Current Approaches for ADME Characterization of Antibody

25 Pages·2016·1.33 MB·English

by  Sweigart, Kathryn R.

Current Approaches for
2016 IQ Webinar Series Presents:
ADME Characterization of
Antibody-Drug Conjugates
Sponsored by the IQ Drug Metabolism Leadership Group

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Current Approaches for ADME Characterization of
Antibody-Drug Conjugates
IQ- ADC ADME Working Group
Feb 19, 2016
Team members:
• Eugenia Kraynov (Team Lead) – Pfizer • Priya Sriraman – Celgene
• Amrita Kamath – Genentech • Michaela Bairlein – Bayer
• Markus Walles – Novartis • Johnny Yang – Takeda
• Edit Tarcsa – Abbvie • Matthew Barfield – GlaxoSmithKline
• Nagendra Chemuturi – Seattle Genetics • Guangqing Xiao – Biogen
• Antoine Deslandes – Sanofi • Enrique Escandon – Merck
• Ramaswamy Iyer – Bristol-Myers Squibb • Weirong Wang – Jansen
• Amita Datta-Mannan – Eli Lilly • David Moore – Roche
• Dan Rock – Amgen
Current Approaches for ADME Characterization of Antibody-Drug Conjugates: An
Industry White Paper. Kraynov et al, Drug Metabolism & Disposition, December 2015
Outline
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• Overview of ADC PK
– Nomenclature/Definitions
– Mechanisms of disposition
– Bioanalytical considerations
– Factors impacting PK of ADCs

• Currents approaches to characterize ADC ADME
– In vitro and In vivo studies
– Novel vs. previously used payloads

• Summary and Overall recommendations

Current Approaches for ADME Characterization of Antibody-Drug Conjugates: An
Industry White Paper. Kraynov et al, Drug Metabolism & Disposition, December 2015
ADC Components

DRUG
ANTIBODY LINKER
‘payload’, ‘warhead’, ‘toxin’
• mAbs • Cleavable • Tubulin polymerization inhibitors
• ThioMAbs • Peptide • maytansines (DM1, DM4)
• Disulfide • auristatins (MMAE, MMAF)
• Acid-labile • DNA damaging agents
• Non-Cleavable • calicheamicin, duocarmycin
• Thioether • doxorubicin

DAR: Drug Antibody Ratio, i.e., number of drugs per antibody
ADC Antibody Formats 5
ADC: Conjugation through ADC: Conjugation through reduced Thiomab™; TDC: Conjugation through
Lysine residues inter-chain disulfide bonds engineered cysteine residues
DAR DAR DAR
DAR = Drug-Antibody Ratio
Panowski, et al. mAbs 2014
ADC: Mechanism of Disposition
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Receptor-mediated Endocytosis
Non-Specific
Pinocytosis
Endosome
Drug Release in Lysosome
Endosome
Linker Cleavage
Metabolism of
released drug
Lysosome
Metabolite of released Drug release by
linker proteolysis
drug in systemic
or whole ADC
circulation or bile
catabolism
(from hepatocyte) Catabolism
Unconjugated drug in systemic
circulation, extracellular space, or bile
(from hepatocyte)
PK of ADC: What to Measure?
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Heterogeneous mixture of different DARs Additional complexity generated in vivo
Unconjugated
drug
DAR 2 DAR 1 DAR 0
Conjugated antibody/ Antibody-conjugated Drug
Total Antibody
 Multiple bioanalytical assays (ELISA, LC/MS)
Affinity-Capture LC/MS (Exploratory):
Stability & Biotransformation
Kaur et al, Bioanalysis, 2013; Kamath & Iyer, Pharm Res, 2015; Xu et al, Anal Biochem 2011
Impact of ADC components on PK
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Antibody Linker
Solid line = Total antibody

Dotted Line = Conjugated antibody
Naked antibody
Total antibody
after dosing ADC
Mouse T-SMCC-DM1 had
better efficacy &
toleratibility than
T-SPP-DM1
Lin & Tibbitts, Pharm Res (2012) Erickson et al, Mol Cancer Ther (2012)
Conjugation Site Drug Load (DAR)
Closed symbols= Total antibody
Open symbols = Conjugated antibody
LC, HC, Fc Tabs )
L Total antibody analyte
m
g/
μ
(
s
LC-TDC c
n Unconjugated Ab
o
HC-TDC C DAR 2
b DAR 4
a
Fc-TDC T
Mouse Mouse
DAR 8
Time (Days)
Efficacy: LC-V205C > HC-A114C > Fc-S396C Higher DAR species associated with
faster clearance & increased toxicity
Shen et al, Nat Biotech (2012) Hamblett et al, Clin Can Res (2004)
Example of Impact of Linker Type on Catabolite Profile
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• Different intracellular processing of toxin/linker constructs and different metabolites result in
different bystander killing activity
Non reducible/Non-cleavable
Reducible/Cleavable
No bystander effect
• SPDB linker was processed into
lipophilic metabolites (which had
bystander effects)
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Erickson et al. Cancer Res (2006)
bystander effect
Erickson et al, Bioconj Chem (2010)
(100,000X lysine–Ne-MCC-DM1)
ADC PK/ADME: Key Assessments 10
ADC Stability
Types of Assessments
• In Vitro Study
• Linker stability
– Plasma or Serum from human and efficacy & tox species
– What is optimal stability for efficacy/toxicity? – Incubation conditions
– Should be stable in circulation, but promptly – 37ºC at pH 7.4 for 96 hours
release the drug in the target cells – ADC concentration around observed/predicted Cmax in
animal species or human
– Typical analytes: Tab, conjugate, released drug, DAR
• Catabolite/Metabolite ID
– Can help optimize the combination of mAb, linker & drug
– What is released? Is it active?
– Does it accumulate in tissues/tumor?
In Vivo PK
– How it is eliminated?
Choice of animal species for ADC, same general principles as mAb
– Is it clinically relevant?
• Ideal if cross-reactive in animal species (i.e., binding species)

– If not cross-reactive, PK & toxicity may not be reflective of humans.
• In vivo exposure (efficacy & tox)
May still provide some information on non-specific disposition of
– Exposure-response analysis ADCs and on potential drug-related metabolites
– What is the driver of efficacy/toxicity?
– Which analyte correlates with activity? • Important to choose species that has similar in vivo fate/
deconjugation mechanism as in humans
– Plasma conc? Or tissue concs?

• PK characterization at doses low enough to evaluate target
• Other assessments
mediated clearance and high enough to understand toxicokinetics
– Drug-drug interactions
̶ Typical PK analytes: Tab, conjugate, released drug, DAR
– Immunogenicity