Patent ID: 8859489
Filing Date: 2014-10-14
Classification: A61P,C07K

Abstract:
1. A method for preparing a composition comprising purified glatiramer acetate having a pyro-Glu concentration of 2000-7000 ppm and a Mp of 5000-9000 Da, comprising: polymerizing N-carboxy anhydrides of L-alanine, benzyl-protected L-glutamic acid, trifluoroacetic acid (TFA) protected L-lysine and L-tyrosine to generate a protected copolymer (Intermediate-1); treating the protected copolymer with HBr and acetic acid to partially depolymerize the protected copolymer and deprotect benzyl protected groups thereby generating a partially depolymerized product; treating the partially depolymerized product with piperidine to deprotect TFA-protected lysines thereby generating glatiramer acetate; and purifying the glatiramer acetate to create purified glatiramer acetate having a pyro-Glu concentration of 2000-7000 ppm and a Mp of 5000-9000 Da, wherein water is present during the entirety of the depolymerization step in an amount that yields glatiramer acetate having a pyro-Glu concentration of 2000-7000 ppm and a Mp of 5000-9000 Da.