Infliximab for Severe Plaque Psoriasis: Patient Selection Criteria
Infliximab is most appropriate for patients with very severe plaque psoriasis, defined as PASI ≥ 20 and DLQI ≥ 18, who have failed or cannot use ciclosporin, methotrexate, or PUVA therapy. 1
Primary Indications for Infliximab
Disease Severity Criteria
- Patients with very severe plaque psoriasis (PASI ≥ 20, DLQI ≥ 18) according to licensing criteria 1
- Patients with severe psoriasis (PASI ≥ 10, DLQI > 10) who meet additional qualifying criteria 1
- Patients with disease affecting high-impact sites with significant functional or psychological morbidity (such as acral psoriasis) may be considered even if they fall outside standard severity definitions 1
Treatment History Requirements
Patients must fulfill at least one of the following:
- Previous systemic therapies (ciclosporin, methotrexate, PUVA) have failed 1, 2
- Standard systemic therapies are contraindicated 1
- Patient is intolerant to standard systemic therapies 1
- Patient is at risk of developing clinically important treatment-related toxicity with standard therapies 1
Special Clinical Scenarios
Psoriatic Arthritis
- Infliximab is strongly recommended for patients with plaque psoriasis of any severity when associated with significant psoriatic arthritis 1
- Particularly beneficial for patients with three or more tender joints and three or more swollen joints 1
- Demonstrated ability to inhibit radiographically detected joint damage in psoriatic arthritis patients 2
Special Anatomical Locations
- Recommended as monotherapy for moderate-to-severe plaque psoriasis affecting: 1
Other Psoriasis Subtypes
- May be considered for patients with other subtypes of psoriasis: 1
Treatment Protocol and Response Assessment
Dosing Regimen
- Standard dosing: 5 mg/kg intravenously at weeks 0,2, and 6, followed by maintenance every 8 weeks 1, 2
- For patients with inadequate response, more frequent dosing (as often as every 4 weeks) or higher dosing (up to 10 mg/kg) may be considered 1
Response Assessment
- Evaluate treatment response at 10-14 weeks 1
- Continue treatment only in responders (typically defined as achieving at least PASI 75) 2, 3
- Rapid response is typically observed, with significant improvement often seen as early as 2 weeks 3
Combination Therapy Considerations
Infliximab may be combined with:
- Topical therapies (high-potency corticosteroids with/without vitamin D analogues) to augment efficacy 1
- Methotrexate to possibly enhance efficacy and reduce development of antibodies to infliximab 1
- Acitretin in selected cases 1
Important Caveats and Precautions
Safety Considerations
- Perform pre-treatment screening for tuberculosis (chest X-ray, tuberculin test) 4
- Monitor for infusion reactions, which may necessitate treatment discontinuation 5, 4
- Be vigilant for development of antinuclear antibodies, which may occur in approximately 21% of patients 4
- Weight gain may occur in a significant proportion of patients (57.8% in one study) 4
- Consider the risk of serious infections and malignancies, including lymphomas 5
Treatment Durability
- Interrupted therapy should be avoided due to increased risk of infusion reactions and poorer disease control 1
- Some patients may experience loss of response over time, potentially requiring dose adjustments 6
- Approximately 87% of patients may require higher than standard dosing to maintain clearance in long-term treatment 6
By following these criteria and considerations, infliximab can be an effective treatment option for appropriately selected patients with severe plaque psoriasis, offering rapid and significant improvement in disease symptoms and quality of life.