FDA: Glaxo Infant Vaccine Appears Safe

WASHINGTON -

Federal regulators said Friday a GlaxoSmithKline vaccine appears safe and effective for stopping the leading cause of diarrhea in infants.

However, Food and Drug Administration officials expressed concern that British drug maker's safety study of the vaccine did not follow U.S. regulations.

Glaxo has asked FDA to approve Rotarix to prevent the rotavirus in infants as young as six weeks old. A panel of FDA advisers will vote on whether to approve the drug next Wednesday.

According to the FDA, Rotarix appears to be free of life-threatening intestinal problems seen with the first rotavirus vaccine approved in the U.S. The Wyeth vaccine RotaShield was pulled from the U.S. market in 1999 after it was linked to an increase in intussusception, a twisting of the intestines.

FDA reviewers said there was no significant increase in the intestinal problems among infants taking Rotarix compared with those taking placebo. But the company adjusted the study's safety goal after recording higher-than-expected rates of intussusception in the placebo group - a change not allowed under U.S. regulations.

"Changing the primary objective while the trial is ongoing could potentially compromise the integrity of the study," the FDA said.

Glaxo was able to make the adjustment because it did the 63,000-patient study in 11 foreign countries, most in Latin America.

Agency reviewers said they were collecting more information from Glaxo to determine to weight the results, according to documents posted online Friday. The agency will seek guidance from its panelists next week, though it is not required to follow their advice.

About 55,000 U.S. children are hospitalized each year due to the rotavirus, according to the Centers for Disease Controls. The U.S. government and several medical societies already recommend infants receive vaccination for rotavirus at two, four and six months.

Rotarix is already available in more than 90 countries worldwide, according to Glaxo.

Shares of GlaxoSmithKline (nyse: GSK - news - people ) PLC rose 65 cents, or 1.5 percent, Friday to $43.97 in midday trading.