IL-5 Inhibitors & Biosimilars
3 drugsAbout IL-5
Interleukin-5 (IL-5) is a cytokine that promotes the maturation and activation of eosinophils, a type of white blood cell involved in inflammation. It plays a key role in eosinophil-driven inflammatory responses, particularly in the respiratory system.
IL-5 is a therapeutic target due to its role in eosinophil-mediated diseases. Human genetic studies provide weak support for IL-5 as a drug target, with variants linked to asthma (score 0.23). Loss-of-function variants are protective against asthma, suggesting inhibition is likely beneficial.
Three FDA-approved drugs, including NUCALA, EXDENSUR, and CINQAIR, target IL-5 for respiratory conditions. These drugs include antibodies (NUCALA, CINQAIR) and other biologics (EXDENSUR). GSK and Teva are the key players in this space.
IL-5 Genetic Evidence
Genetic evidence for IL-5 is weak, with a max score of 0.23 for asthma.
Low genetic support suggests careful patient stratification and biomarker development are needed to improve clinical trial outcomes.
💡 Why inhibition?
- • Loss-of-function variants reduce disease risk (OR < 1)
- • 100% directional consistency across 1 traits
- • Strong signal in phenotype, respiratory or thoracic disease pathways
Cross-Disease Effects
Trade-off: LowDirection of Effect
100% alignedEvidence Across Diseases
10 totalGWAS and other genetic studies link IL5 to 10 diseases.
Inhibiting this target may be therapeutic
🔗 Colocalization Evidence 20 strong
max H4: 1.00eQTL/pQTL signals for IL5 colocalize with these GWAS traits, providing causal evidence that gene expression changes drive disease risk.
Understanding these scores
Association Score (0-1): Combines all evidence types (genetic, literature, drugs, animal models). Higher = more evidence linking target to disease. This is a ranking heuristic, not a confidence score.
L2G Score: Open Targets uses a machine learning model (Locus-to-Gene) to predict which gene is causal at each GWAS locus. L2G=0.5 means ~50% probability of being the causal gene. Only associations with L2G > 0.05 are included.
Odds Ratio (OR): From gene burden studies (UK Biobank, AstraZeneca PheWAS). Measures how loss-of-function variants affect disease risk. OR<1 = protective (inhibiting target may help), OR>1 = risk (losing function causes disease).
Beta (β): Effect size for continuous traits. β<0 = protective, β>0 = risk.
Clinical Translation (~1.8x): Based on Nelson et al. 2015: drug targets with genetic evidence have ~2x higher success rates in clinical trials. We estimate: Strong support (score ≥0.7) → ~1.8x, Moderate (0.3-0.7) → ~1.3x, Weak → baseline.
Colocalization (H4): Tests whether a GWAS signal and an eQTL/pQTL signal share the same causal variant. H4 is the posterior probability that both traits are associated AND share a causal variant. H4 > 0.8 = strong evidence that gene expression/protein levels drive disease risk. This links genetic variation → gene expression → disease, supporting the target-disease connection.
Top IL-5 Drugs
GSK and Teva are the only companies with approved IL-5 targeting drugs.
The concentrated market suggests high barriers to entry, requiring differentiated products or strategies.
IL-5 Drug Modality Landscape
Modalities
Routes of Administration
IL-5 is exclusively targeted by antibodies, suggesting it may be a cell-surface or secreted protein.
Exploring alternative modalities like small molecules could offer a competitive advantage in the IL-5 space.
📈 Modality Evolution
Antibodies pioneered IL-5 targeting (2015), with other biologics entering more recently (2025).
IL-5 Clinical Trials 91 trials
Phase 1-4 trials started in 2008 or later that test an FDA-approved drug acting on IL-5. Source: ClinicalTrials.gov. How we count
Completion by Phase
| Phase | Total | Completed | Stopped | Active | Completion |
|---|---|---|---|---|---|
| Phase 1 | 6 | 5 | 1 | 0 | 83% |
| Phase 2 | 19 | 14 | 2 | 3 | 88% |
| Phase 3 | 48 | 36 | 3 | 9 | 92% |
| Phase 4 | 18 | 6 | 1 | 11 | 86% |
Top Sponsors
By Modality
Top Conditions
IL-5 Drug Approval Timeline (2015 - 2025)
The first IL-5 targeting drug was approved in 2015, with the most recent in 2025.
The recent approval indicates continued interest, but saturation may limit future opportunities.
Pro Intelligence Preview
Deep insights for drug target analysis
Competitive Landscape
- • 2 companies competing
- • Market share by company
Full Drug Portfolio
- • All 3 approved drugs
- • Approval dates & indications
Genetic Validation
- • Full genetic evidence table
- • Effect sizes & directions
Approval Timeline
- • Full 3-drug timeline
- • First-of-modality markers
Clinical Trials Analysis
- • Sponsors: 30 (6 companies)
- • Completion rates by condition
Full summary • All drugs • Genetic evidence • Trials • Timeline
How We Count Trials
- Trials: phase 1-4 interventional trials on ClinicalTrials.gov that started in 2008 or later and test an FDA-approved drug acting on IL-5. A trial counts if an approved drug acting on IL-5 is in any arm, including as a comparator, and a trial that tests two such drugs counts once. Trials that test only unapproved drugs are not counted. A trial listed as phase 1/2 counts as phase 1, and phase 2/3 as phase 2.
- Active: recruiting, not yet recruiting, enrolling by invitation, or active and no longer recruiting.
- Completion rate: of the trials that have ended, the share marked Completed rather than Terminated or Withdrawn. Completed means the trial ended as planned; it does not mean the drug worked. Suspended trials are not counted as ended.
- Stopped: terminated or withdrawn. Trials stop for many reasons, including slow enrolment and business decisions, not only safety or efficacy.
- Sponsors: the lead sponsor of each trial. Companies are the sponsors ClinicalTrials.gov classes as industry; the rest are universities, hospitals, cooperative groups, government bodies and individuals.