With trial results in infants, Merck advances next-gen pneumococcal shot Vaxneuvance in race against Pfizer

Vaccine
Prevnar 13 dominates the pneumococcal vaccine market but Merck's next-gen shot, Vaxneuvance, has a chance to make noise, especially if it can win approval in children. (Getty / E+ / Geber86)

In the race to win FDA approvals for their next-gen pneumococcal vaccines in adults, Pfizer edged Merck by a month—a relative photo finish in the pharma industry.

But Merck has sprinted ahead in testing its shot in a more critical demographic—children. On Wednesday, Merck revealed late-stage trail data that puts Vaxneuvance a step closer to a more sweeping endorsement.

In a phase 3 study in infants enrolled between 42 and 90 days old, Merck’s 15-valent shot met its objectives by performing comparably to Pfizer’s Prevnar 13 in efficacy and safety measures.

Merck plans to submit its application for FDA approval in kids by the end of this year. Still to come are data on older children. Pfizer’s next-gen vaccine, Prevnar 20, trails in testing on kids by roughly a year.

“By nature, pneumococcal disease is constantly evolving," Roy Baynes, Merck’s chief medical officer, said in a statement. "Strains of the disease associated with invasiveness cause significant disease burden in children, calling for innovation to help protect this vulnerable population."

Children make up about 80% of the pneumococcal vaccine market, so there's a lot at stake in the race to vaccinate that population. Pfizer's Prevnar 13, currently the top shot on the market, generated $5.95 billion last year in both children and adults.

Merck's 15-valent Vaxneuvance won FDA approval in July, trailing Pfizer's next-gen, 20-valent shot Prevnar 20 by one month. 

RELATED: Merck’s next-gen pneumococcal shot scores FDA nod, setting up high-stakes clash with rival Pfizer

In the recent study results, investigators gave 1,720 infants a four-dose regimen of Vaxneuvance or Prevnar 13 at 2, 4, 6 and 12-15 months of age. The two vaccines had the same general safety profile. At 30 days beyond the third and fourth doses, Vaxneuvance’s protection matched Prevnar 13 in all 13 shared serotypes based on serotype-specific response rates, Merck said.

As a secondary objective, Vaxneuvance showed superior immune responses to Prevnar 13 for the shared serotype 3 and for its two unique serotypes, 22F and 33F. These three serotypes represent more than a quarter of all cases of invasive pneumococcal disease in children younger than 5, Merck said.

RELATED: On a vaccine roll, Pfizer scores FDA nod for Prevnar 13 follow-up ahead of rival Merck

As Merck preps a filing for children by the end of the year, market watchers expect Pfizer to follow by the end of 2022.

Meanwhile, Pfizer is also seeking an edge by testing Prevnar 20 alongside its COVID-19 vaccine in adults 65 and older. 

As for Merck, a few weeks ago, the company lost its pediatric leader in the development of Vaxneuvance as Kara Bickham departed to take the chief medical officer role at Affinivax. There she will lead that company’s efforts to bring a 24-valent pneumococcal vaccine to the market that could one day challenge Vaxneuvance and Prevnar’s next-gen entry.