What is the typical duration of infliximab (chimeric monoclonal antibody against tumor necrosis factor-alpha) treatment for patients with Crohn's disease?

Infliximab Duration for Crohn's Disease

Infliximab should be continued indefinitely as long-term maintenance therapy in patients with Crohn's disease who achieve remission, as routine discontinuation after 1 year of stable remission is associated with approximately 33% relapse risk within 1-2 years. 1, 2

Maintenance Therapy Recommendation

Continue infliximab maintenance therapy without planned discontinuation in patients who have achieved remission. The most recent ECCO guidelines (2024) provide a strong recommendation with moderate-quality evidence that infliximab should be used as maintenance therapy in moderate-to-severe Crohn's disease. 1 The British Society of Gastroenterology explicitly states that routine withdrawal after 1 year of stable remission is not recommended due to elevated relapse risk. 2

Standard Dosing Schedule

• Induction regimen: 5 mg/kg IV at weeks 0,2, and 6 1, 3
• Maintenance regimen: 5 mg/kg IV every 8 weeks thereafter 1, 4
• The landmark ACCENT I trial established this dosing schedule, demonstrating that patients receiving scheduled maintenance infliximab every 8 weeks had significantly higher remission rates at week 30 (39-45%) compared to episodic dosing (21%). 4

Combination Therapy Duration

Combine infliximab with thiopurines for the first 6-12 months of maintenance therapy, then consider de-escalation to infliximab monotherapy. 1

• Combination therapy during induction and the first 6-12 months improves efficacy and reduces immunogenicity. 1
• Once long-term remission is established, the immunomodulator can be withdrawn in most patients, though caution is warranted in patients with prior immunogenicity to anti-TNF agents. 1
• Concurrent immunomodulators significantly enhance the proportion of patients maintaining response over time. 5

Long-Term Outcomes and Monitoring

The annual risk of loss of response to infliximab is approximately 12% per patient-year of treatment. 5 However, discontinuation carries substantial risks:

• Approximately one in three patients (33%) will relapse within 1-2 years after discontinuation, even with corticosteroid-free clinical, biochemical, and endoscopic remission. 2
• Among patients who discontinued infliximab while having response but not complete remission, 50% experienced disease flare within five months (median 22 weeks). 6
• Loss of response upon re-treatment may occur, and antibody formation can develop if infliximab is discontinued and restarted. 2

Assessment Timing

Evaluate symptomatic response between 8-12 weeks after induction to determine need for therapy modification. 1

• Significant improvements in symptomatic response can be seen as early as 1-2 weeks, with remission rates reaching maximum at week 8 and plateauing thereafter. 1
• Patients who fail to respond by 12-14 weeks are unlikely to benefit from continued therapy. 1
• Once response occurs, subsequent endoscopic assessment should confirm complete remission, though optimal timing remains uncertain. 1

Management of Loss of Response

For patients losing response, consider dose intensification before switching therapies. 5, 7

• After loss of response, 56% of patients achieve remission and 40% achieve partial response with the first intensified dose. 5
• Treatment intensification based on endoscopic findings of exacerbation results in significantly lower discontinuation rates (7.1%) compared to intensification based on clinical symptoms alone (43.8%). 7
• Therapeutic drug monitoring can guide optimization, though current evidence provides insufficient support for routine proactive TDM over standard care. 1

Critical Pitfalls to Avoid

• Never discontinue infliximab based solely on achieving remission at 1 year. This contradicts high-quality guideline evidence showing increased relapse risk. 1, 2
• Do not switch between anti-TNF therapies in patients doing well on current therapy. 1, 2
• Avoid stopping immunomodulators too early. Maintain combination therapy for at least 6-12 months before considering de-escalation. 1
• Do not ignore smoking status. Smoking significantly decreases maintenance of response and should be addressed aggressively. 5