US 12,428,470 B2
Compositions containing activatable antibodies
Sarah Patrick, Menlo Park, CA (US); Claus Krebber, Palo Alto, CA (US); Sridhar Viswanathan, Menlo Park, CA (US); Shanti Gonela Duvur, Fremont, CA (US); and Eric Ureno, Daly City, CA (US)
Assigned to CytomX Therapeutics, Inc., South San Francisco, CA (US)
Filed by CytomX Therapeutics, Inc., South San Francisco, CA (US)
Filed on Apr. 9, 2021, as Appl. No. 17/227,029.
Claims priority of provisional application 63/007,776, filed on Apr. 9, 2020.
Prior Publication US 2021/0317188 A1, Oct. 14, 2021
Int. Cl. C07K 16/00 (2006.01); C07K 1/22 (2006.01); C07K 16/28 (2006.01)
CPC C07K 16/00 (2013.01) [C07K 1/22 (2013.01); C07K 16/2803 (2013.01); C07K 16/2818 (2013.01); C07K 16/2827 (2013.01)] 44 Claims
 
1. A method for determining or monitoring relative amounts of an activatable antibody and a clipped variant thereof during a composition production process, the method comprising:
a) subjecting a sample composition from each of two or more operations of an activatable antibody composition production process, wherein each sample composition comprises a population of activatable antibody and a population of clipped variants thereof, to a gel capillary electrophoresis procedure to thereby separate the population of activatable antibody from the population of clipped variants thereof in the gel capillary electrophoresis procedure, wherein the two or more operations of an activatable antibody composition production process are selected from the group consisting of a cell harvest, protein affinity chromatography, ion exchange chromatography, hydrophobic interaction chromatography, and multimodal chromatography; and
b) quantifying the relative amounts of the population of activatable antibody and the population of clipped variants thereof in each sample composition by determining the peak area corresponding to intact prodomain-containing polypeptide and the peak area corresponding to clipped prodomain-containing polypeptide(s) thereof to thereby monitor the relative amounts of the activatable antibody and the clipped variant thereof during the composition production process,
wherein the intact activatable antibody comprises (i) at least a first antigen binding domain (AB) that has a specific binding affinity for a first biological target, and (ii) a first prodomain,
wherein the at least first AB comprises a first antibody light variable domain (VL) and a first antibody heavy variable domain (VH),
wherein the first prodomain comprises a first masking moiety (MM) and a first cleavable moiety (CM),
wherein the first AB is coupled to the first prodomain,
wherein the clipped variant of the intact activatable antibody comprises the AB of the activatable antibody but lacks all or a portion of the MM.