The purpose of this study is to assess the activity of multiple doses of oral rhIL-11 in patients with active Crohn's disease (Crohn's Disease Activity Index [CDAI] score from 220-400).

Inclusion Criteria:

• Documented, signed and dated informed consent to participate in this trial prior to any study related procedures being performed.
• Men and women age 16 years and over.
• Diagnosis of Crohn's disease for at least 6 months that has been appropriately documented and confirmed by radiological studies, endoscopy (with histological examination preferred), or surgical pathology (Patients with a diagnosis of Crohn's disease for less than 6 months may be included if the diagnosis is confirmed by a biopsy characteristic of Crohn's disease)

Exclusion Criteria:

Use of the following medications within the specified time period prior to randomization:

• Nonsteroidal anti-inflammatory drugs (NSAIDs; including Cyclooxygenase-2 [COX-2] inhibitors and >500 mg/day acetylsalicylic acid)
• Codeine-containing compounds
• Corticosteroid enemas