Tifacogin ineffective against severe community-acquired pneumonia

Tifacogin does not appear to improve outcomes of patients with severe community-acquired pneumonia (sCAP), according to a global study published online in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine, ahead of the print edition.

From 2005 to 2008, researchers enrolled 2,138 sCAP patients from 188 centers worldwide, randomizing them to receive either tifacogin, a blood-clot-inhibiting medication, or placebo intravenously for 4 days. Two doses of tifacogin (0.025 mg/kg/h and 0.075 mg/kg/h) were initially included in the study, but the higher dose was dropped early when no benefit was demonstrated. Although tifacogin did show an effect on clotting measures in the blood, researchers found that mortality rates and incidence of adverse events were similar in both the tifacogin and placebo groups.

Richard Wunderink, MD, lead author and professor of pulmonary and critical care medicine at Northwestern University’s Feinberg School of Medicine, Chicago, said the study’s findings could be the result of several factors.

“The coagulation and inflammatory responses may have been irreversibly activated before tifacogin was administered, or specific processes that occur during CAP may have blunted the effect of the drug,” he said. “However, the most logical explanation is that tissue factor activation, while important, may not be a critical step in the pathogenesis of sCAP mortality.”

Dr. Wunderink emphasized the need for additional research to improve sCAP mortality rates.