Biologicals in Severe Pediatric Asthma (Omalizumab, Dupilumab)

Introduction and Clinical Burden

Target Type 2 inflammation in severe pediatric asthma refractory to optimized Step 4-5 therapy (high-dose ICS-LABA) or oral corticosteroid (OCS) dependence.
Approved for pediatric patients $\geq$ 6 years of age.
Mitigate poor disease control, which otherwise causes school absenteeism, irreversible airway remodeling, and growth impairment.

Mechanism: Binds free IgE, directly reducing mast cell activation.
Phenotype: Indicated for allergic asthma demonstrating perennial aeroallergen sensitization.
Biomarker Requirement: Total serum IgE levels between 30-1500 IU/mL.
Dosing: Administered via subcutaneous injection every 2-4 weeks, calculated based on body weight and baseline IgE levels.
Durability: Benefits may persist up to 1 year post-discontinuation in carefully selected cases.

Mechanism: Blocks IL-4 and IL-13 signaling pathways, addressing broader inflammatory cascades.
Phenotype: Eosinophilic, allergic, or OCS-dependent Type 2 inflammation.
Biomarker Requirement: Blood eosinophil count (BEC) $\geq$ 150-300/ $μ$ L or Fractional Exhaled Nitric Oxide (FeNO) $\geq$ 20-25 ppb.
Dosing: Subcutaneous injection 200/300 mg every 2 weeks.

Efficacy: Biologics collectively reduce severe exacerbations by 50-65%, enhance FEV1, and minimize OCS exposure.
VOYAGE Trial (Dupilumab): Achieved 59-65% exacerbation reduction and improved ACQ-7 scores in children aged 6-11 years, with 77-79% remaining exacerbation-free at 52 weeks.
Comparative Data: Dupilumab demonstrates superiority over omalizumab in patients with frequent exacerbations, FEV1 <70% predicted, or comorbid nasal polyps.
Timing: Early biologic initiation ( $\leq$ 11 years) correlates with 53% lower exacerbation odds, amplifying benefits in polysensitized children.
Safety: Mild adverse events include injection-site reactions, eosinophilia, and viral upper respiratory infections. Serious adverse events remain <2%.

Positioned definitively as Step 5 add-on therapy.
Decision Tree: Dupilumab preferred for eosinophilic/OCS-dependent phenotypes; Omalizumab preferred for strictly IgE-mediated allergy.
Emphasizes biomarker reassessment (BEC/FeNO $\geq$ 3 times) if baseline values are borderline.

CHEST 2026 favors dupilumab for patients with $\geq$ 2 exacerbations annually, prior hospitalizations, or steroid dependence.
IAP 2025-2026 strongly endorses GINA-aligned, phenotype-driven selection following early referral to a pediatric pulmonologist or allergist.

Economic Barriers: High procurement costs (₹20,000-50,000 per dose) restrict widespread access.
Logistics: Cold-chain maintenance, limited specialist availability, and injection anxiety hinder compliance.
Government Initiatives: MoHFW and ICMR Standard Treatment Workflows (STWs) acknowledge biologics for refractory cases, facilitating limited access via CGHS, Railways, and select Ayushman Bharat packages.
Future Directions: Integration of biosimilars (e.g., omalizumab-igec) is urgently needed to drive cost-reduction and achieve treatment equity.