Chimeric anti-tumor necrosis factor-alpha monoclonal antibody treatment of patients with rheumatoid arthritis receiving methotrexate therapy

OBJECTIVE

To evaluate the safety and efficacy of single and multiple doses of a chimeric anti-TNF-alpha monoclonal antibody (infliximab) in patients with rheumatoid arthritis (RA) who had active disease despite therapy with methotrexate (MTX).

METHODS

Twenty-eight patients with active RA despite receiving therapy with 10 mg/week of MTX were randomized to receive a single, blinded infusion of either placebo or 5, 10, or 20 mg/kg infliximab. Twenty-three patients who completed the blinded study entered an open, multiple dose extension study in which they received up to 3 additional infusions of 10 mg/kg infliximab at Weeks 12, 20, and 28. Safety, efficacy, and pharmacokinetics were evaluated during the blinded and open trial.

RESULTS

There were no serious infusion related reactions. In the blinded phase, 17 (81.0%) of 21 patients receiving infliximab achieved an American College of Rheumatology (ACR) 20% response at some point during the 12 weeks of followup compared to one (14.3%) of 7 patients receiving placebo (p = 0.003). Clinical improvement was evident by the first week and was sustained through Week 12. For the 19 patients who received infliximab during the blinded part of the trial and continued into the open label trial, 53% maintained an ACR 20% response with multiple infusions of 10 mg/kg infliximab through Week 40. Three patients withdrew from the trial during the open continuation phase because of adverse events: cellulitis, infusion related dizziness and headache, and vasculitic rash. Infliximab in doses of 5 to 20 mg/kg had a mean terminal half-life ranging from 9 to 12 days and was detectable in sera from most patients 8 to 12 weeks after dosing.

CONCLUSION

Infliximab is generally well tolerated during 40 weeks of therapy. A single infusion of 5 to 20 mg/kg infliximab significantly decreases the signs and symptoms of RA compared to placebo in patients with active disease receiving MTX. Multiple doses of infliximab produce sustained clinical benefit for up to 40 weeks.

Efficacy and safety of retreatment with anti-tumor necrosis factor antibody (infliximab) to maintain remission in Crohn's disease

BACKGROUND & AIMS

Infliximab, an anti-tumor necrosis factor monoclonal antibody, rapidly reduces signs and symptoms of active Crohn's disease. The aim of this study was to determine whether repeated infusions of infliximab would effectively and safely maintain the remitting benefit.

METHODS

The efficacy, safety, pharmacokinetics, and immunogenicity of 4 repeated treatments with 10 mg/kg infliximab given every 8 weeks were compared with the effects of placebo in a randomized, double-blind, placebo-controlled, parallel group trial. Seventy-three patients with active Crohn's disease who had not adequately responded to conventional therapies and then had demonstrated a clinical response (>/=70-point decrease in the Crohn's Disease Activity Index) to an initial infusion of infliximab (or placebo) were studied.

RESULTS

Retreatment with infliximab maintained the clinical benefit through the retreatment period and 8 weeks after the last infusion in nearly all patients retreated with infliximab. Median values for Crohn's Disease Activity Index, inflammatory bowel disease questionnaire (a quality of life measurement), and serum C-reactive protein concentration were maintained at remission levels with infliximab retreatment, but not with placebo retreatment. Retreatment with infliximab every 8 weeks maintained serum infliximab concentration and was well tolerated with a low incidence of immunogenicity. One case of lymphoma and 1 case of suspected lupus were reported; the complete long-term safety profile of infliximab requires additional clinical investigation.

CONCLUSIONS

Long-term treatment with infliximab showed efficacy and tolerability in managing symptoms of patients with active Crohn's disease not responding to conventional treatments.

Infliximab for the treatment of fistulas in patients with Crohn's disease

BACKGROUND

Enterocutaneous fistulas are a serious complication of Crohn's disease and are difficult to treat. Infliximab, a chimeric monoclonal antibody to tumor necrosis factor alpha, has recently been developed as a treatment for Crohn's disease. We conducted a randomized, multicenter, double-blind, placebo-controlled trial of infliximab for the treatment of fistulas in patients with Crohn's disease.

METHODS

The study included 94 adult patients who had draining abdominal or perianal fistulas of at least three months' duration as a complication of Crohn's disease. Patients were randomly assigned to receive one of three treatments: placebo (31 patients), 5 mg of infliximab per kilogram of body weight (31 patients), or 10 mg of infliximab per kilogram (32 patients); all three were to be administered intravenously at weeks 0, 2, and 6. The primary end point was a reduction of 50 percent or more from base line in the number of draining fistulas observed at two or more consecutive study visits. A secondary end point was the closure of all fistulas.

RESULTS

Sixty-eight percent of the patients who received 5 mg of infliximab per kilogram and 56 percent of those who received 10 mg per kilogram achieved the primary end point, as compared with 26 percent of the patients in the placebo group (P=0.002 and P=0.02, respectively). In addition, 55 percent of the patients assigned to receive 5 mg of infliximab per kilogram and 38 percent of those assigned to 10 mg per kilogram had closure of all fistulas, as compared with 13 percent of the patients assigned to placebo (P=0.001 and P=0.04, respectively). The median length of time during which the fistulas remained closed was three months. More than 60 percent of patients in all the groups had adverse events. For patients treated with infliximab, the most common were headache, abscess, upper respiratory tract infection, and fatigue.

CONCLUSIONS

Infliximab is an efficacious treatment for fistulas in patients with Crohn's disease.

Endoscopic and histological healing with infliximab anti-tumor necrosis factor antibodies in Crohn's disease: A European multicenter trial

BACKGROUND & AIMS

Tumor necrosis factor (TNF) is a pivotal cytokine in intestinal inflammation. Controlled trials using a chimeric anti-TNF antibody (infliximab) have shown its efficacy in refractory Crohn's disease.

METHODS

Endoscopic and histological response to infliximab was investigated in a multicenter, randomized, double-blind, and placebo-controlled trial including 30 patients with active Crohn's disease undergoing ileocolonoscopy before and 4 weeks after intravenous administration of 5, 10, or 20 mg/kg of infliximab or placebo as a single infusion. Lesions were scored by means of the validated Crohn's Disease Endoscopic Index of Severity (CDEIS). Endoscopic biopsy specimens were taken during both procedures from 9 of 30 patients and scored by a single gastrointestinal pathologist.

RESULTS

CDEIS scores decreased significantly in most infliximab-treated patients without an apparent dose response. No endoscopic improvement was observed in the placebo group. The changes in CDEIS correlated highly with those of the Crohn's Disease Activity Index. At a histological level, disappearance of the inflammatory infiltrate was observed in infliximab-treated patients but not in placebo-treated ones; however, architectural changes persisted in most patients. Strictures developed in several patients.

CONCLUSIONS

Clinical improvement after infliximab therapy in active Crohn's disease is accompanied by significant healing of endoscopic lesions and disappearance of the mucosal inflammatory infiltrate.

A short-term study of chimeric monoclonal antibody cA2 to tumor necrosis factor alpha for Crohn's disease. Crohn's Disease cA2 Study Group

BACKGROUND

Studies in animals and an open-label trial have suggested a role for antibodies to tumor necrosis factor alpha, specifically chimeric monoclonal antibody cA2, in the treatment of Crohn's disease.

METHODS

We conducted a 12-week multicenter, double-blind, placebo-controlled trial of cA2 in 108 patients with moderate-to-severe Crohn's disease that was resistant to treatment. All had scores on the Crohn's Disease Activity Index between 220 and 400 (scores can range from 0 to about 600, with higher scores indicating more severe illness). Patients were randomly assigned to receive a single two-hour intravenous infusion of either placebo or cA2 in a dose of 5 mg per kilogram of body weight, 10 mg per kilogram, or 20 mg per kilogram. Clinical response, the primary end point, was defined as a reduction of 70 or more points in the score on the Crohn's Disease Activity Index at four weeks that was not accompanied by a change in any concomitant medications.

RESULTS

At four weeks, 81 percent of the patients given 5 mg of cA2 per kilogram (22 of 27 patients), 50 percent of those given 10 mg of cA2 per kilogram (14 of 28), and 64 percent of those given 20 mg of cA2 per kilogram (18 of 28) had had a clinical response, as compared with 17 percent of patients in the placebo group (4 of 24) (p<0.001 for the comparison of the cA2 group as a whole with placebo). Thirty-three percent of the patients given cA2 went into remission (defined as a score below 150 on the Crohn's Disease Activity Index), as compared with 4 percent of the patients given placebo (P=0.005). At 12 weeks, 41 percent of the cA2-treated patients (34 of 83) had had a clinical response, as compared with 12 percent of the patients in the placebo group (3 of 25) (P=0.008). The rates of adverse effects were similar in the groups.

CONCLUSIONS

A single infusion of cA2 was an effective short-term treatment in many patients with moderate-to-severe, treatment-resistant Crohn's disease.