Module 9 2021

22/03/2021

Non-cell-based neutralisation assays

Competitive ligand binding assay (CLBA) can be used if relevant to the MoA of the therapeutic (e.g., binding to a soluble ligand thereby blocking it from interacting with its receptor and inhibiting ligand bioactivity).

MSD platform - example

MSD platform – assay principle

NCB - adalimumab-treated patient

neutralising ADA - loss of signal

no ADA - signal

binding ADA - signal

300

Sulfo-tag labelled therapeutic, incubated with sample (control Ab, matrix)

200

T0 T3 T6

100

ECL counts

Target immobilised (soluble Rec, ligand,…)

0

10

30

90

270 810 2430

Alternative: target labelled with biotin & use of streptavidin plate

reciprocal dilution

Adalimumab-treated patient serum samples (T0, T3, T6), incubated with biotin TNF a and sulfo-tag adalimumab.

Dotted blue line indicates binding of biotin TNF a and sulfo- tag adalimumab in absence of serum sample

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Non-cell-based neutralisation assay – titer & matrix effect

Correlation coefficient r 2 =0.87

Non-cell based IL-17A neutralising antibody assay: inhibition of binding of sulfo-tag IL-17A to its cognate receptor by antibodies present in three APS1 sera (■,▼,▲). The dotted horizontal lines indicate the observed maximal binding (absence of IL-17A antibodies) and the corresponding 50% ECL count reading.

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