Title: Validation of Virus Removal
1Validation of Virus Removal
Deputy Director, Div. of Monoclonal
Antibodies OTRR/CBER/FDA PDA/FDA
Meeting September 26, 2000
2SCOPE - Products
- Specified Biologics
- Monoclonal Antibodies
- rDNA-derived products
- Traditional Biologics
- Some Blood-products
- Some Vaccines
3SCOPE - Methods
- Column Chromatography
- Nano-Filtration (Viral Filtration)
- Other Methods
- Precipitation
- Centrifugation
4Example
Production Fermentor
Protein A affinity chromatography
Anion Exchange Chromatography
Virus filtration
Gel Filtration
Formulation and Fill
5GENERALITIES
- Validation conditions must be representative of
the actual manufacturing process. - Validation should use virus-spiking studies.
- Viral clearance studies should not be done in the
production facility. - Validations should be done in duplicate.
6SCALE-DOWN
- Scale Down
- Allows validation to be performed in testing labs
- Maintains high titers of the spiking virus
- Must be done appropriately
7CHROMATOGRAPHY
- Parameters that should be representative of
commercial-scale manufacturing - CHROMATOGRAPHY MEDIUM
- COLUMN BED HEIGHT
- LINEAR FLOW RATE
- BUFFER COMPONENTS AND CONCENTRATIONS
- pH
- TEMPERATURE
- PRODUCT LOAD
8CHROMATOGRAPHY
- and
- the chromatographic profile and product
recovery of the scale-down process should be
comparable to that of the manufacturing process.
9FILTRATION
- Parameters that should be representative of
commercial-scale manufacturing - VISCOSITY
- VOLUME PER cm2 OF FILTER AREA
- IONIC STRENGTH
- TEMPERATURE
- pH
- PROTEIN COMPOSITION CONCENTRATION
10FILTRATION
- and
- the product recovery of the scale-down process
should be comparable to that of the manufacturing
process.
11CHOOSING VIRUSES
- The aims of viral validation studies are
- to provide evidence that the production process
will effectively remove viruses which are either
known to contaminate the starting materials, or
which could conceivably do so, and - to provide indirect evidence that the production
process might remove novel or unpredictable virus
contamination.
12CHOOSING VIRUSES
- The clearance validation should include
- relevant viruses that may be anticipated to occur
in the system - specific model viruses that are physically and
chemically similar to relevant viruses - non-specific model viruses that represent the
extremes of virus properties
13CHOOSING VIRUSES
- Examples of model viruses
- Retrovirus X-MuLV
- Small non-enveloped virus SV40, parvovirus,
polio virus 1 - Medium to large enveloped RNA virus
Parainfluenza, Sindbis virus - Medium to large DNA virus HSV-1, pseudorabies
virus
14PRECAUTIONS
- Avoid aggregation of spiking virus
- Use small volumes of spiking virus in order to
retain the sample composition. - Assess the potential for assay interference by
the product or buffers. - Use control assays in parallel to assess the loss
of infectivity due to dilution, concentration,
filtration, or storage. - Include controls to demonstrate the effect of
procedures used solely to prepare the sample for
assay.
15General Procedure
- Titer Sample Load
- Take Hold Control sample
Add high Titer Spike to Sample Load
- Titer Hold Control
- Titer Column Flowthrough
- Titer Eluate Sample
16Virus Assay Methodology
- Infectivity is the standard method for clearance
studies. - PCR assays and Polymerase Enhanced Reverse
Transcriptase assays are being developed.
17Evaluation of Results
- Clearance factors from sequential orthogonal
processes may be combined to give a Cumulative
Clearance Factor - Orthogonal processes are those that clear virus
by independent modes of action (e.g., Anion
Exchange chromatography and Cation-Exchange
chromatography)
18Evaluation of Results
- Beware of including both
- a low-pH treatment step and
- a chromatography step that uses elution at a low
pH - in the Cumulative Clearance Factor.
19Evaluation of Results
- The Cumulative Clearance Factor must be
substantially greater than the estimated number
of virus particles in a volume of the starting
material required to produce a human dose of the
drug.
20Evaluation of Results
- The number of virions per mL of starting material
should generally be estimated by Transmission
Electron Microscopy. - One dose of product is generally considered to
be the total regimen of drug. - e.g., 1 mg/week x 4 weeks 4 mg dose
21Example
Product
Homologous Product
Protein A affinity chromatography
Anion Exchange Chromatography
Virus filtration
Gel Filtration
Formulation and Fill
22Generic and Modular Validation
- A generic validation study demonstrates virus
removal or inactivation by a process using a
model product and allows the use of that process
with an homologous product without the need to
revalidate.
23Generic and Modular Validation
- Generic viral clearance validation is applicable
to situations when the purification process of a
product is the same as a process that has already
been validated for an homologous product.
24Chromatography
- The two processes must have the same
- -chromatography medium,
- -column geometry,
- -equilibration buffers,
- -load composition concentration,
- -elution buffers,
- -elution parameters,
- -wash procedure.
25Virus Filtration
- The two processes must have the same
- type of virus filter
- solution characteristics
- VOLUME PER cm2 OF FILTER AREA
- IONIC STRENGTH
- TEMPERATURE
- pH
- PROTEIN COMPOSITION CONCENTRATION
26Generic and Modular Validation
- Example of Homologous Products
- Monoclonal Antibodies of the same species, class,
and subclass and derived from the same source
(e.g., ascites, tissue culture, etc.) and cell
substrate.
27Generic and Modular Validation
- NOTE
- GENERIC VALIDATIONS ARE NOT APPLICABLE TO
HUMAN-DERIVED PRODUCTS OR PRODUCTS THAT MAY BE
CONTAMINATED WITH HUMAN PATHOGENS.
28Post-Approval Changes
- Whenever a change is made in the production or
purification process, the effect of that change
on the viral clearance should be considered and
the system re-validated as needed.
29Additional Reading
- ICH Guidance on Viral Safety Evaluation of
Biotechnology Products Derived from Cell Lines of
Human or Animal Origin,1998 (www.fda.gov/cber/guid
ance/) - Points to Consider in the Manufacture and Testing
of Monoclonal Antibody Products for Human Use,
1997 (www.fda.gov/cber/guidance/) - Guideline on General Principles of Process
Validation, 1987 (www.fda.gov/cder/guidance/pv.htm
) - Reviewer Guidance Validation of Chromatographic
Methods, 1994 (www.fda.gov/cder/guidance/) - Validation of the Purification Process for Viral
Clearance Evaluation, 1997, A.J. Darling, in
Biopharmaceutical Process Validation, G. Sofer
and D.W. Zabriskie, editors. Marcel Dekker, Inc
(New York)
30Guidance
- CBER Office of Therapeutics 301-827-5101
- CBER Office of Vaccines 301-827-3070
- CBER Office of Blood 301-827-3524
31Obtaining Documents
- Fax (888) CBER-FAX
- Internet http//www.fda.gov/cber/guidelines.htm
- E-mail OCTMA_at_CBER.FDA.GOV
- Mail Training and Manufacturer Assistance
- (HFM-40) CBER/FDA
- 1401 Rockville Pike
- Rockville, MD 20852-1448