Filterable duocarmycin-containing antibody-drug conjugate compositions and related methods
Duocarmycin-based antibody-drug conjugates can be readily separated from non-conjugated duocarmycin linker-drug in a composition that contains a solvent system of water and acetonitrile and that has 30% to 60% acetonitrile.
1. A method, which comprises:
(a) combining (i) an aqueous solution or a lyophilized product of an antibody-drug conjugate of formula (I):
Ab-(L-D) m (I),
wherein Ab is an IgG antibody, L-D is a duocarmycin linker-drug, wherein the duocarmycin linker-drug in non-conjugated form is represented by formula (IV):
wherein n is 0-3; R 5 is selected from
y is 1-16; and
R 6 is selected from
m represents an average DAR of from 1 to 12, and optionally further comprising the duocarmycin linker-drug in non-conjugated form, with (ii) a dilution medium that comprises water, acetonitrile, and acid to form a filterable composition, wherein said filterable composition comprises 30% to 60% (v/v) of said acetonitrile; and
(b) filtering said filterable composition across a filter having a molecular weight cutoff within the range of 3 kDa to 50 kDa to form a filtrate.
2. The method according to claim 1 , wherein said non-conjugated duocarmycin linker-drug is represented by the formula
3. The method according to claim 1 , wherein said filtrate is formed with less than 0.5% of the amount of said antibody-drug conjugate that was present in said filterable composition.
4. The method according to claim 3 , wherein said filtering is centrifugal filtering.
5. The method according to claim 4 , wherein said filter comprises a modified polyethersulfone filter media.
6. The method according to claim 1 , which further comprises subjecting said filtrate to a chromatographic separation process suitable for isolating said duocarmycin linker-drug in non-conjugated form and measuring the amount, if any, of said duocarmycin linker-drug in non-conjugated form present in said filtrate.
7. The method according to claim 1 , wherein said filterable composition comprises 35% to 55% of said acetonitrile.
8. The method according to claim 1 , wherein said antibody-drug conjugate is contained in a concentration of from 0.5 to 50 mg/ml.
9. The method according to claim 8 , wherein said antibody-drug conjugate is contained in a concentration of from 1.0 to 10 mg/ml.
10. The method according to claim 1 , wherein said acid in said filterable composition has a concentration of from 0.05% to 2%.
11. The method according to claim 10 , wherein said acid in said filterable composition has a concentration of from 0.1% to 1%.
12. The method according to claim 11 , wherein said acid is selected from the group consisting of trifluoroacetic acid, formic acid, and hydrochloric acid.
13. The method according to claim 9 , wherein said filtrate is formed with less than 0.2% of the amount of said antibody-drug conjugate that was present in said filterable composition.
14. The method according to claim 13 , wherein said filtrate is formed with less than 0.1% of the amount of said antibody-drug conjugate that was present in said filterable composition.
15. The method according to claim 1 , wherein said filter has a molecular weight cutoff within the range of 10 kDa to 30 kDa.