An experimental vaccine meant to protect against a broad swath of the bacteria that cause pneumonia met its main goal in a mid-stage clinical trial, according to Vaxcyte, the company developing it.
Vaxcyte said results showed its vaccine matched the performance of a standard Pfizer shot in protecting against 20 bacteria strains and exceeded it against four others among healthy adults.
Shares in the company, which began trading publicly in June 2020, surged 60% following the announcement of the data Monday morning, closing the day at $33 apiece. Following that rise, the company is worth about $2 billion, similar to the $2.1 billion price GSK paid to acquire Affinivax, a vaccine company that also has an experimental 24-strain pneumococcal shot.
Vaxcyte quickly moved to raise money at its higher value, announcing plans on Monday afternoon to hold a stock offering.
U.S. officials recommend pneumococcal vaccines for all people age 65 and older and for those 19 and older with underlying medical conditions to prevent invasive infections, which can result in hospitalizations from pneumonia, meningitis and blood infections.
Pfizer’s Prevnar franchise has been the standard option since the pharmaceutical company launched a 13-strain version in 2010. Competition heated up in 2021 when Pfizer launched a 20 strain version of Prevnar and Merck & Co. came out with a 15-strain shot called Vaxneuvance. GSK signaled it also wanted a share of the market when it bought Affinivax in May.
Vaxcyte’s data came from an early trial aiming at establishing the safety of three different doses of its shot, dubbed VAX-24, in volunteers aged 18 to 49, and then evaluating immune responses specific to the 24 pneumococcal strains in 771 volunteers aged 50 to 64. In the 20 strains covered by Prevnar 20, the immune responses stimulated by VAX-24 were “non-inferior.” Against the four other strains, Vaxcyte’s vaccine was superior, it said.
According to Vaxcyte, those four additional strains account for 10% to 15% of the pneumococcal strains causing invasive infections.
Analysts from Jefferies and Cantor Fitzgerald said the data suggest VAX-24 could be a “best-in-class” vaccine. In a note to clients, Umer Raffat, an analyst at Evercore ISI, described the results against Prevnar 20 as “even stronger than what meets the eye.”
Vaxcyte executives said they expect data from volunteers age 65 and older in the first half of 2023 and plan to begin regulatory discussions on the design of a Phase 3 trial in the second half of 2023. A Phase 3 study could produce data by 2025, they said.