Critical Therapeutics Initiates Open-Label Study of ZYFLO

Critical Therapeutics has initiated an open-label, Phase IIIb study of its investigational drug, ZYFLO Filmtab, for patients with asthma who have previously benefited from ZYFLO and require it to control their asthma.

In addition, the FDA has approved the enrollment in the study of patients with mastocytosis, an orphan disease involving new or abnormal cell growth, where ZYFLO (zileuton tablets) is deemed essential for the treatment of symptoms. ZYFLO is the only 5-lipoxygenase inhibitor approved in the U.S. for the treatment of asthma in adults and children 12 years of age and older. Critical Therapeutics licensed exclusive worldwide rights to ZYFLO and other forms of zileuton from Abbott Laboratories and is in the process of transferring the manufacturing to new sites.

The company expects to submit a supplemental new drug application to the FDA for the change in manufacturing process and sites and, subject to FDA approval of these new manufacturing sites, expects ZYFLO to be commercially available in the fourth quarter of 2005. ZYFLO has been commercially unavailable since early 2004, when Abbott Laboratories' remaining supply was depleted.