Secukinumab: Clinical Overview
What is Secukinumab?
Secukinumab is a fully human monoclonal IgG1κ antibody that selectively neutralizes interleukin-17A (IL-17A), a key cytokine driving inflammatory pathways in psoriatic disease and spondyloarthropathies 1, 2.
FDA-Approved Indications
Secukinumab is FDA-approved for the following conditions 2:
- Moderate-to-severe plaque psoriasis (adults and pediatric patients ≥6 years)
- Psoriatic arthritis (PsA)
- Ankylosing spondylitis (AS)
- Non-radiographic axial spondyloarthritis (nr-axSpA)
- Enthesitis-related arthritis (pediatric)
- Hidradenitis suppurativa
Dosing Regimens
Plaque Psoriasis (Adults)
The recommended dose is 300 mg subcutaneously, which is more effective than 150 mg 1:
- Loading phase: 300 mg at weeks 0,1,2,3, and 4
- Maintenance: 300 mg every 4 weeks thereafter 2
Key dosing considerations:
- The 300 mg dose achieves superior PASI 90/100 responses compared to 150 mg 1
- Standard every-4-week dosing is optimal; extending to every-6-week dosing results in inferior maintenance of PASI 90 response (74.9% vs 85.7%) 3
- For patients ≥90 kg not achieving PASI 90 at week 24, consider intensifying to 300 mg every 2 weeks 3
- Do not use "as-needed" dosing after week 12—continuous every-4-week dosing is superior 1
Psoriatic Arthritis
For PsA patients with coexistent moderate-to-severe plaque psoriasis 2:
- Loading: 300 mg at weeks 0,1,2,3, and 4
- Maintenance: 300 mg every 4 weeks
For other PsA patients 2:
- With loading: 150 mg at weeks 0,1,2,3, and 4, then every 4 weeks
- Without loading: 150 mg every 4 weeks
- If inadequate response: Consider escalating to 300 mg every 4 weeks
Important context from rheumatology guidelines: For PsA with clinically relevant axial disease, IL-17A inhibition (secukinumab) is the preferred first-line biologic based on the MAXIMISE trial—the only trial specifically investigating axial PsA 4.
Ankylosing Spondylitis & Non-Radiographic Axial SpA
Subcutaneous dosing 2:
- With loading: 150 mg at weeks 0,1,2,3, and 4, then every 4 weeks
- Without loading: 150 mg every 4 weeks
- If inadequate response: Consider 300 mg every 4 weeks
Intravenous option available: 6 mg/kg at week 0, then 1.75 mg/kg every 4 weeks (max 300 mg/infusion) 2
Pediatric Dosing (≥6 years, Plaque Psoriasis)
Weight-based dosing at weeks 0,1,2,3,4, then every 4 weeks 2:
- 15-49 kg: 75 mg
- ≥50 kg: 150 mg
Hidradenitis Suppurativa
- Standard: 300 mg at weeks 0,1,2,3,4, then every 4 weeks
- If inadequate response: Escalate to 300 mg every 2 weeks 2
Monitoring Requirements
Pre-Treatment Screening
Mandatory evaluations 1:
- Tuberculosis screening: PPD or interferon-gamma release assay
- Hepatitis B testing: Screen for active or latent infection
- Baseline labs: CBC, CMP (expert consensus)
During Treatment
- No routine laboratory monitoring is required for secukinumab, unlike TNF inhibitors or JAK inhibitors
- Monitor clinically for signs of infection, particularly respiratory tract infections and candidiasis 5
- Watch for new-onset or worsening inflammatory bowel disease symptoms (abdominal pain, diarrhea, bloody stools) 2, 5
- Monitor for eczematous eruptions, which can be severe 2
Immunization Considerations
- Avoid live vaccines during treatment 2
- Complete age-appropriate vaccinations, including inactivated vaccines, prior to initiating therapy when possible
Contraindications
Absolute Contraindication
Serious hypersensitivity reaction to secukinumab or any excipient (including anaphylaxis, angioedema) 2
Relative Contraindications & Precautions
- Active infection or sepsis: Defer treatment until infection resolves; consult infectious disease if needed 1
- Untreated latent tuberculosis: Complete TB prophylaxis before initiating secukinumab 1, 2
- Chronic/recurrent infections: Exercise caution; secukinumab increases infection risk 2
- Inflammatory bowel disease (IBD): Use with caution—cases of new-onset or exacerbated IBD (Crohn's disease, ulcerative colitis) have been reported 2, 5
- History of lymphoreticular malignancy: Relative contraindication 1
Key Safety Considerations
Infections
- Most common: Nasopharyngitis, upper respiratory tract infections 2
- Candidiasis: Mild-to-moderate oral or genital candidiasis occurs more frequently than with other biologics 6, 5
- Serious infections: Rare but include tuberculosis and opportunistic infections 5
Inflammatory Bowel Disease
Critical warning: Cases of new-onset Crohn's disease and ulcerative colitis, as well as exacerbations of existing IBD, have been observed 2, 5. For PsA patients with coexistent IBD, prefer TNF inhibitors (monoclonal antibodies), IL-23 inhibitors, or JAK inhibitors over IL-17A inhibitors 4.
Neutropenia
- Reversible, transient neutropenia may occur 6
- Generally mild and self-limited
Hypersensitivity
- Anaphylaxis and angioedema reported; discontinue immediately if serious allergic reaction occurs 2
Eczematous Eruptions
- Severe eczematous eruptions have been reported 2
Immunogenicity
- Neutralizing anti-secukinumab antibodies are rare (<0.4%) and have not been associated with loss of efficacy 1
Treatment Interruption & Reinitiation
Temporarily discontinue for 1:
- Febrile illness or active infection requiring antibiotics
- Restart after complete resolution of symptoms and completion of antibiotic course
Reloading considerations 1:
- Consider repeating loading doses if:
- Patient is experiencing disease flare, AND/OR
- More than 3-4 half-lives have passed since the last dose (secukinumab half-life ~27 days)
Special Populations
Pregnancy & Lactation
Latex Allergy
- Some formulations (Sensoready pen, UnoReady pen) may contain natural rubber latex in the needle cap—avoid in patients with latex allergy 6
Clinical Pearls
For psoriasis, 300 mg is the optimal dose—do not settle for 150 mg unless cost or tolerability dictates otherwise 1
Maintain every-4-week dosing during maintenance—extending intervals compromises efficacy 3
For axial PsA, secukinumab is the preferred IL-17A inhibitor based on trial-specific evidence 4
Screen for IBD symptoms before and during treatment—this is a unique concern with IL-17A inhibitors 4, 2, 5
Candidiasis is manageable—typically mild-to-moderate and responds to standard antifungal therapy without requiring drug discontinuation 6, 5
Combination with methotrexate or other systemic therapies is not contraindicated, though no published data exist; there is no reason to consider such combinations unsafe 1
For patients with uveitis, prefer TNF inhibitor monoclonal antibodies over secukinumab 4