Establishing a Testing Strategy
for a QbD Development Product
Mary Cromwell
Director, Protein Analytical Chemistry
Genentech
CMC Strategy Forum
July 20, 2010
Bethesda, MD
A-MAb Case Study: Elements of the Control Strategy
Raw Material Control
Procedural Controls
Process Parameter Controls
Process Control
In-Process Testing
Specifications
(Lot Release and Stability)
Characterization
and Comparability Testing
Process Monitoring
Continual Process Verification
Testing
Today’s Discussion
Key Tools and Information Used to Develop a
Testing Strategy for a QbD Product
QA Impact
Score
QA Uncertainty
Score
Time, Information
CQA Identification
CQA Acceptance
Criteria
Process Impact
Score
Stability Impact
Score
Testing Strategy
Testing Strategy
Robustness
Assessment
Table
QA Specific
Decision Tree
RRF
Quality Attribute Impact Score
3
Impact &
Rating
Biologica
1
l Activity
PK
Immunogenicity
Safety
(Potential or Observed)
Very High
(20)
>100%
change
>40% change
on PK
ATA (Anti-Therapeutic
Antibodies) detected that may
life threatening
Irreversible or lifethreatening AEs and/or life
threatening loss of efficacy
High
(16)
40-100%
change
20-40%
change with
ATA detected that may be
associated with non-life
Reversible AEs and/or loss
of efficacy that is not life
impact on PD
threatening loss of efficacy
threatening
ATA detected with effect that can
be managed by clinical treatment
(i.e. dose titration, medication,
etc.)
AE that can be managed by
clinical treatment (i.e. dose
titration, medication, etc.)
ATA detected with effect on PK
or PD, but no effect on safety or
efficacy
Safety or efficacy effect
with minimal clinical
significance
2
Moderate
(12)
20-40%
change
20-40%
change with
no impact on
PD
Low
(4)
<20%
change
<20% change
with no
impact on PD
None (2)
No
change
No impact on
PK or PD
1
3
ATA not detected or ATA
detected with no effect on PK,
PD, safety, or efficacy
No effect on safety of
efficacy
Based on a relevant potency assay and dependent on assay variability
Based on serum exposure (AUC) or FcRn binding. PD considered if information available
3 Based on effects observed in clinical studies
2
P. Motchnik
CQA Acceptance Criteria (CQA-AC) and
Target Ranges (CQA-TR)
• CQA-AC:
– Numerical limits that must be met for the product to be
considered acceptable
– Based on non-clinical and clinical experience, platform
knowledge and literature (with appropriate justification of
applicability of data used)
– Based on patient impact only - process capability is not
considered
– May change as product gains more clinical experience, not as a
function of additional manufacturing experience
• CQA-TR:
– Constrained range of the CQA-AC to ensure that the process
will always deliver product within the CQA-AC
Attribute Testing Strategy Risk Ranking and
Filtering Tool
Quality
Attribute
Impact Score
X
Process or Stability
Impact Score
2, 4, 12, 16, 20
1, 2, 4, 10
Performed for:
• DS manufacturing process
• DP manufacturing process
• DS storage
• DP storage
(1) Attribute Testing Strategy
=
ATS (1)
2-200
Defines Testing Strategy:
• No Testing
• “Comparability and Monitoring”
• Control System (Release, Stability,
and/or In-Process)
Process Impact Scoring Decision Tree: Used for
DS and DP Manufacturing Processes
Start: For each
Quality Attribute
QA
Impact Score
of 2 or 4
Yes
Process Impact
Score = 4
No
Abundance
0-1%*
No
Yes
Process Impact
Score = 1
*specific for product-related
impurities; for HMWS,
Abundance threshold is
<0.1%
representative
process
model exists
No
Process Impact
Score = 10
PC/PV Outcome
Default
Process Impact
Score = 10
N. McKnight
Process Impact
Score = 4
Difference:
Actual Result to
CQA-TR
Highly Robust
Process Impact
Score = 2
Yes
Stability Impact Scoring Decision Tree
Start: for each
Quality Attribute
Can molecule
form attribute?
No
Process Impact
Score = 1
Yes
Process Impact
Score = 2
Slow
(< 11%*)
*of allowable range;
Assessed to expiry at recommended
storage temperature and for allowable
excursions
Rate of change
relative to CQA-AC
(>33%*)
Moderate
Process Impact
Score = 4
R. Wong
Fast
Process Impact
Score = 10
(11-33%*)
Attribute Testing Score: Defines Testing Strategy
Attribute Testing Strategy (ATS) Scoring Matrix
CQA Impact
Score
Process
or Stability
Impact Score
2
(Very Low)
4
(Low)
12
(Moderate)
16
(High)
20
(Very High)
a
12
16
20
a
4
4
a
8
a
24
32
40
4
8
16
48
64
80
10
20
120
160
200
1
2
2
a
a
40
ATS Score:
< 21
No testing required.
21-50
Comparability and Process Monitoring testing required.
> 50
Control system testing required.
“Comparability and Monitoring” (CaM)
• Attribute class to be tested as part of:
• Comparability exercises
– Performed to support site transfer, version changes, scale changes
– Provides streamlined testing
> Testing includes appropriate (DS or DP) tests designated “CaM” in the Testing
Strategy as well as Control System testing (IP, Lot Release, Stability)
> Choice of tests based on risk associated with change; only CaM attributes
known to be impacted by particular step that is changing will be tested
• Process Monitoring
– Continuous Process Verification
> Subset of CaM attributes
> Frequency of monitoring may be attribute dependent
> Control System testing
> Key Performance Indicators
Application of Attribute Testing Strategy
Tool
MAb 1: Background
• Target Product Profile
• Immunology indication
• Drug will be administered IV monthly for six months
• Doses up to 5X of proposed marketed dose given in clinical trials
• Very low immunogenicity rate
• Safety profile well established
• Product characterization
• Effector function required for potency
– CDC (terminal galactose distribution)
– ADCC (afucosylation)
• CDR deamidation, fragmentation, aggregation impact potency
– Deamidation increases ~ 6% on DP storage (allowable range = 9%)
– Fragmentation increases ~1% on DP storage (allowable range = 5.8%)
– Aggregation does not change on storage of DS or DP
ATS for Acidic Variants
Parameter
CQA Impact Score
CQA Acceptance Criteria
CQA Target Range for
DS Process
Process Impact Scores
Rationale
Based on potency impact in CDC and
ADCC assays
12
 45%
Based on level required to maintain
potency  80%.
 34%
Based on level required to ensure that DP
meets acceptance criterion at end of shelf
life
DS Process
10
Worst-case conditions across all
operations result in a batch that exceeds
the CQA-TR; Restriction Relationship and
Adaptive Design Space employed
DP Process
4
Changes during ambient handling and
excursions
DS Stability
2
No changes observed throughout
development
DP Stability
10
Significant changes observed over shelf life
and during excursions
Testing Strategy (CQA Impact score X Process Stability Impact score)
DS Process
120
Control system testing
Attribute Testing Strategy DP Process
Scores
DS Stability
48
“Comparability and Monitoring” testing
24
“Comparability and Monitoring” testing
DP Stability
120
Control system testing
ATS for CHOP (Application to Process-Related Impurities)
Parameter
CQA Impact Score
Rationale
20
Based on potential for Immunogenicity
CQA Acceptance Criteria
≤ 25 ppm
Based on dosing at 5x proposed to-bemarketed dose with no difference in
observed ATA incidence
CQA Target Range for
DS Process
≤ 23 ppm
Process Impact Scores
Truncated standard 5% CQA-AC reduction.
DS Process
2
Highly robust
DP Process
1
Will not involve cells
DS Stability
1
Will not change on stability
DP Stability
1
WIll not change on stability
Testing Strategy (CQA impact score X process/stability impact score)
DS Process
40
“Comparability and Monitoring” testing
Attribute Testing Strategy DP Process
Scores
DS Stability
20
No testing
DP Stability
20
20
ATA  anti-therapeutic antibodies; CDC  complement-dependent cytotoxicity; CQA  Critical
Quality Attribute; CQA-TR  Critical Quality Attribute Target Range; DS  Drug Substance;
DP  Drug Product; NA  not applicable.
ATS for Fragmentation (application of Abundance Filter)
Parameter
CQA Impact Score
CQA Acceptance Criteria
CQA Target Range for
DS Process
Process Impact Scores
Rationale
20
Based on potency impact in CDC and
ADCC assays; altered PK
 5.8% Fab
Ensures acceptable potency and PK
Abundance of  1% indicates that
establishing a target range is not required.
NA
DS Process
1
Abundance <1%
DP Process
1
Abundance < 1%
DS Stability
2
No changes observed throughout
development
DP Stability
4
Change of ~1% observed during
recommended storage/allowable
excursions
Testing Strategy (CQA impact score X process/stability impact score)
DS Process
20
No testing
Attribute Testing Strategy DP Process
Scores
DS Stability
20
40
“Comparability and Monitoring” testing
DP Stability
80
Control System testing required
ADCC  antibody-dependent cellular cytotoxicity; CDC  complement-dependent cytotoxicity;
CQA  Critical Quality Attribute; DS  Drug Substance; DP  Drug Product; NA  not applicable;
PK  pharmacokinetics; NA = Not applicable.
ATS for Afucosylation (Stability)
Parameter
CQA Impact Score
Rationale
20
Based on potency impact in ADCC assay
CQA Acceptance Criteria
1.6-12.1%
Based on clinical experience and levels to
maintain ADCC potency
CQA Target Range for
DS Process
1.7-11.5%
Standard 5% CQA-AC reduction applied to
both limits
Process Impact Scores
DS Process
10
Significant process variability observed
DP Process
1
Will not be impacted by DP Processing
DS Stability
1
Will not change on stability
DP Stability
1
Will not change on stability
Testing Strategy (CQA impact score X process/stability impact score)
DS Process
200
Attribute Testing Strategy DP Process
Scores
DS Stability
20
DP Stability
20
20
Control system testing
No testing
ADCC  antibody-dependent cellular cytotoxicity; CDC  complement-dependent cytotoxicity;
CQA  Critical Quality Attribute; DS  Drug Substance; DP  Drug Product; NA  not applicable.
Key Tools and Information Used to Develop a
Testing Strategy for a QbD Product
QA Impact
Score
QA Uncertainty
Score
Time, Information
CQA Identification
CQA Acceptance
Criteria
Process Impact
Score
Stability Impact
Score
Testing Strategy
Testing Strategy
Robustness
Assessment
Table
QA Specific
Decision Tree
RRF
Robustness Assessment of Testing Strategy
• Testing Strategy Tool used to develop the proposed Control System
• Is proposed testing strategy of sufficiently low risk?
• Do proposed methods provide adequate control?
• Robustness Assessment Tool considers
• ATS score (reflecting CQA Impact and Process/Stability control)
• Sensitivity of method used for analysis
• Testing Strategy (Control System, “CaM”, no testing)
• Expected to be iterative process: Unacceptable score indicates that
• Testing strategy may need to change
• A more sensitive method may be required for testing attribute
• Manufacturing process may need to provide greater process control
• Shelf-life/allowable excursions may need to be shortened
Robustness Assessment of Testing Strategy
Attribute
Testing Score
2-200
X
Testing
= Robustness
Strategy Score
Score
2, 4, 6, 10
4 - 2000
Score </= 400 indicates Robust Control Strategy
Testing Strategy Scoring for Robustness Assessment RRF
Score
Description
2
Attribute is measured directly with a suitably sensitive assay (IP or
LR/Stability).
4
The impact of an attribute is measured in a surrogate assay, is measured
collectively, or is measured directly with a relatively insensitive assay (IP or
LR/Stability).
6
The attribute is monitored directly, collectively, or via a surrogate assay
ONLY during “Comparability and Monitoring” testing.
10
No testing
LR  Lot release; IP  In-Process.
Robustness Assessment for Afucosylation: Glycan Assay
Attribute
Afucosylation
ATS
Score
Testing
Strategy
DS
Process
200
Control
System
DP
Process
20
No testing
DS
Stability
20
No testing
DP
Stability
20
No testing
Process
Test
Method
CE Glycan
Assay
Testing
Strategy
Score
Robustness AssessScore
ment
2
400
10
200
Robust
10
200
10
200
ATS  Attribute Testing Strategy; CE  capillary electrophoresis; DP  Drug Product; DS  Drug
Substance.
• Control of afucosylation by CE-glycan assay is ROBUST
Robustness Assessment for Afucosylation: ADCC
Potency Assay
Attribute
Afucosylation
ATS
Score
Testing
Strategy
DS
Process
200
Control
System
DP
Process
20
No testing
DS
Stability
20
No testing
DP
Stability
20
No testing
Process
Test
Method
ADCC
Potency
Testing
Strategy
Score
Robustness AssessScore
ment
4
800
10
200
10
200
10
200
Not
Robust
Robust
ATS  Attribute Testing Strategy; CE  capillary electrophoresis; DP  Drug Product; DS  Drug
Substance.
• Control of afucosylation by ADCC potency assay is
NOT ROBUST
• high impact CQA
• low process control
Robustness Assessment: Size Variants
Attribute
Aggregates
Fragments
ATS
Process Score
Testing
Strategy
DS
Process
48
DP
Process
24
DS
Stability
24
DP
Stability
24
DS
Process
12
No testing
DP
Process
12
No testing
DS
Stability
24
Comparability
and Monitoring
DP
Stability
48
Control System
Test Method
Testing
Strategy
Score
Robustness
Score
Assessment
288
Comparability
Size-Exclusion
and Monitoring Chromatography
144
6
Robust
144
144
Size-Exclusion
Chromatography
10
120
10
120
Robust
6
144
2
96
ATS  Attribute Testing Strategy; DP  Drug Product; DS  Drug Substance.
Proposed Control System for MAb 1: Drug Product
In-Process Testing
Attribute
Test Name
Sterility
Product Sterility Test (USP method)
Bioburden
Bioburden Testing of In-Process Samples
Endotoxin
Standard Procedure for limulus
Amebocyte Lysate (LAL) Assay
pH
pH
a
Osmolality
Osmolality
Polysorbate 20
Polysorbate Content
Protein Concentration
UV Spec Scan Using Gravimetric Sample
Preparation
CFU  colony forming unit; UV  ultraviolet visible.
a
direct measure of osmolality, indirect measure of excipient
concentrations
Proposed Control System for MAb 1: Drug Product
Lot Release and Stability
Attribute
Test Name
Identity
CZE
Appearance
COC
Acidic Variants
Size Variants
a
IEC
a
SEC
Subvisible Particulates
a
Particulate Analysis
Endotoxin (LAL)
Endotoxin (LAL)
Sterility
Sterility
a
Sterility
Dye Leak Test
a
Biological Activity
CDC Potency
Fill Volume
Volume in Container
CDC  complement-dependent cytotoxicity; COC  clarity, opalescence, and coloration;
CZE  capillary zone electrophoresis; IEC  ion-exchange chromatography; LAL  limulus
amebocyte lysate; SEC  size-exclusion chromatography.
a
Tests that will be performed on stability.
Comparability and Monitoring Testing: Drug Product
Attribute
Robustness Score
Detection by Control System
Assay for Drug Product?
Acidc Variants
288
CDC Potency Assay
Oxidation
384
CDC Potency Assay
Proposed Control System: MAb 1 Drug Substance
In Process Testing
Attribute
Mycoplasma
Test Name
Mycoplasma detection, culture method
Mycoplasma detection, indicator cell/DNAF
procedure
Virus
General Viral Screening Assay
Rodent Parvovirus PCR
Bioburden
Bioburden
Endotoxin
Endotoxin (LAL)
Afucosylation
(%G0
CE-Glycan
pH
pH
a
Osmolality
Osmolality
Polysorbate 20
Polysorbate Content
Protein
Concentration
UV Spec Scan
CE = capillary electrophoresis.
a Direct measure of osmolality,
indirect measure of excipient
concentrations
Proposed Control System: Drug Substance
Lot Release and Stability
Attribute
Test Name
Identity
Peptide Map
Acidic variants
Ion-Exchange Chromatography
Endotoxin (LAL)
Endotoxin (LAL)
Sterility
Sterility
a
Biological Activity
a
CDC Potency
Test will be performed on stability.
Comparability and/or Monitoring Testing: Drug Substance
Attribute
Fragments (stability)
Robustness Score
a
Acidic Variants (stability)
a
Detection by Control System
Assay for Drug Substance?
240 (240)
CDC Potency Assay, IEC
(240)
CDC Potency Assay, IEC
CHOP
240
No
Reduced MAb
384
CDC Potency Assay
Leached Protein A
192
No
Glycan Distribution
288
CE-Glycan Assay
Non-glycosylated Heavy Chain
144
CDC Potency Assay
DNA
144
No
Aggregates
144
CDC Potency
Protein Conformation
240
CDC Potency, IEC
Approach Applied to a Second MAb
• MAb 2 Background
• Binds to and blocks receptor on cell; effector function not
required for MOA
• Oncology indication
• Molecule is exceptionally stable; forced degradation
studies cannot generate deamidation, oxidation, or
glycation of CDR sites
– Limited number of CQAs requiring control
– Therefore, limited number of CPPs to constrain Design Space
MAb 2 Proposed Control System
Drug Substance CoA/Stability
Attribute
Test Name
Identity
Peptide Map
Endotoxin (LAL)
Endotoxin (LAL)
Sterility
Sterility
a
Biological Activity
Potency
Drug Product CoA/Stability
Attribute
Test Name
Identity
CZE
Appearance
COC
Size Variants
a
SEC
Subvisible Particulates
a
Particulate Analysis
Endotoxin (LAL)
Endotoxin (LAL)
Sterility
Sterility
a
Sterility
Dye Leak Test
a
Biological Activity
Potency
Fill Volume
Volume in Container
Summary
• Risk-based tools developed to define Testing Strategy and Control
System
• Utilizes knowledge of
– CQA Impact on potency, immunogenicity, safety, and PK/PD
– Process Impact
– Stability Impact
– Specificity and Sensitivity of analytical method
• Assigns attributes to three categories of testing
– Control System (Lot release, stability, in-process)
– “Comparability and Monitoring”
– No testing
• Robustness assessment for control of CQAs
– Iterative process
– Evaluates risk that control strategy is insufficient
Summary, continued…
• Use of filters in assessment of testing strategy
• Abundance filter as part of Process Impact, not CQA ID
• Default process impact score for low impact quality attributes
– Balances wide CQA Acceptance Criteria with potentially little process
impact knowledge
Advantages of the QbD Approach to Developing a
Control Strategy
• Clear, logical approach – applicable to all types of biologics
• Control Strategy development relies on significant process and product
knowledge
• Clear rationale for selection of attributes to test and the type of testing
strategy applied can lead to streamlined Control System testing
• Understanding impact of each process step to CQA levels leads to
targeted testing for comparability
– Only test those attributes impacted by changed steps
Acknowledgements
Jerry Dong
Lynn Gennaro
Yung-Hsiang Kao
Paramjit Kaur
Daniel Kelati
Brian Kelley
Lynne Krummen
Reed Harris
Kathy Hsia
Raquel Iverson
Kim Latimer
Nadja Alt (Roche)
Bernd Hilger (Roche)
Joseph Marhoul
Nathan McKnight
Paul Motchnik
Dave Reifsnyder
Sofia Ribeiro
Natalie Saldou-Holtz
Cristina Sanchez
Dieter Schmalzing
Ron Taticek
Pin-Yee Wong
Rita Wong
MAb 1: Attributes that Require No Testing for Drug
Substance
Attribute
Fragments (stability)
Robustness Score
a
Acidic Variants (stability)
a
Detection by Control System
Assay for Drug Substance?
240 (240)
CDC Potency Assay, IEC
(240)
CDC Potency Assay, IEC
CHOP
240
No
Reduced MAb
384
CDC Potency Assay
Leached Protein A
192
No
Glycan Distribution
288
CE-Glycan Assay
Non-glycosylated Heavy Chain
144
CDC Potency Assay
DNA
144
No
Aggregates
144
CDC Potency
Protein Conformation
240
CDC Potency, IEC
MAb 1: DS Testing Strategy for All Attributes
Control System Testing
Attribute
Assay
In-Process
Lot Release Stability
Process
No
Monitoring and
Comparability Testing
Product-Related Variants
Afucosylated
glycans
CE-glycan
X
Glycan distribution
CE-glycan
X
Fragments
SEC
X
Aggregates
SEC
X
Acidic variants
IEC
Non-glycosylated
heavy chain
CE-SDS
Oxidation (Trp and
Met)
CDC Potency
Reduced MAb
CE-SDS (NR)
X
X
X
X
X (stability)
X
Protein
Conformation
X
Cys22-Cys96 free
thiol
X
N-terminal extension IEC
X
C-terminal variants
X
CZE
Non-functional
IEC
Region Deamidation
X
Non-functional
Region glycation
X
IEC
MAb 1: DS Testing Strategy for All Attributes,
cont’d
Control System Testing
Attribute
Assay
In-Process
Lot
Release
Stability
Process
No
Monitoring and
Comparability Testing
Statutory Requirements/Stability-Impacting Attributes
Identity
Peptide Map
X
Protein
Concentration
UV Spec Scan
X
Osmolality
Osmolality
X
pH
pH
X
Acetate
Concentration
Osmolality
X
Trehalose
Concentration
Osmolality
X
Polysorbate
Concentration
Polysorbate
20 Content
X
Process Related Impurities
Mycoplasma
X
Rodent Parvovirus
X
CHOP
X
Leached Protein A
X
DNA
X
Bioburden
Bioburden
X
X
X
Endotoxin
LAL
X
X
X
Cell Culture and
Purification Raw
Materials
NMR, ICP
X
Leachables
GC-MS
X