ROCKVILLE, Maryland (Reuters) -
A Johnson & Johnson
antibiotic appears safe and effective for treating a type of
pneumonia that kills tens of thousands of Americans annually,
U.S. advisers narrowly decided on Wednesday.

Several panel members voiced reservations about the
company's data, including some who voted in favor of the
intravenous drug called Doribax.

J&J is seeking Food and Drug Administration permission to
promote Doribax more widely after its launch last year for
treating complicated abdominal and urinary tract infections.

Annual sales of Doribax, known chemically as doripenem,
could reach $420 million by 2012, Credit Suisse analyst
Catherine Arnold projects.

By a 7-6 vote, the committee of advisers concluded that J&J
studies showed Doribax effectively fought hospital-acquired
pneumonia, including cases linked to use of a ventilator.

Supporters on the panel said J&J provided enough evidence
to back the drug for fighting these often deadly types of
infections, especially as older antibiotics lose their power to
resistant bacteria.

“Thinking practically as far as resistance is concerned …
you really do need to have something else,” said panelist Margo
Smith, an infectious disease expert at Washington Hospital
Center. Smith said she voted yes but was “very conflicted.”

Others said there were too many questions about J&J's study
design and how it was executed to support the wider use.

“We're not going to get perfection. However, this study
would not be the poster child for coming close,” said panel
member Thomas Fleming, a statistician at the University of
Washington in Seattle.

Panelists voted 8-5 that the drug seemed safe enough for
treating hospital-acquired pneumonia, which killed nearly
36,000 U.S. hospital patients in 2002, the FDA said. It is the
leading cause of death among healthcare-related infections.

Some of the experts noted nine deaths from pneumonia in
patients treated with Doribax in one study, compared with one
patient given an older treatment. The reason for the difference
was unclear, panelists and FDA reviewers said.

The FDA will consider the panel's advice as it decides
whether to approve wider use of Doribax. The agency usually
follows panel recommendations.

Agency reviewers, however, had already raised many of the
concerns expressed by panel members.

Questions surrounded the interpretation of chest X-rays and
whether all patients studied actually had hospital-acquired
pneumonia, FDA staff told the panel.

“There were significant issues,” said Dr. Thomas Smith,
acting clinical team leader in the FDA division that reviews
antibiotics.

J&J officials said Doribax clearly demonstrated the power
to fight a broad range of bacteria that cause pneumonia and it
was as effective as older drugs.

The drug “is a potentially important alternative agent …
especially for patients at risk for infections resistant to
other agents,” said Dr. Rebecca Redman, senior director of
clinical development for Johnson & Johnson Pharmaceutical
Research and Development.

Doribax, part of a class of antibiotics known as
carbapenems, was licensed from Japan's Shionogi & Co Ltd.

Johnson & Johnson shares gained 0.7 percent to close at
$68.19 on the New York Stock Exchange.

(Editing by Tim Dobbyn)