JAK1 Inhibitors
12 drugsAbout JAK1
Janus Kinase 1 (JAK1) is a non-receptor tyrosine kinase that mediates intracellular signaling pathways downstream of cytokine and growth factor receptors, influencing immune cell function and inflammatory responses.
JAK1 is a key immunology target supported by strong genetic evidence linking its variations to diseases like hypothyroidism (score 0.82) and autoinflammation (score 0.80). Strong eQTL/pQTL signals further support JAK1 as a therapeutic target.
JAK1 is targeted by 12 FDA-approved small molecule drugs including XELJANZ, RINVOQ and JAKAFI, indicated for immunology and other conditions. Multiple companies have approved JAK1 drugs, including PF PRISM CV, AbbVie, and INCYTE CORP.
Strategic Insights
ℹ️ How we calculate- Validated target with strong trial activity and 81% attractiveness score.
- White space opportunity in Essential Thrombocythemia with only 5 trials.
Human Genetic Evidence Strong
JAK1 has strong genetic support with a max score of 0.82 linking it to 12 diseases.
Strong genetic support suggests that clinical trials targeting genetically validated indications have a higher probability of success.
Evidence Across Diseases
12 totalGWAS and other genetic studies link JAK1 to 12 diseases.
🔗 Colocalization Evidence 20 strong
max H4: 1.00eQTL/pQTL signals for JAK1 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 Drugs
Nine companies have approved JAK1 drugs, with PF PRISM CV, AbbVie, and INCYTE CORP leading the market.
The presence of multiple players indicates a competitive market, requiring differentiated strategies for new entrants.
| Drug | Company | Approved | Indications |
|---|---|---|---|
| RINVOQ LQ | AbbVie | 2024 | 4 |
| JAKAFI | INCYTE CORP | 2011 | 3 |
| OLUMIANT | Eli Lilly | 2018 | 3 |
| GAVRETO | RIGEL PHARMS | 2020 | 2 |
| OJJAARA | GSK | 2023 | 2 |
| OPZELURA | INCYTE CORP | 2021 | 2 |
| CIBINQO | Pfizer | 2022 | 1 |
| ANZUPGO | LEO PHARMA AS | 2025 | 1 |
| LEQSELVI | Sun Pharma | 2024 | 1 |
Drug Modality Landscape
Modalities
Routes of Administration
JAK1 is amenable to small molecule drugs, with oral options available for convenient dosing.
The absence of other modalities represents a whitespace opportunity for novel therapeutic approaches like antibodies or biologics.
Clinical Trials 707 trials
Completion by Phase
| Phase | Total | Completed | Failed | Active | Completion |
|---|---|---|---|---|---|
| Phase 1 | 197 | 101 | 25 | 70 | 80% |
| Phase 2 | 278 | 125 | 43 | 109 | 74% |
| Phase 3 | 179 | 92 | 23 | 64 | 80% |
| Phase 4 | 53 | 16 | 4 | 33 | 80% |
Top Sponsors
By Modality
Top Conditions
Phase 3 Readout Calendar Pro
8 Phase 3 trials testing approved JAK1 drugs across all sponsors.
Coverage: trials whose intervention is an approved drug targeting JAK1. Pre-approval candidates with development codes (e.g. AZD0901, MK-7240) are not yet linked. Anchored on CT.gov primary completion date.
Drug Approval Timeline (2011 - 2025)
The first JAK1 drug was approved in 2011, with the most recent approval in 2025, spanning 15 years.
Continued approvals suggest sustained interest in JAK1, but increasing competition may indicate market saturation.
Pro Intelligence Preview
Deep insights for drug target analysis
Competitive Landscape
- • 8 companies competing
- • Market share by company
Full Drug Portfolio
- • All 12 approved drugs
- • Approval dates & indications
Genetic Validation
- • Full genetic evidence table
- • Effect sizes & directions
Approval Timeline
- • Full 12-drug timeline
- • First-of-modality markers
Clinical Trials Analysis
- • Competition: High (15 sponsors)
- • White space: 4 underexplored indications
- • Success rates by condition
Full summary • All drugs • Genetic evidence • Trials • Timeline
How We Calculate These Metrics
Target Attractiveness Score
A 0-100 score based on trial activity, sponsor diversity, and completion rates. Calculated from 573 clinical trials targeting JAK1.
Completion rate: Percentage of trials that reached their planned endpoint. Trials terminated early, withdrawn, or suspended are not counted—these often indicate safety issues, lack of efficacy, or strategic pivots.
- Highly Attractive (80+): High trial activity, many sponsors, strong completion rates
- Attractive (60-79): Good trial activity and validation
- Moderate (40-59): Moderate interest from sponsors
- Low (under 40): Limited trial activity or validation concerns
Strategic Insights
Auto-generated insights based on trial analytics including competition intensity, white space opportunities, modality shifts, and failure patterns. We analyze trial sponsors, phases, indications, and outcomes.
Risk Signals
- High Competition: Many sponsors competing for this target (may reduce market opportunity)
- High Failure Risk: Low trial completion rates suggest development challenges
- Low Validation: Limited trial activity or poor outcomes indicate uncertain viability
- White Space Available: Underexplored indications present opportunities