. Different model proteins may be used to demonstrate
viral clearance in different modules, if necessary. If the
1
This practice is under the jurisdiction of ASTM Committee E55 on Manufac-
purification process of a specific product (protein) differs at any
ture of Pharmaceutical and Biopharmaceutical Products and is the direct responsi-
bility of Subcommittee E55.12 on Process Applications.
Current edition approved Nov. 1, 2022. Published November 2022. DOI:
10.1520/E3259-22.
2
The boldface numbers in parentheses refer to a list of references at the end of
this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E3259 − 22
of the virus removal or inactivation modules from the model
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