Demonstrating Comparability for Biotechnology Products: Issues
and Challenges in a Global Environment.
Fredric G. Bader Global Biologics Supply Chain
Johnson & JohnsonACPA Meeting, 1 Oct 05
Contents• The Concept of Comparability
• Building the Comparability Data Base
• Comparability: Issues and Challenges
What is Comparable? (ICH Q5E)
• Comparable: A conclusion that products have highly similar quality attributes before and after manufacturing process changes and that no adverse impact on the safety or efficacy, including immunogenicity, of the drug product occurred.
•This conclusion can be based on an analysis of product quality attributes.
•In some cases, non-clinical or clinical data might contribute to the conclusion.
Comparability Requires Building the Product Database
It begins with discovery research and builds over the life of the productSome is in the public domain but most of it is in confidential company recordsThe size of the database becomes substantial
Analytical Data Available for Comparability
• For biotechnology products, there are approximately 3,000 to 5,000 assays/batch
•Raw Material Release: chemical, containers, resins, etc.•Utilities: air, O2, CO2, N2, steam(s), water(s)•Environmental: particulates, bioburden, air velocities,
pressure differentials, cleaning (rooms and equipment)•In-process controls: inoculum, fermentation, purification,
media, buffers•Product release: intermediates, drug substance, drug product•Stability: intermediates, buffers, drug substance, drug product
•Trending of data establishes a comparability database:•Environmental, utilities, raw materials, process, product, clinical
We Learn from Unplanned ChangesWash step for chromatography column #2Wash buffer pH: Filed 6.0 to 7.0
Batch record limits 6.3 to 6.7Wash step occurs at pH 6.2 (Invokes a noncomformance)Investigation occurs:
Determine cause faulty pH probeCorrective action replace probe
Impact on product- Review development data on pH effects- Review all downstream process data against trends- Review product data against trends- Review against historical nonconformances- Determine need for additional characterization assays- Consider additional development studies if needed- Consider putting batch on stability (normal & accelerated)
Discuss with regulatory on need to notify agencies or not
Note:The more you understand the
molecule, the easier it is to apply comparability
•Characterization assays: “The measurement of quality attributes in characterization studies does not necessarily entail the use of validated assays but the assays should be scientifically sound and provide results that are reliable.”(ICH Q5E)•Clinical data: PK, PD, PK/PD, clinical efficacy, safety, immunogenicity, pharmacovigilance studies
Recombinant Human Erythropoietin
Absent the carbohydrate, the molecule is too small to be retained by the kidneys.Absent the sialic acids, the molecule is removed by the liver.
Mr approx. 30,600
165 amino acids
Approx. 38% carbohydrate
Carbohydrate chains are in Cyan. Hydrophobic amino acid residues are in Red, hydrophilic residues are in Blue.
Typical Analytical/Characterization Methods
ProteinA280A280/A260SDS Page (CB)SDS Page (silver)Western blotPeptide Mapping
trypticLys-C
rp HPLCN-terminal sequenceC-terminal sequenceIsoelectric focusingAmino acid compositionCircular dichroismMethionine oxidationDeamidationFluorescence SpecMass Spec
AggregatesSEC HPLCWestern blotAnalytical UltracentrifugeLight scatteringVisible particlesSub visible particles
CarbohydrateSialic acidNeutral sugar contentN-linked oligosaccharidesMonosaccharidesIsoelectric focusingCapillary electrophoresis% NGNA
ActivityIn vivo bioassayCellular bioassayRadioimmuno assayELISA
GeneralpHAppearanceExcipientsBioburden/sterility
PuritySDS pageEndotoxinsbioburdenHost DNAHost cell proteinLeachates
Focus on Carbohydrates
There are multiple ways to look at the carbohydrate structures in a molecule. One needs to have sufficient methods to verify that the carbohydrate is intact.
Monosaccharides by HPLC
Provides a measure of the relative amounts of the Monosaccharidesthat make up the carbohydrate structure
N-Linked Oligosaccharide Map –Typical Chromatogram
Demonstrates the relative amounts of di-, tri- and tetra sialylatedstructures of the intact n-linked carbohydrates
Total Sialic Acid and NGNA –Typical Chromatograms
Internal Standard
Internal Standard
Measures total Sialic Acid and NGNA. Presence of Sialic Acid is critical to the half-life of EPO in the patient.
Capillary Electrophoresis -Representative Electropherograms
min0 20 40 60 80
mAU
-4
-2
0
2
4
6
8
10
12
DAD1 B, Sig=214,10 Ref=off (D:\EPO\2003\MARCH\17MAR002.D)
1 23
4
5 6
7
8
Ph. Ph. EurEur. BRP Standard. BRP Standard
min0 20 40 60 80
mAU
-4
-2
0
2
4
6
8
10
12
DAD1 B, Sig=214,10 Ref=off (D:\EPO\2003\MARCH\17MAR005.D)
EpoetinumEpoetinum alfaalfa Purified BulkPurified Bulk
Capillary electrophoresis measures the proportion of EPO molecules that contain 7 (left) to 14 (right) sialic acids
Capillary Electrophoresis –Drug Substance and Product
Capillary electrophoresis measures the different charge isoforms of EPO, due to number of sialic acids on the molecule
It can be used to demonstrate:Consistent proportions of the 6 - 8 isoforms over time in both drug substance and productDrug product is stable during the formulation process, no difference between bulk and the corresponding lot of productDrug product is stable over shelf-life, no difference between release and at expiry
Comparability is a Positive Concept
The development of the concept of comparability by the FDA in the early 1990’s provided a great benefit to industry
Molecules before and after a change had to be comparable, but not identical (an analytical impossibility)
The concept that all changes do not create the same level of risk was formalized and categories were created
Prior Approval30 Day Change Being EffectedChange Being Effected - Annual report
Comparability protocols were allowed to pre-establish the requirements and in some cases, lower the change level
The requirements to support a change became dependent upon the type of change, the knowledge of the molecule and the clinical indications
Higher riskModerate riskLittle or no risk
What is Comparable? (ICH Q5E)
• Comparable: A conclusion that products have highly similar quality attributes before and after manufacturing process changes and that no adverse impact on the safety or efficacy, including immunogenicity, of the drug product occurred.
•This conclusion can be based on an analysis of product quality attributes.
•In some cases, non clinical or clinical data might contribute to the conclusion.
Comparability: Preparing to make a change
• Making a change requires the following process:•Determine the reason and type of change that you want or need to make•Assemble the following experts
•Manufacturing•Regulatory•Quality•Process Sciences•(Clinical)
•Determine the potential effects that the change could have on the product•Determine alternative ways to address the need for a change
•Develop a change strategy that minimizes the risk to product & quality and provides the fastest route for approval
Comparability: Issues and Challenges:
1. Multiple agencies with different perspectives and timelines
Europe US JapanSwitzerland Canada AustraliaPlus > 100 smaller agencies that leverage off of majors
• Similar in basic philosophy (ICH Guidelines)• Different in details
• What constitutes a change• What is required for a change approval• Requirements for specifications• Regulatory pathway and timing• Questions received back on submissions
Comparability: Issues and Challenges
2. Massive amounts of data and changes to track• Large noisy databases, need Critical Process Parameters• 3,000 to 5,000 assays per batch• 100’s to 1,000’s of pages of batch records per batch• Enormous amounts of process control data• IQ, OQ, PQ reports, deviations, technical reports• Multiple changes per product per year
• Required by regulatory agencies• Required by vendor/supplier changes• To improve quality/consistency considerations• To meet market demands (yield/scale-up)
• Time differences between agencies leads to multiple versions of a process
Comparability: Issues and Challenges
3. Limitations of Analytical Methods• Lets look at aggregates• Monomers SEC-HPLC• Dimers SEC-HPLC• Oligomers SEC-HPLC?, SDS-PAGE gels?• Sub-micron AUC?, Light Scattering?• Sub visible/visible particle counters
For SEC-HPLC, larger particles may not be able to enter the column or may disassociate on the column
Gels are hard to quantifyAUC/Light Scattering can be complex and may not work in final
formulationsThere appears to be no relationship between dimers/oligomers and
sub-visible/visible proteinaceous particles
Comparability: Issues and Challenges
4. Lack of correlation of product attribute to clinical outcomes• Little information exists on the correlation of aggregate
type and concentration with adverse effects• The affect of modification of one amino acid
(oxidation/deamidation) on a molecule can be very site and species specific
• Carbohydrate is extremely important in some molecules and has no effect on others
• Many products are actually collections of multiple forms of the same protein sequence due to post-translational modifications
• It is very difficult to correlate product attributes to clinical outcomes
What can happen if you do not conduct changes correctly
The FDA issued a Warning Letter on 22 July, 2005 to XXXX(YYYY Plant) for failure to alleviate GMP issues associated with production of asparaginase (the active ingredient in XXXX’s acute lymphocytic leukemia treatment ZZZZ). This was following a FDA Form 483 being issued to XXXX for a 15 –18 February, 2005 inspection of the same facility for “significant deviations in the manufacturing of asparaginase intermediate”.
In the 483, the agency stated that XXXX did not submit the necessary supplements for changes in its manufacturing process that were significant departures from the current biologics license. XXXX “failed to notify FDA upon establishing a new working cell culture from a pre-existing working cell culture”. This form of passaging was not allowed for in the current license and ultimately resulted in a product that the FDA deemed to be different from the existing one. Also, XXXX did not submit a prior approval supplement (PAS) for a re-isolation procedure and failed to characterize the isolate prior to use in production of asparaginase. Ultimately, XXXX’s response received by the FDA on March 15, 2005 was deemed inadequate and a Warning Letter was issued.
Due to the fact that XXXX did not fully characterize the new working cell bank and re-isolated cell lines to determine whether their attributes were consistent with the cell lines in the master cell bank, the FDA deemed that there was no assurance that the product meets the quality and purity characteristics it purports to do and are in violation of the FD&C Act. As stated by the FDA, XXXX failed to reference any evaluation or characterization of the working cell culture as part of the evaluation performed nor did they compare it to the master cell culture. They also stated that there were no corrective actions for the culture management facility in AAAA for improper preparation of the working cell bank.
Additionally, XXXX did not use a robust comparability program for assessing the intermediate column feed for the reisolate versus the intermediates from the working cell bank. XXXX was also cited for not using the most appropriate guidance documents; in this case XXXX referenced a reliance upon the CBER Guidance (Content and Format of CMC Information and Establishment Description Information for a Vaccine or Related Product, January 1999), whereas FDA stated that the company should have used ICH Q6B (Specifications: Test Procedures and Acceptance Criteria for Biotechnological / Biological Products, August 1999) instead. FDA also recommended that XXXX expand and modernize their specification / characterization procedures and practices.
FDA instructed XXXX that a written response to the Warning Letter is required within 15 business days or receipt of the Warning Letter. The response should include any steps that have been taken or will be taken to correct the noted violations and prevent recurrence. If actions cannot be completed within 15 business days, the reason for the delay and the expected completion times should be included. The FDA stated that failure to promptly correct the deviations noted could result in further regulatory action (license suspension, license revocation, seizure and/or injunction) without further notice.
Main Points of Warning Letter“failed to notify FDA upon establishing a new working cell culture
from a pre-existing working cell culture”did not submit a prior approval supplement (PAS) for a re-isolation
procedure and failed to characterize the isolate there was no assurance that the product meets the quality and purity
characteristics it purports to do and are in violation of the FD&C Act
did not use a robust comparability program for assessing the intermediate column feed
was also cited for not using the most appropriate guidance documents
failure to promptly correct the deviations noted could result in further regulatory action (license suspension, license revocation, seizure and/or injunction) without further notice
Comparability Versus Biosimilarity
• Comparable: Requires comparison by a manufacturer against the same product previously produced in manufacturing operations under its control
•Biosimilar: Requires comparison by a new manufacturer against an existing approved commercial product produced by a separate manufacturer
•During the development of a Biosimilar Product, the Biosimilar manufacturer will be required to demonstrate Comparability against its own previous batches as it modifies and scales up the process and transfers the process from one facility or scale to another
Approval Requirements for Changes Required for Comparability and Biosimilarity
Very LikelyUnlikely -Depends on type of change
Clinical Immunogenicity Study
Very LikelyUnlikely -Depends on type of change
Clinical Efficacy Study
Very LikelyUnlikely -Depends on type of change
Clinical Safety Study
Very LikelyUnlikely -Depends on type of change
Equivalent PD
YesUnlikely -Depends on type of change
Equivalent PK
YesYesEquivalent Bioactivity
YesYesEquivalent Route of Delivery
YesYesEquivalent Dosage Form
YesYesEquivalent Product Characterization
YesYesEquivalent Release Specifications
Required for Biosimilar
Required for Comparable
Requirement to Demonstrate
Approval Requirements for Types of Changes Required for Comparability
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
New cell line (Prior Approval)
NoNoClinical Immunogenicity Study
NoNoClinical Efficacy Study
NoNoClinical Safety Study
NoNoEquivalent PD
NoNoEquivalent PK
YesNoEquivalent Bioactivity
YesYesEquivalent Product Characterization
YesYesEquivalent Release Specifications
Scale-up (CBE 30?)
Raw Material (Annual Report?)
Requirement to Demonstrate
Decisions on what is required requires input from your regulatory group and possibly the Health Authorities
Conclusions• Comparability is an extremely useful tool for analyzing the effect of changes in biotechnology products
• Comparability has provided a rational basis for making decisions related to process changes
• Under ICH Q5E, the philosophy for using comparability has been established worldwide
• Local differences in the detailed application of comparability will likely exist based upon the experiences and resources of the various agencies
• Even with application of comparability, undetected changes in a product can occur
