TRENTON, New Jersey (AP) -- Pfizer Inc. said Wednesday that its blockbuster vaccine against pneumonia, blood and other infections met its goal of preventing illness in vulnerable elderly patients in a huge study required by U.S. regulators.
The New York-based company's Prevnar 13 protects against 13 strains of pneumococcal disease, which can cause painful children's ear infections, pneumonia and life-threatening bloodstream infections.
The study, known by the acronym CAPiTA, included about 85,000 patients aged 65 or older. It found that compared to study participants getting a dummy shot, those getting the vaccine had about 46 percent fewer cases of pneumonia and about 75 percent fewer cases of invasive pneumococcal disease such as bloodstream infections.
The top-selling vaccine in history, Prevnar 13 brings Pfizer $4 billion in annual revenue. Launched at the end of 2009, it's now on sale in more than 120 countries.
In the U.S., it's approved for children from six weeks to 17 years old and for adults aged 50 and older. In 2011, the Food and Drug Administration granted accelerated approval to use the vaccine in the 65-and-up group, but required a large study to verify it actually prevented illness in them.
Senior citizens are particularly vulnerable to infections by pneumococcal bacteria, and potentially life-threatening complications, because their immune systems don't work as well as when they were younger. For the same reason, vaccines generally are only about 50 percent effective in patients 65 and older.
Pfizer noted the study is the first of any pneumococcal vaccine showing a significant reduction in pneumococcal infections in adults. That could help Prevnar 13 take more market share from rival Merck & Co.'s Pneumovax vaccine.
Pfizer's results were presented Wednesday at a medical conference on pneumococcal diseases in India.
In a report to investors, UBS analyst Marc Goodman called the results "very promising."
He wrote that he expects Prevnar 13 could generate an extra $1 billion in sales to elderly patients, but cautioned that reimbursement rates from insurers will be driven by whatever the federal Advisory Committee on Immunization Practices recommends after it reviews the Pfizer study results at a future meeting.
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