Bispecific Ab characterization
Aspects for BsAb evaluation
Fab Region
Fab Region
MOA: Fab region binds to target
MOA: Fab region binds to target
antigen
antigen
Dual target blockade/
In cis cell surface
In trans cell bridging assay
T cell engager
modulatory assay
protein bridging assay
Blocking angiogenesis and/or
tumorigenesis
Apoptotic signaling pathway
Coagulation pathway
NK cell engager
Modulating tumor microenvironment
(TME)
Anti-TAA x co-stimulatory
immune checkpoint
Targeting inflammatory/autoimmune
diseases
Anti-TAA x co-inhibitory
immune checkpoint
Blocking angiogenesis and/or
tumorigenesis x Anti-immune
checkpoint
ADC characterization
Aspects for ADC evaluation
Fab Region
Payload
MOA: Fab region binds to target
antigen, triggering endocytosis
Cell based assay: antibody
internalization assay
MOA: a cell-killing cytotoxic drug
conjugated in Ab, inducing target
cell death
Cell based assay: cytotoxicity assay
Antibody internalization assay
Cytotoxicity assay
By-stander effect
Antigen-mediated internalization is a
critical characteristic of ADC
candidates.
Cytotoxicity assays,
Bystander cell is the surround-
ing cell of tumor, which could
be Ag+ or Ag-. When the tumor
cell is lysed, the uptaken toxin
will be released to kill neighbor-
ing cells.
measuring the killing
potential of ADCs are a
necessary first step to triage
CellTiter-Glo®
CCK8
Live-cell imaging based internalization
pH-indicator based internalization
Toxin-conjugated mAb based
cytotoxicity assay DT3C/VHH-DT
/FabFc-ZAP
Medium transfer or co-culture
assay using live cell imaging or
Flow cytometry
LDH
Luminescence/fluores-
cence-based
Temperature shift based internalization
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