FDA staff questions J&J antibiotic studies

WASHINGTON (Reuters) - U.S. drug reviewers have "several major concerns" about effectiveness data supplied by Johnson & Johnson in a bid to win approval for expanded use of its Doribax antibiotic, according to documents released on Monday.

The Food and Drug Administration will ask an advisory panel that meets on Wednesday if the company has demonstrated that Doribax is safe and effective for hospital-acquired pneumonia and pneumonia associated with placement of a ventilator.

The injectable drug, known generically as doripenem, was approved in October 2007 for treating complicated urinary tract and abdominal infections.

Concerns include questions about the interpretation of chest X-rays in the pneumonia studies, a summary from the FDA staff said.

The agency's review of company data from two studies "revealed several major concerns that limit the ability to evaluate the efficacy of doripenem," the summary said.

The FDA plans to ask the advisory panel if Johnson & Johnsons's study design is acceptable. The company aimed to show Doribax worked as well as other antibiotics. Some industry critics have questioned if that type of "non-inferiority" study is appropriate for judging antibiotics.

Johnson & Johnson, in a separate summary, said Doribax was effective against a broad range of bacteria and its side effects were similar to other widely used therapies.

(Reporting by Lisa Richwine; editing by Gerald E. McCormick and Dave Zimmerman)