The purpose of this study is to assess the tolerability, pharmacokinetics and safety of 2 and 6 micro g/kg/day sargramostim administered subcutaneously once daily for 4 weeks, and to assess the efficacy and safety of 6 micro g/kg/day sargramostim administered subcutaneously once daily for 8 weeks in comparison with placebo, in patients with moderately to severely active Crohn's disease.

On 29 May 2009, Bayer began transitioning the sponsorship of this trial to Genzyme. NOTE: This study was originally posted by sponsor Berlex, Inc. Berlex, Inc. was renamed to Bayer HealthCare, Inc.

Inclusion Criteria:

• Confirmed diagnosis of Crohn's disease (endoscopic or radiological evaluation) at least 4 months prior to receiving the first dose of study drug
• Moderately to severely active Crohn's disease at time of screening (i.e., Crohn's disease activity index [CDAI] >220 and <475 points)

Exclusion Criteria:

• Colostomy or ileostomy
• Immediate need for gastrointestinal (GI) surgery for active GI bleeding, peritonitis, intestinal obstruction, or intra-abdominal or perianal abscess requiring surgical drainage
• GI surgery within 6 months prior to receiving the 1st dose of study drug
• Symptoms of bowel obstruction or confirmed evidence of a clinically-significant stricture within the last 6 months that has not been surgically corrected