US 11,860,156 B2
Bioanalytical analysis of site-specific antibody drug conjugates
Martine Darwish, San Francisco, CA (US); Surinder Kaur, Lafayette, CA (US); Dian Su, Redwood City, CA (US); and Keyang Xu, Belmont, CA (US)
Assigned to Genentech, Inc., South San Francisco, CA (US)
Filed by Genentech, Inc., South San Francisco, CA (US)
Filed on May 26, 2020, as Appl. No. 16/883,152.
Application 16/883,152 is a continuation of application No. 15/606,304, filed on May 26, 2017, abandoned.
Claims priority of provisional application 62/342,825, filed on May 27, 2016.
Prior Publication US 2021/0011000 A1, Jan. 14, 2021
Int. Cl. G01N 33/50 (2006.01); G01N 33/68 (2006.01); C12Q 1/37 (2006.01); A61K 38/02 (2006.01); A61K 39/395 (2006.01); G01N 33/53 (2006.01); C07K 14/00 (2006.01)
CPC G01N 33/5005 (2013.01) [A61K 38/02 (2013.01); A61K 39/395 (2013.01); C12Q 1/37 (2013.01); G01N 33/53 (2013.01); G01N 33/6848 (2013.01); G01N 33/6857 (2013.01); C07K 14/00 (2013.01)] 7 Claims
 
1. A method to detect and quantify antibody protein concentration and antibody-conjugated drug quantity in an antibody drug conjugate (ADC) comprising:
a. digesting the ADC bound via the Fab region to a target antigen-paramagnetic bead capture media, where the ADC comprises at least one drug moiety linked to an antibody at a recombinantly-engineered site cysteine amino acid residue in the Fab region with IdeS protease that cleaves the ADC, to remove the Fc fragment and form a digested ADC composition comprising at least one peptide fragment that is not linked to the at least one drug moiety, and at least one peptide fragment that is linked to the at least one drug moiety, wherein the digesting comprises incubating the ADC with the IdeS protease for a time period of 1 hour; and,
b. analyzing the digested ADC composition by a method comprising electrospray ionization liquid chromatography mass spectrometry.