Antithrombin III Inhibitors
14 drugsAbout Antithrombin III
Antithrombin III (SERPINC1) is a serine protease inhibitor that regulates blood coagulation by neutralizing thrombin, factor Xa, and factor IXa. This prevents excessive clot formation, maintaining blood fluidity and preventing thrombosis.
Human genetic studies provide strong validation for antithrombin as a therapeutic target (score 0.99). Loss-of-function variants are associated with reduced antithrombin III activity, hereditary antithrombin deficiency, and venous thrombosis (score 0.76), suggesting activation is likely beneficial.
Antithrombin III is targeted by 14 FDA-approved small molecule drugs, including Heparin Sodium. These drugs, developed by companies like Pfizer and Fresenius Kabi, are primarily used in cardiovascular applications.
Antithrombin III Genetic Evidence Strong
Strong genetic evidence supports antithrombin as a drug target, with a maximum score of 0.99.
The strong genetic support suggests a higher probability of clinical success for antithrombin-targeting drugs.
💡 Why activation?
- • Gain-of-function variants reduce disease risk — enhancing activity may help
- • 100% directional consistency across 1 traits
- • Strong signal in phenotype pathways
Cross-Disease Effects
Trade-off: LowDirection of Effect
100% alignedEvidence Across Diseases
20 totalGWAS and other genetic studies link SERPINC1 to 25 diseases.
🔗 Colocalization Evidence 20 strong
max H4: 1.00eQTL/pQTL signals for SERPINC1 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 Antithrombin III Drugs
Six companies have approved drugs targeting antithrombin III, with Pfizer and Fresenius Kabi as top players.
The concentrated market suggests high entry barriers, requiring differentiated strategies for new entrants.
Antithrombin III Drug Modality Landscape
Modalities
Routes of Administration
Antithrombin III is druggable by small molecules, though no oral formulations are currently approved.
Exploring alternative modalities like antibodies or fusion proteins could provide a competitive advantage.
Antithrombin III Clinical Trials 189 trials
Phase 1-4 trials started in 2008 or later that test an FDA-approved drug acting on Antithrombin III. Source: ClinicalTrials.gov. How we count
Completion by Phase
| Phase | Total | Completed | Stopped | Active | Completion |
|---|---|---|---|---|---|
| Phase 1 | 26 | 19 | 5 | 2 | 79% |
| Phase 2 | 45 | 21 | 15 | 9 | 58% |
| Phase 3 | 50 | 28 | 11 | 11 | 72% |
| Phase 4 | 68 | 43 | 12 | 12 | 78% |
Top Sponsors
By Modality
Top Conditions
Top Drugs
Antithrombin III Drug Approval Timeline (1972 - 2023)
Venous Thrombosis
Venous Thrombosis
HEPARIN SODIUM IN SODIUM CHLORIDE INJECTION is indicated ...
Venous Thrombosis
Venous Thrombosis
Venous Thrombosis
The first drug was approved in 1972, with the most recent approval in 2023, spanning 52 years.
The long approval history indicates a mature market, suggesting incremental innovation opportunities.
Pro Intelligence Preview
Deep insights for drug target analysis
Competitive Landscape
- • 7 companies competing
- • Market share by company
Full Drug Portfolio
- • All 14 approved drugs
- • Approval dates & indications
Genetic Validation
- • Full genetic evidence table
- • Effect sizes & directions
Approval Timeline
- • Full 14-drug timeline
- • First-of-modality markers
Clinical Trials Analysis
- • Sponsors: 157 (31 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 Antithrombin III. A trial counts if an approved drug acting on Antithrombin III 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.