How does Ixekizumab (ixekizumab) affect white blood cell count?

Ixekizumab and White Blood Cell Count

Ixekizumab does not directly affect white blood cell count and routine WBC monitoring is not required during treatment. 1

Mechanism and Hematologic Effects

• Ixekizumab is a humanized IgG4 monoclonal antibody that selectively binds IL-17A and inhibits its interaction with the IL-17 receptor, without directly impacting bone marrow function or white blood cell production 1

• The FDA drug label for ixekizumab does not list any hematologic adverse effects, including neutropenia, leukopenia, or other white blood cell abnormalities 1

• No baseline complete blood count (CBC) is required before initiating ixekizumab, and no routine CBC monitoring is recommended during treatment 2

Clinical Monitoring Recommendations

• The American Academy of Dermatology guidelines do not include CBC monitoring in their pre-treatment or ongoing monitoring recommendations for ixekizumab 2

• Pre-treatment screening should focus on tuberculosis testing and assessment for active infections, not hematologic parameters 2, 3

• Unlike some other systemic therapies (such as methotrexate), ixekizumab does not require laboratory monitoring for bone marrow suppression 2

Important Safety Considerations

• The primary safety concern with ixekizumab is increased risk of mucocutaneous Candida infections (1.9 per 100 patient-years), not hematologic toxicity 2, 3

• Serious infections occur at low rates (0.015 per patient-year) and require treatment discontinuation until resolved, but these are not related to white blood cell suppression 2

• Patients with active infections should delay ixekizumab initiation until the infection resolves and any antibiotic course is completed 2

Contrast with Other Therapies

• This lack of hematologic monitoring distinguishes ixekizumab from conventional DMARDs like methotrexate, which require regular CBC monitoring due to bone marrow suppression risk 2

• The combination of IL-17 inhibitors with methotrexate can increase infection risk, but this is due to additive immunosuppression rather than cumulative effects on white blood cell count 2