Efficacy of mycophenolate mofetil in patients failing 6-mercaptopurine or azathioprine therapy for Crohn's disease.

Mycophenolate mofetil (MMF) is a novel immunomodulator that may be effective in the treatment of chronic active and perianal Crohn's disease (CD). The aim of this study is to assess the efficacy of MMF in CD patients who failed or were intolerant of 6-mercaptopurine (6-MP) or azathioprine (AZA). Eleven CD patients were treated with MMF after a failed course of 6-MP/AZA, and their records reviewed retrospectively. Reasons for 6-MP/AZA intolerance or failure were recorded. Response to MMF was determined by calculation of the Harvey-Bradshaw index and ability to taper steroids. Adverse reactions to MMF were recorded. Eleven patients were identified who failed a previous trial of 6-MP/AZA and other immunomodulators and required immunomodulator therapy. Of 11 patients who started MMF, four had early adverse reactions within 8 weeks and stopped the medication. Of the remaining seven patients who took MMF for at least 8 weeks, one had a complete response, two had a partial response, and four had no response to the medication. In patients who failed 6-MP/AZA, MMF was of benefit in 3 of 11 patients with only one complete responder. This lower-than-expected response rate may indicate that patients who are resistant to 6-MP or AZA may also be resistant to MMF.

An open-label pilot study using thioguanine as a therapeutic alternative in Crohn's disease patients resistant to 6-mercaptopurine therapy.

BACKGROUND AND AIMS: A substantial number of patients with inflammatory bowel disease (IBD) fail to achieve a complete clinical response with 6-mercaptopurine (6-MP) and azathioprine (AZA). Inability to achieve therapeutic 6-thioguanine nucleotide (6-TGN) levels due to the preferential overproduction of 6-methylmercaptopurine ribonucleotides (6-MMPR) upon dose escalation characterizes a newly described subgroup of IBD patients resistant to 6-MP/AZA therapy. Treatment with 6-thioguanine (6-TG), a related thiopurine, which forms 6-TGNs more directly may be beneficial in such patients. This pilot study evaluated the safety, tolerance, and efficacy of 6-TG in the subgroup of Crohn's disease (CD) patients failing to attain adequate disease control with traditional 6-MP/AZA therapy. METHODS: Ten CD patients with preferential 6-MMPR production upon 6-MP/AZA dose escalation were enrolled in an open-label pilot study. Seven of 10 patients had experienced dose-related 6-MP toxicities. RESULTS: Seventy percent of the patients (7 of 10) responded or were in remission at week 16. Clinical response was evident by week 4 in most. 6-TGN levels were nine-fold higher with 6-TG treatment than with 6-MP, whereas 6-MMPR levels were undetectable. No patient developed a recurrence of hepatic or hematological toxicity. CONCLUSIONS: 6-TG was a safer and more efficacious thiopurine in this subgroup of IBD patients resistant to 6-MP therapy. Larger controlled trials are warranted to further evaluate both the short- and long-term safety and efficacy in this subgroup of patients as well as a broader spectrum of IBD patients.

Anti-tumor necrosis factor monoclonal antibody therapy for gastrointestinal Behçet's disease: a case report.

Behçet's disease (BD) is a multisystem immune-mediated inflammatory disorder that involves the intestine in 3%-26% of cases. Corticosteroids, 5-aminosalicylic acid derivatives, immunomodulators, and more recently thalidomide and pentoxifylline have been used to treat BD with varying degrees of success. Tumor necrosis factor (TNF)-alpha is believed to play a pivotal role in this T helper cell type 1 (Th1)-mediated disease. Infliximab, a chimeric monoclonal antibody to TNF-alpha, has been demonstrated to be an effective therapy for Crohn's disease and rheumatoid arthritis, 2 other Th1-mediated disorders. We describe a patient with chronically active, steroid-dependent BD involving the gastrointestinal tract who received 4 doses of infliximab during a 6-month period. Because most of her symptoms were gastrointestinal, the Crohn's Disease Activity Index (CDAI) was used to assess response. A rapid and dramatic improvement in both gastrointestinal and extraintestinal symptoms was observed. The CDAI score decreased from 270 points (preinfusion) to 13 points by week 2, and remission was sustained despite complete withdrawal of steroids. Colonoscopy performed 10 weeks after the first infusion showed marked endoscopic and histologic improvement. This report suggests that infliximab may be an effective new therapy for gastrointestinal BD, and perhaps other manifestations of BD as well.

An open-label pilot study of low-dose thalidomide in chronically active, steroid-dependent Crohn's disease.

BACKGROUND & AIMS: Thalidomide decreases production of tumor necrosis factor alpha, a proinflammatory cytokine associated with Crohn's disease (CD). In this study the safety, tolerance, and efficacy of low-dose thalidomide were evaluated for treatment of moderate-to-severe, steroid-dependent CD. METHODS: Twelve adult male patients with Crohn's Disease Activity Index (CDAI) scores of > or = 250 and < or = 500 despite > or = 20 mg prednisone/day were enrolled. The first 6 patients received 50 mg thalidomide every night, the next 6 received 100 mg every night. Steroid doses were stable during the first 4 weeks of treatment, then tapered during weeks 5-12. CDAI was used to assess response. RESULTS: (1) Disease activity improved consistently in all patients during weeks 1-4: 58% response, 17% remission. (2) Clinical improvement was generally maintained despite steroid taper during weeks 5-12. All patients were able to reduce steroids by >/=50%. Forty-four percent discontinued steroids entirely. In weeks 5-12, 70% of patients responded and 20% achieved remission. (3) Side effects were mild and mostly transient, with the most common being drowsiness, peripheral neuropathy, edema, and dermatitis. CONCLUSIONS: Low-dose thalidomide appears to be well tolerated and effective over a 12-week period. Results of this pilot study support the need for controlled multicenter trials of thalidomide for treatment of CD.