Berlex Laboratories, a U.S. affiliate of Schering AG, Germany, reported new data from a Phase II clinical trial showing that patients receiving Leukine (sargramostim) for the treatment of moderately to severely active Crohn's disease had significantly greater clinical response and remission rates than those receiving placebo.

"The most promising aspect of these results is they suggest Leukine may offer a unique approach to treatment for Crohn's disease that, unlike many current Crohn's disease treatments, does not involve immunosuppressive therapy," said Brian K. Dieckgraefe, co-investigator and assistant professor of medicine, Division of Gastroenterology, Washington University School of Medicine, St. Louis, Mo.

In the Phase II trial, nearly half of patients treated with Leukine (48%) had a decrease of CDAI of more than 100 points, and more than one-third of patients (40%) achieved clinical remission by the end of the study (CDAI less than or equal to 150), versus 26% and 19% of the placebo-treated patients, respectively (p=0.013 and p=0.014, respectively). More than half of patients treated with Leukine (54%) achieved a CDAI decrease of more than 70 points, versus 44% of placebo-treated patients (p=0.275). These results were achieved without the use of steroids and/or immunosuppressants.

Additionally, significant differences between Leukine and placebo were observed in the length of time to response and time to remission. Disease severity was measured using the Crohn's Disease Activity Index (CDAI), the standard measure of treatment effectiveness. A CDAI score is based on an analysis of several variables assessed by patients and physicians. A lower CDAI score correlates with less severe disease activity.

The Phase II study was initiated following positive results in an earlier Washington University pilot trial. This pilot trial was based on the hypothesis that, rather than being the result of an overactive immune system as traditionally believed, Crohn's disease may in fact result from a deficiency in innate immunity. To verify the positive pilot trial results, investigators from Washington University, as well as investigators at 34 additional trial sites across the United States, evaluated 124 patients in the Phase II trial to study the efficacy and safety of Leukine, which stimulates the immune system, in the treatment of moderately to severely active Crohn's disease.