US FDA issues guidelines for developing drugs for acute bacterial sinusitis

The US Food and Drug Administration (FDA) has issued guidelines for the pharmaceutical  industry for developing antimicrobials for the treatment of acute bacterial sinusitis (ABS). The FDA stated that any new drug being studied for ABS should have documenting in-vitro antibacterial activity against the most commonly pathogens associated with ABS. These include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Even though animal models of ABS has been developed, particularly for S. pneumoniae infection, they cannot substitute for clinical trials in patients that must be conducted to evaluate drug safety and efficacy. The FDA recommend that two adequate and well-controlled human trials establishing safety and efficacy be conducted for that indication.  However, a single trial for an ABS indication may be appropriate if there is data from other clinical trials demonstrating effectiveness in other respiratory tract diseases such as community acquired bacterial pneumonia. Additional supportive information like pharmacokinetic and pharmacodynamic studies demonstrating concentration of the antibacterial drug in the sinuses at a level expected to be active against the common pathogens causing ABS would be required. Because direct assessment of ABS symptoms to support a conclusion of treatment benefit in response to antibacterial drug therapies is readily measured no surrogate markers of success of therapy are needed. Antimicrobials with clinically significant toxicity would not be considered appropriate for study of ABS unless treatment of a more seriously ill patient population is being considered.