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Pulmonary EmbolismPhase 2NAIL-ITNCT05408546

Novel α2-Antiplasmin Inactivation for Lysis of Intravascular Thrombi (NAIL-IT) Trial

A Phase 2 study testing TS23 in people with Pulmonary Embolism, run by Translational Sciences, Inc. at 13 sites in United States.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
Search all trials

Trial summary

Phase II trial of TS23 Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Pulmonary Embolism
What is being tested?
TS23
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
64 participants
Where
13 sitesUnited States
Study dates
24 May 2023to Nov 2026
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Male or female subjects, age >18 years;
  • PE involving a segmental or more proximal pulmonary artery confirmed by CTPA scan and with an onset of symptoms not more than 5 days prior to diagnosis;
  • Subject is hemodynamically stable with a systolic blood pressure (SBP) >90 mm Hg;
  • Subject has evidence of RV dysfunction as indicated by a right ventricular-to-left ventricular (RV/LV) diameter ratio > 0.9 on CTPA scan (measuring the minor axis of the right and left ventricle in the transverse plane), prior to the initiation of study drug administration.

Who cannot join

  • Subjects for whom thrombolytic therapy or thrombectomy is planned; or subjects with history of administration of thrombolytic agents within the previous 4 days;
  • Subjects receiving ≥ 48 hours of therapeutic doses of heparin or low molecular weight heparin (LMWH) or other anticoagulant therapy immediately prior to randomization;
  • Subjects with contraindications to SOC therapies such as unfractionated heparin or LMWH or oral anticoagulant, or any of the excipients (including study drug excipients);
  • Subjects who are considered at very high risk of bleeding:
  • Known coagulation disorder with history of pathologic bleeding tendencies
  • Subjects with prior intracranial hemorrhage, known arteriovenous malformation or aneurysm of the brain, or evidence of active bleeding;
Show all 19Show fewer
  • Subjects with a history of major surgery, clinically significant head trauma (in the opinion of the Principal Investigator), or stroke in the past 3 months prior to randomization;
  • Subjects with uncontrolled hypertension defined as SBP ≥180 mm Hg and/or diastolic BP (DBP)
  • ≥110 mm Hg at randomization
  • Subjects requiring concomitant dual antiplatelet therapy
  • Subjects with Creatinine Clearance (CrCL) < 30 mL/min or serum creatinine ≥ 2.5 mg/dL;
  • Subjects with hemoglobin < 8.0 g/dL;
  • Subjects with a platelet count < 100,000/µL;
  • Subjects with acute or persistent hepatitis or diagnosed active liver disease or with elevation of liver enzymes: Alanine transaminase (ALT) or aspartate transaminase (AST) ≥ 3 x upper limit of normal (ULN);
  • Subjects with known history of testing positive for Hepatitis B antigen or Hepatitis C antibody;
  • Subjects with known history of testing positive for the human immunodeficiency virus (HIV);
  • Subjects with life-expectancy < 6 months;
  • Female subjects of child bearing potential with a positive pregnancy test or who are lactating, or unwilling to use highly effective methods of contraception. Highly effective methods of birth control include combination hormonal therapy (estrogen and progresterone), contraceptives administered orally, intravaginally or transdermally, progesterone-only contraceptives administered orally, by injection or implantation, use of an intrauterine device (IUD), intrauterine hormone- releasing system (IUS), bilateral tubal occlusion, partner vasectomy or sexual abstinence;
  • Subjects currently participating in another investigational study or who have participated in an investigational drug study within 30 days (or longer depending on the half-life of the investigational drug; should allow at least five half-life of the investigational drug) prior to randomization.

Trial locations and contacts

13 sites in 1 country.

13 sites in 1 country

United States13 sites

  • Wellstar MCG Health Medical Center

    Augusta, Georgia, 30912

  • Lifebridge Health

    Baltimore, Maryland, 21215

  • Tuft University Hospital

    Boston, Massachusetts, 02116

  • Fairview Hospital

    Cleveland, Ohio, 44111

  • Cleveland Clinic

    Cleveland, Ohio, 44195

  • Henry Ford Hospital

    Detroit, Michigan, 48207

  • Texas Tech University Health Sciences Center at El Paso

    El Paso, Texas, 79430

  • Cedars Sinai Medical Center

    Los Angeles, California, 90048

  • Temple University Hospital

    Philadelphia, Pennsylvania, 19140

  • Banner University Medical Center

    Phoenix, Arizona, 85004

  • Cottage Hospital

    Santa Barbara, California, 93105

  • Banner University Medical Center - Tucson

    Tucson, Arizona, 85004

  • Wake Forest University/Atrium Health's Carolinas Medical Center

    Winston-Salem, North Carolina, 27103

Other trials in United States

About this study

Official title: Evaluation of the Safety and Thrombolytic Effects of Ascending Doses of TS23 in Subjects With Intermediate-Risk (Sub-Massive) Acute Pulmonary Embolism

Phase II trial of TS23

Read the detailed description

Evaluation of safety and thrombolytic effect of ascending doses of TS23 in subjects with intermediate-risk (sub-massive) acute pulmonary embolism (PE)

Being tested
TS23, Placebo
Medical subject headings
Pulmonary Embolism

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • TS23Drug

    Monoclonal antibody to a2-antiplasmin

  • PlaceboDrug

    Placebo

Study groups in NCT05408546
Study groupRoleWhat they receive
PlaceboPlacebo comparatorPlacebo + standard of care (SOC) anticoagulation
Receives: Drug: Placebo
Low dose TS23ExperimentalTS23 low dose + SOC anticoagulation
Receives: Drug: TS23
Intermediate dose TS23ExperimentalTS23 medium dose + SOC anticoagulation
Receives: Drug: TS23
Higher dose TS23ExperimentalTS23 highest dose + SOC anticoagulation
Receives: Drug: TS23

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. RV/LV

    Ratio of the right to left ventricle dimensions on CT perfusion angiogram (CTPA)

    Measured: 48 hours after treatment

  2. Safety- Bleeding

    Frequency of major or clinically significant bleeding

    Measured: within 7 days of treatment

Secondary outcomes (1)

  1. Thrombus dissolution

    Change in modified Miller Score

    Measured: 48 hours after treatment

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted7 Jun 2022
  2. Study start24 May 2023
  3. Primary completion31 Aug 2026 (estimated)
  4. Study completionNov 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
64 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05408546
Sponsor's protocol ID
TS23-U201
Acronym
NAIL-IT
Status last verified
Jun 2026
First submitted
21 May 2022
Last updated
1 Jul 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • Singh S, Houng A, Reed GL. Releasing the Brakes on the Fibrinolytic System in Pulmonary Emboli: Unique Effects of Plasminogen Activation and alpha2-Antiplasmin Inactivation. Circulation. 2017 Mar 14;135(11):1011-1020. doi: 10.1161/CIRCULATIONAHA.116.024421. Epub 2016 Dec 27.

    PubMed 28028005

  • Singh S, Houng AK, Reed GL. Venous stasis-induced fibrinolysis prevents thrombosis in mice: role of alpha2-antiplasmin. Blood. 2019 Sep 19;134(12):970-978. doi: 10.1182/blood.2019000049. Epub 2019 Aug 8.

    PubMed 31395599

  • Reed GL, Houng AK, Wang D. Microvascular thrombosis, fibrinolysis, ischemic injury, and death after cerebral thromboembolism are affected by levels of circulating alpha2-antiplasmin. Arterioscler Thromb Vasc Biol. 2014 Dec;34(12):2586-93. doi: 10.1161/ATVBAHA.114.304530. Epub 2014 Sep 25.

    PubMed 25256235

  • Houng AK, Wang D, Reed GL. Reversing the deleterious effects of alpha2-antiplasmin on tissue plasminogen activator therapy improves outcomes in experimental ischemic stroke. Exp Neurol. 2014 May;255:56-62. doi: 10.1016/j.expneurol.2014.02.009. Epub 2014 Feb 18.

    PubMed 24556477

  • Cesarman-Maus G, Hajjar KA. Molecular mechanisms of fibrinolysis. Br J Haematol. 2005 May;129(3):307-21. doi: 10.1111/j.1365-2141.2005.05444.x.

    PubMed 15842654

  • Meyer G, Vicaut E, Konstantinides SV. Fibrinolysis for intermediate-risk pulmonary embolism. N Engl J Med. 2014 Aug 7;371(6):581-2. doi: 10.1056/NEJMc1406283. No abstract available.

    PubMed 25099590

  • Aghayev A, Furlan A, Patil A, Gumus S, Jeon KN, Park B, Bae KT. The rate of resolution of clot burden measured by pulmonary CT angiography in patients with acute pulmonary embolism. AJR Am J Roentgenol. 2013 Apr;200(4):791-7. doi: 10.2214/AJR.12.8624.

    PubMed 23521450

  • Meinel FG, Nance JW Jr, Schoepf UJ, Hoffmann VS, Thierfelder KM, Costello P, Goldhaber SZ, Bamberg F. Predictive Value of Computed Tomography in Acute Pulmonary Embolism: Systematic Review and Meta-analysis. Am J Med. 2015 Jul;128(7):747-59.e2. doi: 10.1016/j.amjmed.2015.01.023. Epub 2015 Feb 11.

    PubMed 25680885

  • Ouriel K, Ouriel RL, Lim YJ, Piazza G, Goldhaber SZ. Computed tomography angiography with pulmonary artery thrombus burden and right-to-left ventricular diameter ratio after pulmonary embolism. Vascular. 2017 Feb;25(1):54-62. doi: 10.1177/1708538116645056. Epub 2016 Jul 9.

    PubMed 27090586

  • Zuo Z, Yue J, Dong BR, Wu T, Liu GJ, Hao Q. Thrombolytic therapy for pulmonary embolism. Cochrane Database Syst Rev. 2021 Apr 15;4(4):CD004437. doi: 10.1002/14651858.CD004437.pub6.

    PubMed 33857326

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing TS23 in people with Pulmonary Embolism, run by Translational Sciences, Inc. at 13 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 1 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 13 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

RV/LV (time frame: 48 hours after treatment). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05408546, which also lists 10 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Jul 2026.

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