Processes for Preparing a Polypeptide

Abstract

The present invention relates to an improved process for preparing a polypeptide or pharmaceutically acceptable salt thereof comprising L-tyrosine, L-alanine, L-glutamate, and L-lysine. The polypeptide or pharmaceutically acceptable salt thereof is preferably glatiramer acetate. The process comprises: (a) polymerizing a mixture of N-carboxyanhydride of L-tyrosine, N-carboxyanhydride of L-alanine, N-carboxyanhydride of a protected L-glutamate and N-carboxyanhydride of a protected L-lysine, in a polar aprotic solvent in the presence of an initiator, to form a protected polypeptide; (b) admixing an acid with the protected polypeptide formed in Step (a) and a solvent, to form a product; and (c) admixing a substance selected from the group consisting of an alkali or alkaline earth metal hydroxide, a carbonate, a hydrogencarbonate, and mixtures thereof, with the product formed in Step (b), and a solvent or a mixture of a solvent and water, to form a deprotected polypeptide or a pharmaceuticaly acceptable salt thereof.

1 - 62 . (canceled) 
   
   
       63 . A process for preparing a polypeptide comprising L-tyrosine, L-alanine, L-glutamate and L-lysine, or a pharmaceutically acceptable salt thereof, wherein said process comprises:
 (a) polymerizing a mixture of N-carboxyanhydride of L-tyrosine, N-carboxyanhydride of L-alanine, N-carboxyanhydride of a protected L-glutamate and N-carboxyanhydride of a protected L-lysine, in a polar aprotic solvent in the presence of an initiator, to form a protected polypeptide;   (b) admixing an acid with the protected polypeptide formed in Step (a) and a solvent, to form a product; and   (c) admixing a substance selected from the group consisting of an alkali or alkaline earth metal hydroxide, a carbonate, a hydrogencarbonate, and mixtures thereof, with the product formed in Step (b), and a solvent or a mixture of a solvent and water, to form a deprotected polypeptide or a pharmaceutically acceptable salt thereof.   
   
   
       64 . A process for preparing a polypeptide comprising L-tyrosine, L-alanine, L-glutamate and L-lysine, or a pharmaceutically acceptable salt thereof, wherein said process comprises:
 (a) polymerizing a mixture of N-carboxyanhydride of L-tyrosine, N-carboxyanhydride of L-alanine, N-carboxyanhydride of a protected L-glutamate and N-carboxyanhydride of a protected L-lysine, in a polar aprotic solvent in the presence of an initiator, to form a protected polypeptide;   (b) admixing an acid with a mixture comprising the protected polypeptide formed in Step (a) and a solvent, to form a product; and   (c) admixing a substance selected from the group consisting of an alkali or alkaline earth metal hydroxide, a carbonate, a hydrogencarbonate, and mixtures thereof, with the product formed in Step (b), and a solvent or a mixture of a solvent and water, to form a deprotected polypeptide or a pharmaceutically acceptable salt thereof.   
   
   
       65 . The process according to  claim 63 , wherein the protected L-lysine is N ε -trifluoroacetyl L-lysine. 
   
   
       66 . The process according to  claim 63 , wherein the protected L-glutamate is selected from the group consisting of γ-ρ-methoxybenzyl L-glutamate, γ-benzyl L-glutamate and mixtures thereof. 
   
   
       67 . A process for preparing glatiramer acetate comprising:
 (a) polymerizing a mixture of N-carboxyanhydride of L-tyrosine, N-carboxyanhydride of L-alanine, N-carboxyanhydride of a protected L-glutamate and N-carboxyanhydride of N ε -trifluoroacetyl L-lysine, in a polar aprotic solvent in the presence of an initiator, to form a protected glatiramer, wherein said protected L-glutamate is selected from the group consisting of γ-ρ-methoxybenzyl L-glutamate, γ-benzyl L-glutamate and mixtures thereof;   (b) admixing an acid with a mixture comprising the protected glatiramer formed in Step (a) and a solvent, to form a product;   (c) admixing a substance selected from the group consisting of an alkali or alkaline earth metal hydroxide, a carbonate, a hydrogencarbonate, and mixtures thereof, with a mixture comprising the product formed in Step (b), and a solvent or a mixture of a solvent and water, to form a deprotected glatiramer; and   (d) treating the deprotected glatiramer formed in Step (c) with acetic acid to form glatiramer acetate.   
   
   
       68 . The process according to  claim 63 , wherein the solvent used in Step (b) is selected from the group consisting of polar protic solvents, polar aprotic solvents and mixtures thereof. 
   
   
       69 . The process according to  claim 68 , wherein the solvent is selected from the group consisting of acetic acid, tetrahydrofuran, ethyl acetate, dimethyl furan, dimethylformamide, 1,4-dioxane, dimethoxyethane, 1,2-dichloroethylene, dimethylsulfoxide and dichloromethane. 
   
   
       70 . The process according to  claim 69 , wherein the solvent is tetrahydrofuran. 
   
   
       71 . The process according to  claim 69 , wherein the solvent is acetic acid. 
   
   
       72 . The process according to  claim 63 , wherein the substance selected from the group consisting of an alkali or alkaline earth metal hydroxide, a carbonate, a hydrogencarbonate, and mixtures thereof, is present in an amount of from about 0.1 wt. % to about 10 wt. %, based on the total weight of solvent or mixture of a solvent and water, which is used in Step (c). 
   
   
       73 . The process according to  claim 72  wherein the substance selected from the group consisting of an alkali or alkaline earth metal hydroxide, a carbonate, a hydrogencarbonate and mixtures thereof, is present in an amount of from about 0.1 wt. % to about 5 wt. %, based on the total weight of solvent or mixture of a solvent and water, which is used in Step(c). 
   
   
       74 . The process according to  claim 63 , wherein the solvent or mixture of a solvent and water, which is used in Step (c), is present in an amount from about 1-fold (wt.) to about 1000-fold (wt.), based on the total weight of the product of Step (b), which is used in Step (c). 
   
   
       75 . The process according to  claim 74 , wherein the solvent or mixture of a solvent and water, which is used in Step (c), is present in an amount from about 10-fold (wt.) to about 500-fold (wt.), based on the total weight of the product of Step (b), which is used in Step (c). 
   
   
       76 . The process according to  claim 63 , wherein the substance selected from the group consisting of an alkali or alkaline earth metal hydroxide, a carbonate, a hydrogencarbonate and mixtures thereof, is selected from the group consisting of calcium hydroxide, lithium hydroxide, magnesium hydroxide, potassium hydroxide, barium hydroxide, sodium hydroxide, calcium carbonate, lithium carbonate, magnesium carbonate, potassium carbonate, sodium carbonate, calcium hydrogencarbonate, lithium hydrogencarbonate, magnesium hydrogencarbonate, potassium hydrogencarbonate and sodium hydrogencarbonate. 
   
   
       77 . The process according to  claim 76 , wherein the substance is selected from the group consisting of sodium hydroxide, lithium hydroxide and potassium hydroxide.