Sanofi takes SK Bio-partnered pneumococcal shot into phase 3

Sanofi has moved ahead with plans to challenge Pfizer and MSD for a piece of the market for pneumococcal vaccines, taking a 21-valent shot licensed from SK Biosciences into phase 3 testing.

The pneumococcal conjugate vaccine – codenamed PCV21/GBP410 – has started pivotal trials in the prevention of both paediatric Streptococcus pneumoniae, which remains a major public health issue worldwide, with the first subject dosed last week.

At the moment, Pfizer's Prevnar franchise dominates the child and adult pneumococcal vaccine category, with sales of $4.85 billion in the first nine months of the year, slightly down on the same period of 2023. MSD (known as Merck & Co in the US and Canada), meanwhile, recorded $647 million with its rival conjugate vaccine Vaxneuvance and another $188 million from older, polysaccharide-based jab Pneumovax 23.

Pfizer's most up-to-date shot – Prevnar 20 – covers 20 S. pneumoniae serotypes, while Vaxneuvance covers 15 serotypes. However, in June, MSD got the go-ahead from the FDA for a new vaccine, called Capvaxive, which spans 21 serotypes and is being targeted specifically at the over-50s age group.

Sanofi's new challenger is billed as a "next-generation" pneumococcal conjugate vaccine that, according to the company, is the first candidate with more than 20 serotypes in the category to enter phase 3 in infants and toddlers. It will also include serotypes that are not included in currently available conjugate vaccines.

It is part of a vaccines pipeline – including antibody-based Beyfortus for respiratory syncytial virus (RSV) prevention in infants – that Sanofi expects to add €10 billion to its annual sales by 2030.

In connection with the start of the phase 3 trials of PCV21, Sanofi has expanded its alliance with South Korea-based SK Bio, first signed more than a decade ago, paying an upfront fee of €50 million along with undisclosed development and commercial milestone payments.

The revised agreement covers PCV21 and follow-up pneumococcal conjugate vaccine candidates for both paediatric and adult populations. If approved, Sanofi will commercialise the vaccines worldwide except for South Korea, where SK Bioscience will have exclusive rights.

According to Evaluate Pharma data from June, the global pneumococcal vaccine market is projected to grow from around $8.2 billion in 2024 to $9.8 billion trillion in 2028, with a compound annual growth rate (CAGR) of 4.7%. The paediatric segment represents around two-thirds of the total market.

"Given the vast unmet public health needs in invasive pneumococcal disease (IPD), we’re delighted to expand this collaboration and continue our pursuit of innovative work in PCV," remarked Sanofi's head of vaccines, Thomas Triomphe.

"Our collaboration leverages SK Bioscience’s capabilities and Sanofi’s expertise in developing and bringing innovative vaccines to people worldwide with the collective aim of reducing the global impact of pneumococcal disease."