Pneumococcal polysaccharide serotype 9V conjugated to CRM197

Table of contents

• What is pneumococcal polysaccharide serotype 9V conjugated to CRM197?
• How does it work?
• Which conditions is it used or studied for?
• How is it given?
• What do the clinical trials show?
• What side effects are known?

What is pneumococcal polysaccharide serotype 9V conjugated to CRM197?

Pneumococcal polysaccharide serotype 9V conjugated to CRM197 is one active component of pneumococcal conjugate vaccines. The full substance name in the registry is PNEUMOCOCCAL POLYSACCHARIDE SEROTYPE 9V CONJUGATED TO CRM197. It appears as a component of authorised vaccines including Vaxneuvance (a 15-valent pneumococcal conjugate vaccine) and Apexxnar (a 20-valent vaccine, also known as Prevnar 20).^[5][4] The substance is classified under the therapeutic area of bacterial infections and mycoses, and it has marketing authorisation in the EU as part of Vaxneuvance.^[1] In the trial data it appears both as the studied substance (Test role) and as a comparator.^[1]

How does it work?

CRM197 is a non-toxic mutant of diphtheria toxin, produced recombinantly in Pseudomonas fluorescens. The polysaccharide from pneumococcal serotype 9V is conjugated (chemically linked) to this carrier protein.^[5] This conjugation helps the immune system recognise the pneumococcal polysaccharide and produce antibodies against serotype 9V. The vaccine is adsorbed on aluminium phosphate, which acts as an adjuvant to enhance the immune response.^[5]

Which conditions is it used or studied for?

• Pneumococcal disease — infections caused by Streptococcus pneumoniae, including invasive pneumococcal disease (IPD), pneumonia and meningitis. The vaccine components target specific serotypes such as 9V.
• Pneumococcal immunisation — the registered trial studies the vaccine in healthy infants from approximately 2 months of age to assess the immune response.^[1]
• Invasive pneumococcal disease in older adults — a Phase 4 observational study listed in supplementary sources is evaluating vaccine effectiveness of a 20-valent vaccine in adults aged 65 years and above.^[2]

How is it given?

The substance is given as a suspension for injection by intramuscular injection.^[1] Vaxneuvance is supplied in a 0.5 mL pre-filled glass syringe, with or without needles depending on the pack.^[5] One dose of Vaxneuvance contains 2.0 micrograms of pneumococcal polysaccharide serotype 9V conjugated to CRM197 and adsorbed on aluminium phosphate.^[5] A paediatric formulation is available in two product records.^[1]

What do the clinical trials show?

The registry data contains one Phase 3 trial (EU CT number 2023-507600-32-00) with 1,113 enrolled healthy infants from approximately 2 months of age. The trial is currently authorised.^[1] It compares a 21-valent pneumococcal conjugate vaccine (PCV21) against the 15-valent Vaxneuvance (15vPCV). The primary outcomes are the seroresponse rate and IgG concentration for PCV21 and 15vPCV serotypes, measured 30 days after the toddler dose. The study aims to show non-inferiority of PCV21 versus 15vPCV for the 15 shared serotypes, and superiority for the 6 serotypes unique to PCV21.^[1] The substance itself appears in the trial both as the tested vaccine component and as part of the comparator Vaxneuvance.^[1]

What side effects are known?

The provided supplementary sources do not contain specific side effect information for this substance. The patient group direction source refers to a different vaccine (PPV23) and does not list side effects for the conjugate vaccines.^[3]