Cardiovascular · Clinical trials
Pulmonary Embolism 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 pulmonary embolism — and why its trials are hard
Pulmonary embolism (PE) is obstruction of the pulmonary arteries, usually by thrombus that has embolized from deep veins of the legs or pelvis, and it is the most serious manifestation of venous thromboembolism. Presentations range from asymptomatic subsegmental clots to massive PE with obstructive shock and sudden death. Risk stratification drives management: hemodynamic status, right-ventricular dysfunction on imaging, and cardiac biomarkers (troponin, natriuretic peptides) separate low-risk, intermediate-risk, and high-risk (massive) PE. Anticoagulation is the cornerstone for essentially all confirmed PE. Direct oral anticoagulants (rivaroxaban, apixaban, edoxaban, dabigatran) have largely replaced warfarin for most patients because of comparable efficacy with less bleeding and no routine monitoring, validated in the EINSTEIN-PE, AMPLIFY, and Hokusai-VTE trials. High-risk PE with shock warrants systemic thrombolysis or, when contraindicated, catheter-directed therapy or surgical embolectomy. Intermediate-risk PE is managed with anticoagulation and close monitoring; routine full-dose thrombolysis is avoided because of bleeding risk. Duration of anticoagulation depends on whether the PE was provoked, unprovoked, or cancer-associated.
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 |
|---|---|---|---|---|---|
| Rivaroxaban (Xarelto) | 2012 (DVT/PE treatment) | Acute treatment and secondary prevention of PE/VTE (single-drug oral regimen) | EINSTEIN-PE (NEJM 2012) | Recurrent symptomatic venous thromboembolism (non-inferiority) | Recurrent VTE 2.1% rivaroxaban vs 1.8% standard therapy (HR 1.12, non-inferior); major bleeding significantly reduced (1.1% vs 2.2%, HR 0.49) |
| Apixaban (Eliquis) | 2014 (DVT/PE treatment) | Acute treatment and extended prevention of PE/VTE | AMPLIFY (NEJM 2013) | Recurrent VTE or VTE-related death (non-inferiority) | Primary event 2.3% apixaban vs 2.7% conventional therapy (RR 0.84, non-inferior); major bleeding markedly lower (0.6% vs 1.8%, RR 0.31) |
| Edoxaban (Savaysa (Lixiana)) | 2015 | Treatment of PE/VTE after initial parenteral heparin | Hokusai-VTE (NEJM 2013) | Recurrent symptomatic VTE (non-inferiority) | Recurrent VTE 3.2% edoxaban vs 3.5% warfarin (non-inferior); clinically relevant bleeding reduced (8.5% vs 10.3%) |
| Alteplase (systemic thrombolysis) (Activase) | 1990 (massive PE indication) | High-risk (massive) PE with hemodynamic instability | Registration and supportive RCTs; PEITHO (NEJM 2014) informs intermediate-risk use | Hemodynamic stabilization / prevention of death or decompensation | Rapidly restores pulmonary perfusion and reduces death/decompensation in high-risk PE; reserved for massive PE because of substantial major and intracranial bleeding risk |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in pulmonary embolism development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| Tenecteplase (full-dose thrombolysis in intermediate-risk PE) — PEITHO (NEJM 2014) | Reduced the composite of death or hemodynamic decompensation at 7 days (2.6% vs 5.6%) but did NOT improve mortality and significantly increased major extracranial bleeding (6.3% vs 1.2%) and hemorrhagic stroke (2.0% vs 0.2%) | Bleeding harm, especially intracranial hemorrhage in older patients, offset the modest hemodynamic benefit, so routine full-dose thrombolysis is not recommended for intermediate-risk PE |
| Idraparinux (long-acting factor Xa inhibitor) — Van Gogh PE / Cassiopea programs | Once-weekly idraparinux was inferior/less effective for symptomatic PE and raised bleeding and reversibility concerns | Long half-life with no reliable antidote and unfavorable efficacy-safety balance halted development for PE |
Choosing the right endpoint
Primary endpoints that matter in pulmonary embolism trials
- Recurrent symptomatic VTE — Primary efficacy endpoint of anticoagulation trials (EINSTEIN-PE, AMPLIFY, Hokusai-VTE), usually tested for non-inferiority vs heparin/warfarin
- Major bleeding / clinically relevant non-major bleeding — Central safety endpoint; DOAC advantage over warfarin is driven largely by lower bleeding
- Death or hemodynamic decompensation — Composite used in intermediate-risk thrombolysis trials such as PEITHO
- All-cause and PE-related mortality — Hard outcome; thrombolysis has not shown a mortality benefit in intermediate-risk PE
- RV dysfunction / recovery — Imaging and biomarker measures used for risk stratification and as secondary endpoints
How iNGENū runs pulmonary embolism 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
Pulmonary Embolism clinical trials — FAQs
Are DOACs as effective as warfarin for pulmonary embolism?
Should every patient with PE receive clot-busting thrombolysis?
How long do patients stay on anticoagulation after a PE?
Ready to discuss your pulmonary embolism trial?
Talk to our physician-led team about an FDA-ready, cost-efficient trial design.
Request a proposal