Studies involving Advanced Life Sciences Holdings Inc.'s (ADLS) pneumonia drug revealed no unexpected safety concerns, Food and Drug Administration scientists said Friday.

Chicago-based Advanced Life Sciences is seeking FDA approval for a new antibiotic to treat mild to moderate types of pneumonia. Clinical studies involving the drug, Restanza, revealed safety concerns that are common with other types of pneumonia and bacterial antibiotics, including diarrhea, nausea and headaches, FDA scientists said in briefing documents posted to the agency's Web site Friday.

An FDA-sponsored panel of medical experts will discuss Restanza Tuesday, and may recommend whether to approve the drug. If approved, Restanza would treat patients over the age of 18 who suffer from community-acquired pneumonia. Roughly 1 million people over the age of 65 suffer from the infection annually, with symptoms that include fever and hypothermia. The FDA says the infection can often result in death.

Studies of Restanza reveal a mixed picture of effectiveness when compared to current antibiotics. Several studies showed Restanza was slightly better than current antibiotics, such as clarithromycin. Other studies showed current treatments were more effective than Restanza.

Advanced Life Sciences said the medical community needs Restanza, as bacterial infections essentially mutate and render current treatments relatively ineffective. The company said Restanza's benefits outweigh its risks, "something which has become increasingly difficult for an antibacterial agent to achieve in the recent past."

Advanced Life Sciences acquired the antibiotic in 2005 from Abbott Laboratories (ABT). Abbott studied the antibiotic from 1999 to 2002 but stopped developing it. The FDA said Abbott's studies don't provide much evidence for Restanza's effectiveness, but do contribute to the product's safety profile.

-By Jared A. Favole, Dow Jones Newswires; 202.862.9207; jared.favole@dowjones.com