For a patient with moderate‑to‑severe atopic dermatitis refractory to high‑potency topical corticosteroids, calcineurin inhibitors, and phototherapy, what IL‑13‑targeted biologic therapies are available, what are their dosing regimens, and what safety monitoring is required?

IL-13 Targeted Biologic Therapies for Moderate-to-Severe Atopic Dermatitis

Available IL-13 Targeted Biologics

For patients with moderate-to-severe atopic dermatitis refractory to high-potency topical corticosteroids, calcineurin inhibitors, and phototherapy, tralokinumab is the only FDA-approved selective IL-13 inhibitor currently available, though dupilumab (which blocks both IL-4 and IL-13 signaling) remains the preferred first-line biologic. 1

First-Line Biologic: Dupilumab (Dual IL-4/IL-13 Blockade)

• All guideline workgroup members surveyed favored dupilumab as the first-line systemic agent for moderate-to-severe AD refractory to optimized topical therapy. 1
• Dupilumab has demonstrated an excellent safety track record in clinical trials with few major emergent safety concerns after more than 5 years in clinical practice. 1
• The American Academy of Dermatology issues a strong recommendation for the use of dupilumab in this patient population. 1

Second-Line Biologic: Tralokinumab (Selective IL-13 Inhibitor)

• Tralokinumab is the only FDA-approved selective IL-13 monoclonal antibody for moderate-to-severe AD and represents the second biologic approved for this indication. 1, 2
• The American Academy of Dermatology issues a strong recommendation for the use of tralokinumab. 1
• Tralokinumab is indicated for adults and pediatric patients ≥12 years whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. 2

Comparative Efficacy

• In network meta-analysis, tralokinumab is somewhat less effective than dupilumab at 16 weeks of treatment, with differences noted in Eczema Area and Severity Index scores. 1
• No head-to-head clinical trials have directly compared dupilumab and tralokinumab; available evidence is based on indirect comparisons from separate pivotal studies. 3
• Tralokinumab at standard dosing significantly improved signs, symptoms, and quality of life in multiple clinical trials. 1

Dosing Regimens

Tralokinumab Dosing (FDA-Approved) 2

Adults:

• Initial loading dose: 600 mg subcutaneously (either four 150 mg injections via prefilled syringe OR two 300 mg injections via autoinjector)
• Maintenance dose: 300 mg subcutaneously every 2 weeks (either two 150 mg injections via prefilled syringe OR one 300 mg injection via autoinjector)
• Alternative maintenance for responders: 300 mg every 4 weeks may be considered for adult patients <100 kg who achieve clear or almost clear skin after 16 weeks of treatment

Pediatric Patients ≥12 Years:

• Initial loading dose: 300 mg subcutaneously (two 150 mg injections via prefilled syringe)
• Maintenance dose: 150 mg subcutaneously every 2 weeks (one 150 mg injection via prefilled syringe)
• Administration should be given by or under supervision of an adult

Dupilumab Dosing (Standard Regimen) 1

Adults:

• Initial loading dose: 600 mg subcutaneously
• Maintenance dose: 300 mg subcutaneously every 2 weeks

Safety Monitoring Requirements

Pre-Treatment Considerations

• Complete all age-appropriate vaccinations as recommended by current immunization guidelines before initiating tralokinumab. 2
• Avoid use of live vaccines during treatment with IL-13 targeted biologics. 2
• Treat pre-existing helminth (parasitic) infections before initiating therapy; if patients become infected during treatment and do not respond to anti-helminth treatment, discontinue the biologic until infection resolves. 2

Contraindications

• Known hypersensitivity to tralokinumab or any excipients is an absolute contraindication. 2

Ongoing Monitoring for Adverse Events

Hypersensitivity Reactions:

• Monitor for hypersensitivity reactions, including anaphylaxis and angioedema, which have occurred after administration. 2
• Discontinue tralokinumab immediately in the event of a hypersensitivity reaction. 2

Ocular Complications:

• Instruct patients to report new onset or worsening eye symptoms to their healthcare provider immediately. 2
• Conjunctivitis and keratitis can occur with IL-13 targeted therapy. 2
• Notably, tralokinumab demonstrates lower rates of conjunctivitis (1.4%-3.8%) compared to dupilumab (8%-38% in various studies). 3, 4

Common Adverse Reactions (≥1% incidence): 2

• Upper respiratory tract infections
• Conjunctivitis
• Injection site reactions
• Eosinophilia

Key Safety Advantages of Tralokinumab

• No major safety concerns were identified in clinical trials, similar to dupilumab's favorable profile. 1
• Long-term data show comparable rates of serious adverse events between tralokinumab and dupilumab. 3
• Lower incidence of conjunctivitis and injection-site reactions compared to dupilumab represents a practical advantage for some patients. 3

Clinical Monitoring Schedule

No specific laboratory monitoring is mandated by FDA labeling, but clinicians should:

• Assess for signs of infection at each visit
• Monitor for ocular symptoms at each visit
• Evaluate treatment response using validated measures (EASI, IGA) at 16 weeks to determine continuation
• Screen for helminth infections if patient develops unexplained eosinophilia or gastrointestinal symptoms

Important Clinical Pitfalls

Premature Discontinuation:

• Patients may not achieve maximal response until 16 weeks; avoid discontinuing therapy prematurely for partial responders. 1

Inadequate Baseline Optimization:

• Before initiating any biologic, confirm that topical therapy potency was adequate and that secondary bacterial colonization has been ruled out. 5
• Continue liberal emollient use throughout biologic therapy for additive steroid-sparing benefits. 5

Conjunctivitis Management:

• If conjunctivitis develops with dupilumab, switching to tralokinumab may be beneficial given its lower conjunctivitis rates. 3, 4

Concomitant Topical Therapy:

• Biologics can be used with or without topical corticosteroids; most patients in clinical practice continue evidence-based topical therapies concomitantly. 1, 2