Studies on Sanofi Antibiotic Halted

French pharmaceutical company Sanofi-Aventis said Thursday that it had suspended enrollment in studies of its antibiotic Ketek in children. The move came amid reports that the drug can cause liver failure in adults, but the company denied that the studies were halted because of safety concerns and said it was trying to ensure that the trials’ design complied with FDA requirements.

The Paris-based drug maker said the Food and Drug Administration did not request the action. It added that the suspension was not linked to a published report that an FDA official last month requested the trials be halted because Ketek could be deadly.

According to a government website, Sanofi-Aventis is conducting four studies of Ketek in 3,920 youngsters. The first started in June 2005.

The drug is approved only for adults to treat respiratory tract infections, bronchitis, sinusitis and community-acquired pneumonia.

Sanofi spokeswoman Lisa Kennedy couldn’t immediately say how many children had been enrolled or when enrollment might resume.

Ketek safety issues arose in January, after researchers reported three cases of severe liver problems, including one death. Ketek’s market share and prescriptions have plummeted since then.

In the 22 weeks ended June 2, Ketek’s share of the antibiotic market fell more than half to 0.6% while the number of prescriptions plunged 69% to 24,476. Prescriptions vary week to week, but the data provided by pharmaceutical tracking firm Verispan indicate that the drug’s use has been declining steadily.

Approved in 2004, Ketek captured only a small part of the market because physicians often shy away from new products until they establish a track record, especially when other drugs are available.