Method for determining the amount of a therapeutic antibody in the brain
Abstract
Herein is reported a method for determining the concentration of a therapeutic antibody in a tissue of an experimental animal to whom the therapeutic antibody had been administered, wherein the interference from residual blood in a tissue sample of the experimental animal, which is used for determining the concentration of the therapeutic antibody in said tissue, is reduced, wherein the concentration of the therapeutic antibody in the tissue of the experimental animal is calculated with the following formula:CtmAb,tissue=CtmAb,tissue,det.Ctissue,sample-CrefmAb,tissue,det.Ctissue,sampleCrefmAb,plasma.det.*CtmAb,plasma,det.wherein CtmAb,tissue,det.=obtained by determining the concentration of the therapeutic antibody in the tissue sample of the experimental animal, CtmAb,plasma,det.=obtained by determining the concentration of the therapeutic antibody in a blood sample of the experimental animal directly prior to taking the tissue sample, CrefmAb,tissue,det.=obtained by determining the concentration of the inert reference antibody in the tissue sample of the experimental animal, CrefmAb,plasma,det.=obtained by determining the concentration of an inert reference antibody in the blood sample of the experimental animal directly prior to taking the tissue sample, Ctissue,sampie=obtained by determining the tissue concentration in the tissue sample, whereby the inert reference antibody does not penetrate into said tissue, whereby the inert reference antibody is administered 2 to 10 minutes prior to obtaining the tissue and blood sample.
Claims
exact text as granted — not AI-modified1 . A method or assay for determining the concentration of a therapeutic antibody in a tissue of an experimental animal, whereby the tissue has a barrier to the blood circulation of said animal and whereby the therapeutic antibody had been administered to said experimental animal, wherein the interference from residual blood in a tissue sample of the experimental animal, which is used for determining the concentration of the therapeutic antibody in said tissue, is reduced, the method comprising the following steps
i) determining the concentration of the therapeutic antibody in a blood sample of the experimental animal, ii) determining the concentration of the therapeutic antibody in the tissue sample of the experimental animal, iii) determining the concentration of an inert reference antibody in the blood sample of the experimental animal, iv) determining the concentration of the inert reference antibody in the tissue sample of the experimental animal, v) determining the tissue concentration in the tissue sample, and determining the concentration of the therapeutic antibody in the tissue of the experimental animal with the following formula:
C
tmAb
,
tissue
=
C
t
m
A
b
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tissue
,
det
.
C
t
i
s
sue
,
sample
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C
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e
f
m
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b
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tissue
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det
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C
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sample
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refmAb
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*
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concentration
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concentration
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ii
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C
refmAb
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concentration
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concentration
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whereby the inert reference antibody does not cross said barrier between the tissue and the blood circulation,
whereby the inert reference antibody had been administered i) either together with the therapeutic antibody in case the sample is to be taken within 5 minutes after the administration of the therapeutic antibody, or ii) 2 to 10 minutes prior to taking the tissue sample,
whereby the blood sample is taken directly prior to the tissue sample.
2 . The Method according to claim 1 , wherein the tissue is either brain tissue and the therapeutic antibody can cross the blood-brain-barrier or ocular tissue and the therapeutic antibody can cross the blood-ocular-barrier.
3 . The method according to any one of claims 1 to 2 , wherein the therapeutic antibody is a bispecific antibody.
4 . The method according to any one of claims 1 to 3 , wherein the therapeutic antibody is specifically binding to human transferrin receptor and a brain target.
5 . The method according to claim 4 , wherein the brain target is human CD20 or human Abeta or human alpha-synuclein or human tau or human glucocerebrosidase or human lingo-1 or human huntingtin.
6 . The method according to any one of claims 1 to 5 , wherein the experimental animal is selected from mouse, rat, rabbit, dog, sheep, ape, and monkey.
7 . The method according to any one of claims 1 to 6 , wherein the experimental animal is a non-human experimental animal with a body weight of more than 100 g and less than 15 kg.
8 . The method according to any one of claims 1 to 7 , wherein the experimental animal is a cynomolgus monkey.
9 . The method according to any one of claims 1 to 8 , wherein the inert reference antibody is a human germline antibody.
10 . The method according to any one of claims 1 to 9 , wherein the inert reference antibody is DP47GS.
11 . The method according to any one of claims 1 to 10 , wherein the inert reference antibody does not cross said barrier in detectable amounts within 15 minutes after its application.
12 . The method according to claim 11 , wherein the inert reference antibody does not cross said barrier in detectable amounts within 10 minutes after its application.
13 . The method according to any one of claims 1 to 12 , wherein the inert antibody is administered about 5 minutes prior to taking the tissue sample.
14 . The method according to any one of claims 1 to 10 , wherein the tissue is perfused with an aqueous solution directly after taking the blood sample and prior to taking the tissue sample.
15 . The method according to any one of claims 1 to 11 , wherein the determining of the concentrations is by a bridging ELISA.Join the waitlist — get patent alerts
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