Respiratory · Clinical trials
Severe Asthma Clinical Trials
Approved therapies, the pivotal-trial endpoints they were judged on, the magnitude of benefit — and the drugs that failed their endpoints, and why.
Indication overview
About severe asthma — and why its trials are hard
Severe asthma refers to disease that remains uncontrolled despite high-dose inhaled corticosteroids plus a second controller, or that requires such treatment to avoid becoming uncontrolled. Although a minority of all asthma cases, it drives disproportionate exacerbations, hospitalizations, oral corticosteroid exposure and cost. Recognition that asthma is heterogeneous, with distinct inflammatory phenotypes, transformed treatment. Type 2-high disease, characterized by eosinophilia, elevated fractional exhaled nitric oxide and IgE, responds to targeted biologics. Anti-IgE (omalizumab) was the first, followed by anti-IL-5/IL-5R agents (mepolizumab, reslizumab, benralizumab) for eosinophilic disease, and anti-IL-4Ra (dupilumab) blocking IL-4/IL-13 signaling. Tezepelumab, an anti-TSLP antibody targeting an upstream epithelial alarmin, extended benefit across phenotypes including some type 2-low patients. These agents reduce exacerbations, improve lung function and quality of life, and enable oral steroid tapering. Biomarker-guided selection (blood eosinophils, FeNO, IgE) is central. The annualized asthma exacerbation rate is the pivotal efficacy endpoint across the registrational program.
Approved therapies & pivotal evidence
What's been approved — and by how much it moved the endpoint
| Drug (brand) | Approved | Setting | Pivotal trial | Primary endpoint | Magnitude of benefit |
|---|---|---|---|---|---|
| omalizumab (Xolair) | 2003 | Moderate-to-severe persistent allergic asthma with elevated IgE | INNOVATE (Phase 3) | Rate of clinically significant asthma exacerbations | ~26% reduction in clinically significant exacerbation rate vs placebo (unverified exact value) |
| mepolizumab (Nucala) | 2015 | Severe eosinophilic asthma add-on | MENSA (Phase 3) | Annualized rate of exacerbations | ~53% reduction (IV) and ~47% (SC) in annual exacerbations vs placebo |
| benralizumab (Fasenra) | 2017 | Severe eosinophilic asthma add-on | SIROCCO / CALIMA (Phase 3) | Annual asthma exacerbation rate | ~28-51% reduction in annual exacerbation rate vs placebo in eosinophilic patients |
| dupilumab (Dupixent) | 2018 | Moderate-to-severe asthma with type 2 inflammation or oral-steroid dependence | QUEST (Phase 3) | Annualized rate of severe exacerbations | ~48% reduction in severe exacerbations overall, with larger effect in high-eosinophil subgroups |
| tezepelumab (Tezspire) | 2021 | Severe asthma add-on, no phenotype/biomarker restriction | NAVIGATOR (Phase 3) | Annualized asthma exacerbation rate over 52 weeks | 56% reduction in annualized exacerbation rate vs placebo; benefit across eosinophil and FeNO levels |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in severe asthma development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| fevipiprant (DP2/CRTH2 antagonist) — LUSTER-1 and LUSTER-2 (Phase 3) | Failed to demonstrate clinically meaningful reduction in exacerbations; Novartis discontinued the program | Oral prostaglandin D2 receptor antagonism produced only modest, inconsistent effects insufficient versus established injectable biologics |
| lebrikizumab (anti-IL-13) — LAVOLTA I and LAVOLTA II (Phase 3) | Inconsistent exacerbation reduction across the two identical trials; primary benefit not reliably replicated in asthma | IL-13 blockade alone was insufficient; results varied by biomarker subgroup and the asthma program was not advanced |
Choosing the right endpoint
Primary endpoints that matter in severe asthma trials
- Annualized asthma exacerbation rate — Primary registrational endpoint for nearly all severe-asthma biologics
- Pre-bronchodilator FEV1 — Key secondary lung-function measure demonstrating physiologic benefit
- Oral corticosteroid dose reduction — Steroid-sparing endpoint (e.g., SIRIUS, ZONDA, VENTURE) in dependent patients
- ACQ-6 / AQLQ — Patient-reported asthma control and quality-of-life instruments
- Blood eosinophils / FeNO — Type 2 biomarkers used to enrich populations and predict response
How iNGENū runs severe asthma trials
Physician-led design, built for FDA submission
Endpoint & biomarker strategy
Board-certified specialists design endpoints and patient selection aligned to current FDA guidance for this indication.
FDA-ready data
Built to ICH-GCP and 21 CFR 312.120, with direct FDA submission — data accepted by the FDA, EMA and MHRA.
Faster, lower-cost delivery
~4-week ethics via the TGA CTN scheme, up to 43.5% R&D rebate, and 80–90% below US CRO cost.
Request a fixed-milestone proposal and a tailored endpoint & feasibility summary for this indication.
Frequently asked questions
Severe Asthma clinical trials — FAQs
How do I know which biologic is right for severe asthma?
Can biologics let me stop oral steroids?
Do biologics cure severe asthma?
Ready to discuss your severe asthma trial?
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