While Pfizer and Merck & Co. have garnered considerable hype around their updated pneumococcal vaccines, Vaxcyte is pointing to new data as evidence it shouldn’t be discounted.
The California biotech found that VAX-24 showed non-inferiority against 90% of the serotypes covered by Pfizer’s Prevnar 20 in a phase 2 trial of adults aged 65 and older and was superior against the four serotypes unique to Vaxcyte’s candidate, according to an announcement Monday. VAX-24 was found to have higher geometric mean ratio responses—a measure of the immune system’s response to bacteria—in 16 out of 20 serotypes covered by Prevnar 20.
The results came with encouraging six-month safety data of the 65 and older cohort as well as 18-64-year-old patients in a phase 1/2 study. Vaxcyte said its vaccine has a similar tolerability profile to Prevnar 20 across all age groups, with most local and system reactions classed as mild to moderate. One treated patient in the 65 and older group with multiple pre-existing conditions died of a sudden cardiac arrest six months after vaccination but the principal investigator deemed the death unrelated to the shot.
The company is looking to prise open Pfizer’s steel grip on the pneumococcal market that’s only tightened in the last year. The Big Pharma reported a 20% increase in revenue for the Prevnar family—which includes Prevnar 13 and Prevnar 20—in 2022 compared to the previous year. In total, the range raked in more than $6.3 billion in revenue.
Vaxcyte will also have to contend with Merck, which currently leads the regulatory race for the key infant population. The Gardasil maker won an FDA nod in June 2022 for its shot, Vaxneuvance, to vaccinate children from 6 weeks old through to 17 years. Pfizer received priority review of Prevnar for the same age group in January.
Vaxcyte is still a couple of years away from a possible market entry for VAX-24, however. In light of this data, the company says it will speak to regulators about its phase 3 plans with a potential readout expected in 2025. It’s a similar timeline for the company’s infant option, with safety, tolerability and immunogenicity data set for 2025. Vaxcyte is planning to ask regulators to greenlight a study of a 31-valent pneumococcal conjugate vaccine, VAX-31, in the second half of this year.