FDA says yes to MSD’s 21-valent adult pneumococcal jab

The rivalry between Pfizer and MSD in pneumococcal vaccines has dialled up a notch with the FDA approval of MSD’s new shot Capvaxive, the first to be aimed specifically at adults.

The 21-valent product – formerly known as V116 – covers a wider range of Streptococcus pneumoniae serotypes than any of MSD’s earlier vaccines and eight that are not covered by any other approved pneumococcal vaccine.

The approval is the strongest challenge yet to Pfizer’s pneumococcal vaccine franchise, led by its 20-valent Prevnar 20 shot, which generated $6.4 billion in sales last year from use for prevention of IPD in infants, children, and adults.

MSD’s current jab Vaxneuvance – which covers 15 serotypes – is also approved for use in infants, children, and adults and made $665 million in worldwide sales last year.

With Capvaxive, MSD (known as Merck & Co in the US and Canada) is aiming to carve out a niche in the over-50s, positioning it as the go-to vaccine used to prevent invasive pneumococcal disease (IPD) in this group.

All told, Capvaxive encompasses the serotypes responsible for around 84% of IPD cases in adults aged 50 and over, compared to around 52% with Prevnar 20, according to data from the Centers for Disease Control and Prevention (CDC). The eight serotypes unique to MSD’s vaccine account for more than a quarter (27%) of IPD cases in adults 50 and older.

The CDC’s Advisory Committee on Immunization Practices (ACIP) is scheduled to meet on Thursday 27th June to discuss and make recommendations for the use of Capvaxive in adults. All eyes are on that meeting, as the wording of the ACIP’s recommendations will give the clearest view of how competitive the new shot will be in the US market.

The CDC currently recommends pneumococcal vaccination for all adults age 65 and older and for younger adults who are immunocompromised or have certain other risk factors. If Capvaxive is recommended for the over-50s bracket, it could unlock a lucrative new category in the market, and that age-targeted approach is central to MSD’s targeted pneumococcal vaccine strategy.

It is also deploying its age-targeted serotype selection approach to V117, a paediatric vaccine that is currently in phase 3 testing.

There are around 100 different pneumococcal serotypes, causing non-invasive disease like pneumonia confined to the lungs and invasive disease where the infection can spread to the bloodstream or tissues in the central nervous system. It is estimated that more than 150,000 adults are hospitalised from pneumococcal pneumonia each year in the US.

MSD also sells an older shot called Pneumovax 23, which covers 23 serotypes, but is based on an older polysaccharide technology that does not stimulate the immune response as strongly as the newer conjugate vaccines. It brought in $412 million in 2023, down from more than $600 million in the prior year.