Download mAb-1 Mono

Considerations and Potential Impact of Biologic
Combination Therapy on Immunogenicity- A Preclinical
Case Study
AAPS-NBC 2014
Lakshmi Amaravadi, Ph.D.
Outline
v Combination Biologic Therapies- Emerging area
Ø  Physiological impact and Analytical considerations
v A preclinical case study example
v Unexpected Impact on Immunogenicity in the combination
setting
Ø  PK assays and investigation
Ø  Immunogenicity Assays and investigation
v Summary & Conclusions
2
Combination Biologic Therapies
v Complex metabolic diseases that involve multiple pathways
Ø  (RA, MS, Oncology…etc.)
v Combination therapies to achieve maximal efficacy
v Oncology setting: combination of a biologic with
SOC small molecule therapy is well known
v RA: combination of etanercept, infliximab, adalimumab
with MTX etc.
v During clinical development phase: precise measurement
of both molecules and an understanding of assays used to
measure them is necessary to interpret the data.
3
Small Molecule vs Biologic Combinations
and Analytic Considerations
v Drug: Drug interactions (small molecules)- competing
pathways involved in clearance mechanisms
v Combination of large and small molecule
considerations
Ø  Small molecules (<500D) vs large molecules (>5-150kD)
Ø  Half life differences: hours vs 4-5 weeks (for typical
mAbs)
Ø  Impact on biomarkers that may modify drug metabolism
v Emerging paradigm of combination biologics:
Ø  Potential for long half-life of both molecules
Ø  Physiological impact: possible synergies or additive effects
Ø  Analytical impact: important to understand for the
interpretation of data
4
Case Study: Combination Biologics
(A Preclinical Study)
v Therapeutic: Combination of humanized mabs (mAb1
and mAb2)
Ø  Drug in development mAb1 combined with mAb2 (a marketed
therapeutic)
v Disease Indication: Autoimmune Condition
v Immunogenicity risk: Relatively Low
Ø  Minimal antibody response detected in multiple species: Rat,
Cyno and human Phase 1 studies conducted with monotherapy
v 13 week Cyno Tox Study: to evaluate potential for
additive or synergistic toxicity of mAb-1 and mAb-2 in
combination
Preclinical Cyno Study Design
(13-Week Tox Study)
Dose Group
Dosing Level
(mg/kg)
Regimen
Vehicle Control
0
Weekly IV bolus injection
Weekly SC injection
mAb-1 Mono-therapy
10
Weekly IV bolus injection
mAb-2 Mono-therapy
2
Weekly SC injection
mAb-1 + mAb-2 Combination
Therapy (Combo)
10
2
Weekly IV bolus injection (mAb-1)
Weekly SC Injection (mAb-2)
Exposure and ADA response monitored by sparse sampling
Properties of the Two Biologics
Features
mAb-1
mAb-2
Classification
Fully Humanized mAb
(IgG1)
Fully Humanized mAb
(IgG1)
Soluble Ligand A
Soluble Ligand B
10 mpk/ weekly/IV
2 mpk/weekly/SC
Target/Agonist
Dose/Administration/
Route
Predicted Cmax
mAb-1 Cmax 10X > mAb-2 Cmax
IV= intravenous; SC-Subcutaneous
PK Assay Format: mAb-1
Color
Development
SA--HRP
mAb-1
Biotin anti Human
IgG1 Fc
Anti-mAb-1 Idiotype
•  Measures Free drug
•  Validated assay range- 1-40ug/mL
PK Assay Format: mAb-2
Color
Development
SA--HRP
mAb-2
Biotin anti Human
IgG1 Fc
Soluble Target
•  Measures Free Drug
•  Validated assay range- 0.1-10ug/mL
PK Assay Specificity for mAb-2
Nominal
concentration of
mAb-1 (ug/mL)
50
100
200
300
400
500
600
700
Molar
excess of
mAb-1
Nominal
concentration
of mAb-2 (ug/
mL)
Measured
Concentration
of mAb-2
(ug/mL)
Recovery of
mAb-2
(% theoretical)
500
1000
2000
3000
4000
5000
6000
7000
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
107.3
99.2
97.3
97.7
106.1
113.7
93.0
98.6
107
99
97
98
106
114
93
99
Ø  mAb-2 PK assay was determined to be specific and can accurately and
selectively measure mAb-2 in the presence of excess mAb-1
(near predicted Cmax and above).
PK Assay Specificity for mAb-1
Nominal
concentration
of mAb-2 (ug/
mL)
Molar
excess
mAb-2
Nominal
Measured
concentration Concentration
of mAb-1 (ug/ of mAb-1 (ug/
mL)
mL)
20
10
2
2.16
108%
150
75
2
2.10
105%
Recovery of
mAb-1 (%
theoretical)
Ø  mAb-1 PK assay was determined to be specific and can accurately and
selectively measure mAb-1 in the presence of excess mAb-2.
Immunogenicity Assay
(mAb-1)
Color
Development
SA--HRP
SA--HRP
Biotin mAb-1
mAb-1 ADA
mAb-1
•  Detects both anti-CDR and anti-frame work
directed antibodies.
•  Sensitivity: 15.6ng/mL, drug tolerance: 8:1
Exposure to mAb-1 in the Cyno Study
m A b -1 E x p o s u re
1000
m A b -1 m o n o th e ra p y (A D A n e g )
g /m L )
100
C o m b o (A D A p o s)
10
(
m A b -1 C o n c .
C o m b o (A D A n e g )
1
0 .1
D ay 1
D ay 29
D ay 57
D ay 86
•  Exposure to mAb-1 in the monotherapy group followed expected profile
•  There was an impact on exposure to mAb-1 in the combo therapy group (in
the ADA positive group)
mAb-1: Exposure Levels by ADA Status
mAb-1 Mono
(ADA neg)
mAb-1 Mono
(ADA pos)
Mean
N
Conc.
Combo
(ADA neg)
Mean
N
Conc.
Mean Conc.
N
Day 1
243 ± 20.1
8
NA
0
302 ± 57.1
Day 29
215 ± 44.0
8
NA
0
Day 57
225 ± 52.0
8
NA
Day 86
417 ± 155
8
NA
Combo
(ADA pos)
Mean Conc.
N
12
NA
0
171 ± 58.0
10
4.05 ± 0.42
2
0
180 ± 44.6
9
0.45 ± 0.77
3
0
261 ± 195
9
4.73 ± 4.50
3
N= number of animals, NA = not applicable, Combo= combination therapy
Dose groups were categorized as being positive (ADA pos) or negative (ADA neg) for anti-mAb1 antibodies
•  Exposure to mAb-1 in the ADA positive combo therapy group was remarkably reduced
Exposure to mAb-2 in the Cyno Study
m A b -2 E x p o s u re
100
m A b -2 m o n o th e ra p y (A D A n e g )
C o m b o (A D A p o s)
g /m L )
10
(
m A b -2 C o n c
C o m b o (A D A n e g )
1
0 .1
D ay 1
D ay 29
D ay 57
D ay 86
All mAb-2 mono-therapy samples at days 29, 57 and 86 were mAb-1 ADA positive and
therefore exposure levels measured below the limits of quantitation.
•  mAb-2 con. levels fell below the limit of detection as the study progressed in the
Monotherapy group. Exposure was retained in the combination group.
mAb-2: Exposure Levels by ADA Status
mAb-2 Mono
(ADA neg)
Mean Conc. N
mAb-2 Mono
(ADA pos)
Mean Conc. N
Combo
(ADA neg)
Mean Conc. N
Combo
(ADA pos)
Mean Conc. N
Day 1
11.7 ± 1.82
8
NA
0
11.65 ± 1.14
12
NA
0
Day 29
BLQ
2
BLQ
6
9.35 ±10.8
10
0.39 ± 0.06
2
Day 57
BLQ
1
BLQ
7
12.6 ± 13.0
9
0.15 ± 0.25
3
Day 86
BLQ
2
BLQ
6
18.2 ± 15.4
9
0.36 ± 0.62
3
N= number of animals, NA = not applicable, BLQ = below limits of quantitation
Dose groups were categorized as being positive (ADA pos) or negative (ADA neg) for anti-mAb-1 antibodies
• 
• 
In the combination group exposure to mAb-2 was maintained in the mAb-1 ADA negative group
mAb-2 con. was also detectable in the mAb-1 ADA positive group in the combination setting
Characterization of ADA Response
v  Competition assays performed to further characterize ADAs
Ø  mAb-1, mAb-2, mAb-X (common framework)
Assay
mAb-1 monotherapy
mAb-2 monotherapy
Combination
mAb-1 ADA screening assay
(% positive on Day 57)
Negative
(0%)
Positive
(88%)
Positive
(25%)
ADA Confirmed by
NA
mAb-1, mAb-2,
mAb-X
mAb-1
ADA Characterization
NA
Anti-framework
Anti-CDR
Ø  mAb-2 monotherapy resulted in predominantly anti-frame work antibodies
Ø  Combination group predominantly exhibited anti-CDR response to mAb-1
Summary
v mAb-1 monotherapy did not exhibit immunogenicity in
several species
v In combination with mAb-2 unexpected immunogenicity was
observed against mAb-1
v ADAs detected in the combination group were primarily
CDR directed
v Impact on drug exposure was observed due to
immunogenicity in the case of both mAb-1 and mAb-2 in
combination setting
v What does this mean for risk assessment of
immunogenicity in combination settings?
Conclusions
v  Unique response (impact) can be observed in combination
therapy settings that is otherwise not present in monotherapy
setting
v  Direct vs indirect impact of combination therapies:
Ø  Small molecule settings
Ø  Small vs large molecule setting
Ø  Large molecule combinations
v  Impact on PK and activity of each other in the combination
setting could be altered
v  Appropriate and thorough understanding of analytical assays
required
v  Combination Biologics- an emerging area….more to come.
Acknowledgements
BiogenIdec
Kim Zinnack
Jean Donley
Lauren Stevenson
Lisa Beebe
Many members of TM and Toxicology
AAPS- LBABFG
Ref: Bioanalysis: 2011 Mar;3(5):487-98. doi: 10.4155/bio.10.214.
Paradigm of combination biologics: analytical challenges related to pharmacokinetic
assays and interpretation of pharmacokinetic and immunogenicity results.
Stevenson L, Zinnack K, Donley J, Beebe L, Amaravadi L.
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