What is the recommended dose of Infliximab (Infliximab) for ulcerative colitis?

Recommended Dose of Infliximab for Ulcerative Colitis

The recommended dose of infliximab for ulcerative colitis is 5 mg/kg administered intravenously at weeks 0,2, and 6 for induction, followed by maintenance dosing every 8 weeks thereafter. 1

Dosing Regimen Details

• Induction therapy consists of infusions at weeks 0,2, and 6 at a dose of 5 mg/kg 1
• Maintenance therapy continues at 5 mg/kg every 8 weeks after the induction phase 1
• This dosing regimen has demonstrated superior efficacy compared to placebo for both induction and maintenance of remission in moderate-to-severe ulcerative colitis 1, 2

Evidence for Efficacy

• In pivotal clinical trials (ACT 1 and ACT 2), infliximab at 5 mg/kg demonstrated significantly higher clinical response rates compared to placebo:
  • 69% response rate at week 8 with 5 mg/kg vs. 37% with placebo in ACT 1 2
  • 64% response rate at week 8 with 5 mg/kg vs. 29% with placebo in ACT 2 2
• Maintenance therapy with 5 mg/kg every 8 weeks resulted in 45% clinical response at week 54 compared to 20% with placebo 2
• The risk ratio for induction of remission with infliximab is 2.85 (95% CI, 2.11-3.86) and for maintenance of remission is 2.25 (95% CI, 1.67-3.05) 1

Special Considerations

• For patients with acute severe ulcerative colitis (ASUC) who are steroid-refractory, recent evidence shows that a higher first dose of 10 mg/kg is not superior to the standard 5 mg/kg dose in achieving clinical response by day 7 3
• Combination therapy with a thiopurine (azathioprine or 6-mercaptopurine) may improve outcomes by reducing immunogenicity and increasing efficacy 1
• Therapeutic drug monitoring may be useful to guide dosing adjustments in patients with inadequate response 4
• Higher serum infliximab concentrations (≥41.1 μg/mL at week 8) are associated with greater clinical response, mucosal healing, and clinical remission rates 4

Pediatric Dosing

• The same dosing regimen (5 mg/kg at weeks 0,2, and 6, followed by maintenance dosing every 8 weeks) is recommended for children (6-17 years) with moderate-to-severe ulcerative colitis 5, 4
• Pharmacokinetics in children are generally comparable to those observed in adult populations, supporting the use of the same dosing regimen 4

Potential Dose Adjustments

• Patients who lose response during maintenance therapy may benefit from dose optimization:
  • Increasing the dose (from 5 mg/kg to 10 mg/kg) 1, 4
  • Shortening the dosing interval (from every 8 weeks to every 4-6 weeks) 4
• These adjustments should be based on clinical response and, when available, therapeutic drug monitoring 4

Administration Route

• Infliximab is traditionally administered intravenously 1
• Subcutaneous infliximab for maintenance can be used instead of intravenous infusions with similar efficacy, safety, and immunogenicity outcomes 1

Common Pitfalls and Caveats

• Patients should be screened for tuberculosis prior to initiating infliximab therapy 6
• Infliximab should not be administered to patients with active infections until the infection is adequately treated 6
• Pretreatment with diphenhydramine is recommended in patients with a history of infusion reactions 6
• Concomitant immunosuppressive therapy may reduce the risk of immunogenicity and infusion reactions 6
• The AGA recommends infliximab as a first-line biologic agent (along with vedolizumab) for biologic-naïve patients with moderate-to-severe ulcerative colitis 1