Pfizer's impressive Prevnar data isn't enough to win billions in adult sales

Pfizer's holding some promising data that could spell a new recommendation for its Prevnar 13 pneumococcal vaccine in older adults, adding up to $1 billion in global sales. But nabbing that recommendation will be no easy task, and after that, some of Prevnar 13's sales will ride on Pfizer's ($PFE) marketing success with the 65-and-over crowd--which has proven a tough nut to crack for competitor Merck ($MRK).

According to details from a new study, Prevnar slashed new cases of community-acquired pneumonia by 46%, Reuters reports. Vaccinated patients age 65 and older also proved 75% less likely to develop invasive infections. The results will bolster Prevnar's case for a recommendation from the CDC's Advisory Committee on Immunization Practices (ACIP)--a nod ISI Group analyst Mark Schoenebaum told FiercePharmaMarketing is "basically a requirement for reimbursement."

But as Schoenebaum said in a note to investors, it's not necessarily Prevnar's efficacy that will be up for debate when the vaccine comes up for discussion at an upcoming ACIP meeting. The key debate will be over the "herd effect"--simply put, the idea that exposure to Prevnar-vaccinated children and infants will effectively protect adults. It will be up to ACIP to decide whether it's worth giving all elderly patients Prevnar 13 when many could be protected through the herd effect. "We do not expect that a broad recommendation by the ACIP will be a layup," he wrote.

It will take more than just ACIP's blessing to get sales up to their potential. But the payoff could be huge. If Pfizer can not only win market share but also persuade many more adults aged 50-plus to get a pneumococcal vaccine, that could mean up to $5 billion in additional sales, Schoenebaum says. Market penetration would have to increase from ISI's modeled 10%-30% to 50%. Including seniors, Prevnar's sizable market encompasses 140 million eligible patients.

Competitor Pneumovax from Merck hasn't seen that kind of success--at least not yet. Sales of the vaccine, which bears ACIP's recommendation for all adults over 65, totaled $653 million last year. As Schoenebaum points out, Prevnar 13 has shown stronger antibody response data in humans and longer durability. It's also priced at about $120 per dose--roughly twice the cost of Pneumovax.

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