US 11,707,529 B2
Immunogenic glycoprotein conjugates
Jianxin Gu, Paramus, NJ (US); Rajesh Kumar Kainthan, Tappan, NY (US); Jin-Hwan Kim, Suffern, NY (US); Avvari Krishna Prasad, Chapel Hill, NC (US); and Yu-Ying Yang, Stamford, CT (US)
Assigned to Pfizer Inc., New York, NY (US)
Filed by Pfizer Inc., New York, NY (US)
Filed on Apr. 20, 2020, as Appl. No. 16/852,697.
Application 16/852,697 is a division of application No. 15/118,038, granted, now 10,668,164, previously published as PCT/IB2015/050919, filed on Feb. 6, 2015.
Claims priority of provisional application 61/939,845, filed on Feb. 14, 2014.
Prior Publication US 2020/0246475 A1, Aug. 6, 2020
Int. Cl. C07K 1/107 (2006.01); A61K 47/64 (2017.01); A61K 39/09 (2006.01); A61K 39/00 (2006.01)
CPC A61K 47/6415 (2017.08) [A61K 39/092 (2013.01); A61K 47/646 (2017.08); A61K 2039/6037 (2013.01); A61K 2039/627 (2013.01); C07K 1/1077 (2013.01)] 18 Claims
 
1. A method of making a glycoconjugate comprising a saccharide conjugated to a carrier protein through a (((2-oxoethyl)thio)alkyl)carbamate (oxo-eTAC) spacer, comprising the steps of:
(a) reacting a saccharide with a carbonic acid derivative or cyanogen derivative, to produce an activated saccharide;
(b) reacting the activated saccharide with L-cystine, mercaptopropionylhydrazide, 2-(2-aminoethoxy)ethane-1-thiol, or 4-Amino-1-butanethiol, or a salt thereof, to produce a thiolated saccharide;
(c) reacting the thiolated saccharide with a deprotecting or reducing agent to produce an activated thiolated saccharide comprising one or more free sulfhydryl residues;
(d) reacting the activated thiolated saccharide with an activated carrier protein comprising one or more α-haloacetamide groups, to produce a thiolated saccharide-carrier protein conjugate; and
(e) reacting the thiolated saccharide-carrier protein conjugate with:
(i) a first capping reagent capable of capping unconjugated α-haloacetamide groups of the activated carrier protein; and/or
(ii) a second capping reagent capable of capping unconjugated free sulfhydryl residues of the activated thiolated saccharide;
whereby an oxo-eTAC linked glycoconjugate is produced.