Purified capsular polysaccharides of Streptococcus pneumoniae
Inventors
Burki, Rajendar • Kandimalla, Vivek Babu • Sriraman, Rajan • Matur, Ramesh Venkat • Mantena, Narender Dev • Datla, Mahima • SANGAREDDY, VEERAPANDU
Assignees
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Publication Number
US-12465632-B2
Publication Date
2025-11-11
Expiration Date
Abstract
The invention relates to capsular polysaccharides of Streptococcus pneumoniae. More specifically, the present invention relates to sized and purified capsular polysaccharides of Streptococcus pneumoniae serotypes 2, 15A, 15C & 35B and process for their preparation.
Core Innovation
The invention relates to purified and mechanically or chemically sized capsular polysaccharides from Streptococcus pneumoniae serotypes 2, 15A, 15C and 35B, with an average molecular weight range of 50–10,000 kDa, and identification by NMR. For certain serotypes, the capsular polysaccharides are characterized by glycerol content and/or acetate content attributes, together with purity and impurity characteristics and sized polysaccharide profiles.
The sized capsular polysaccharides are linked to pneumococcal conjugate vaccine formulations as polysaccharide-protein conjugates produced by CDAP activation using 1-cyano-4-dimethylaminopyridine tetrafluoroborate. Conjugation kinetics are monitored, and the conjugate is characterized using SEC-MALLS and/or SEC-HPLC, with side-chain analysis described by HPAEC-PAD.
The conjugates are prepared with carrier proteins including PsaA, CRM197, PspA, and tetanus toxoid, and the vaccine composition comprises a protein/polysaccharide (w/w) ratio. The pneumococcal conjugate vaccine includes multivalent vaccine formulations such as 17-valent and 24-valent formulations, with formulation components including aluminum phosphate and saline, and rabbit immunogenicity assessment described using serotype-specific ELISA, including IgG titers and geometric mean fold rise (GMFR).
Claims Coverage
The independent claims cover two related aspects: a pneumococcal conjugate vaccine with CDAP-activated, purified serotype 35B capsular polysaccharides conjugated to PsaA under defined molecular-weight and protein/PS ratio constraints, and an immunogenic glycoconjugate composition that uses CDAP-activated purified serotype 35B capsular polysaccharides conjugated to PsaA under defined protein/PS and molecular-weight constraints.
CDAP-activated serotype 35B capsular polysaccharides conjugated to PsaA with defined conjugate molecular weight and protein/PS ratio
A pneumococcal conjugate vaccine comprising a 1-cyano-4-dimethylaminopyridine tetrafluoroborate (CDAP)-activated purified capsular polysaccharides from serotype 35B having an average molecular weight between 100 kDa and 500 kDa conjugated to PsaA, wherein the pneumococcal conjugate vaccine comprises a (w/w) percent ratio of protein to polysaccharide (protein/PS) of 0.7 to 1.2.
Immunogenic glycoconjugate composition with CDAP-activated serotype 35B polysaccharides conjugated to PsaA under defined protein/PS and glycoconjugate molecular weight ranges
An immunogenic composition comprising at least one glycoconjugate comprising a 1-cyano-4-dimethylaminopyridine tetrafluoroborate (CDAP)-activated purified capsular polysaccharides from serotype 35B having an average molecular weight between 100 kDa and 500 kDa conjugated to PsaA, wherein the glycoconjugate comprises a (w/w) percent ratio of protein to polysaccharide (protein/PS) of 0.7 to 1.2, and wherein the glycoconjugate has an average molecular weight ranging between 500 kDa to 30,000 kDa.
Overall, claim coverage is anchored on CDAP-activated purified serotype 35B capsular polysaccharides with defined conjugate/glycoconjugate average molecular weight ranges and a defined protein/PS ratio of 0.7–1.2, with conjugation specifically to PsaA in the independent claims.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
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