Merck snags priority review for Prevnar 13 rival — just one month after Pfizer sent its follow-on to the FDA
Almost a decade after Prevnar 13 was approved — going on to become Pfizer’s best-selling product — Merck is one step away from having a rival vaccine to offer.
The FDA is tucking V114, the 15-valent pneumococcal conjugate vaccine, into its priority review line, meaning we’ll know by July whether Merck can finally complete the years-long journey to dethrone Prevnar 13.
Merck’s vaccine conjugates capsular polysaccharides from 15 serotypes of Streptococcus pneumonia to a carrier protein, two more than Pfizer’s.
“Invasive pneumococcal disease in adults is on the rise in many countries, driven by highly-invasive serotypes including serotype 3, which is included in the currently licensed pneumococcal conjugate vaccine, as well as serotypes not included, such as serotypes 22F and 33F,” Roy Baynes, Merck’s head of global clinical development, said in a statement.
V114 proved non-inferior to Prevnar 13 in a pivotal Phase III study involving patients over 50, with comparable safety profiles. According to Merck, it also beat Prevnar 13 on serotype 3.
The pharma giant has the only other vaccine that’s used in the US to protect against pneumococcal disease. But Pneumovax 23, a polysaccharide vaccine covering 23 serotypes, is mostly recommended for the elderly and adults with medical conditions, while Prevnar 13 is frequently administered to children younger than 2, tapping into an enormous market.
To take a snapshot at Q3 of 2020, Prevnar 13 sales topped $1.5 billion while Pneumovax earned only $375 million in the same three months.
None of this will mean a straight shot for Merck at creating a megablockbuster overnight, even if the FDA hands them an OK.
Pfizer, which has a $6 billion franchise to guard, was granted priority review weeks ago for a follow-on vaccine that covers 20 serotypes — more than any currently licensed or in late-stage development. A decision is expected by June.
Then there are the upstart biotechs with plenty of VC cash betting on a David versus Goliath tale. SutroVax and Affinivax are each bringing on platform technologies that promise to kick up deeper, more durable immune responses than traditional chemical conjugation.
For a while, though, Merck sees itself duking it out with the other behemoth.
Here’s chief marketing officer Michael Nally from a recent investor’s call:
When we look at the market, the first and foremost area that we’re looking at, is making sure that we actually confer protection across the 13 shared serotypes of PCV13. And I think what we’ve been able to demonstrate in the Phase 2 results that you’ve seen in the pediatric population is that you see a robust immune response across those 13 shared serotypes. And that’s after dose three, which I think is also an important factor, because the primary series completion is really an important time point. When you think about what’s next, then it’s about how do we add to those 13 shared serotypes.
And for our program, we’ve been able to show a robust immune response on 22F and 33F, as well as a really robust response on serotype 3, which is a key contributing factor to residual disease. And so, I think when we look at the real effort on V114, it’s always been about making sure that we provide the relevant level of protection in the core serotypes, but then add all the serotypes to it. I think the question on the first year of life will be an important one as well. And we’re looking forward to seeing more data from both our program as well as Pfizer’s program.