Pfizer Vaccine Study Could Change Medicine (And Boost Stock)

Pfizer just announced in a press release that an 85,000-patient study conducted in the Netherlands shows that its Prevnar 13 vaccine prevents pneumonia and invasive bacterial infection in adults aged 65 and older.

The news has the potential to dramatically increase the number of adults who are vaccinated against the pneumococcus bacteria. Both Prevnar 13 and an older vaccine from Merck are approved for this use by the Food and Drug Administration, but use of the vaccines has been limited because there was not proof as to how well the vaccine prevents people from becoming sick.

In fact, in the Netherlands, neither vaccine was used at all, which is what allowed Pfizer to conduct this giant study comparing Prevnar 13 to placebo. Full data will be presented at a medical meeting in India on March 12. But the results included in the press release are reason for optimism. In this study, dubbed CAPiTA, Prevnar 13 prevented community-acquired pneumonia ( CAP ) caused by the 13 strains of pneumococal bacteria in the vaccine. That was the study's main goal. On secondary goals, it prevented a first episode of non-bacteremic/non-invasive vaccine-type CAP a first episode ofnvasive pneumococcal disease. To see the design of the study, look here on the government's clinicaltrials.gov site.

In a profile of Pfizer vaccine research honcho Emilio Emini in 2011, I quoted William Schaffner, chair of preventative medicine at Vanderbilt University saying that if the trial shows Prevnar 13 can prevent pneumonia, “the interest of physicians and providers would shift very strongly toward that vaccine.”

But the full readout of the study's data next month will be crucial to determining how big its impact will be. What we still don't know: whether the vaccine improved survival for these patients, and some other key measures of efficacy. The full data read out will be importantAccording to Mark Schoenebaum, an analyst at ISI Group, Wall Street analyst on average forecast about $1 billion of additional sales for Prevnar in adults. “The actual potential could be bigger,” he wrote this morning in a short email to clients. He predicts that the stock could open up $1 today and that continued upside in this setting could drive further stock performance.