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

June 29, 2026 updated by: Translational Sciences, Inc.

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

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

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

Study Type

Interventional

Enrollment (Estimated)

64

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85004
        • Banner University Medical Center
      • Tucson, Arizona, United States, 85004
        • Banner University Medical Center - Tucson
    • California
      • Los Angeles, California, United States, 90048
        • Cedars Sinai Medical Center
      • Santa Barbara, California, United States, 93105
        • Cottage Hospital
    • Georgia
      • Augusta, Georgia, United States, 30912
        • Wellstar MCG Health Medical Center
    • Maryland
      • Baltimore, Maryland, United States, 21215
        • LifeBridge Health
    • Massachusetts
      • Boston, Massachusetts, United States, 02116
        • Tuft University Hospital
    • Michigan
      • Detroit, Michigan, United States, 48207
        • Henry Ford Hospital
    • North Carolina
      • Winston-Salem, North Carolina, United States, 27103
        • Wake Forest University/Atrium Health's Carolinas Medical Center
    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Cleveland Clinic
      • Cleveland, Ohio, United States, 44111
        • Fairview Hospital
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19140
        • Temple University Hospital
    • Texas
      • El Paso, Texas, United States, 79430
        • Texas Tech University Health Sciences Center at El Paso

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female subjects, age >18 years;
  2. 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;
  3. Subject is hemodynamically stable with a systolic blood pressure (SBP) >90 mm Hg;
  4. 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.

Exclusion Criteria:

  1. Subjects for whom thrombolytic therapy or thrombectomy is planned; or subjects with history of administration of thrombolytic agents within the previous 4 days;
  2. Subjects receiving ≥ 48 hours of therapeutic doses of heparin or low molecular weight heparin (LMWH) or other anticoagulant therapy immediately prior to randomization;
  3. Subjects with contraindications to SOC therapies such as unfractionated heparin or LMWH or oral anticoagulant, or any of the excipients (including study drug excipients);

  4. Subjects who are considered at very high risk of bleeding:

    1. Known coagulation disorder with history of pathologic bleeding tendencies
    2. Subjects with prior intracranial hemorrhage, known arteriovenous malformation or aneurysm of the brain, or evidence of active bleeding;
    3. 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;

    4. Subjects with uncontrolled hypertension defined as SBP ≥180 mm Hg and/or diastolic BP (DBP)

      ≥110 mm Hg at randomization

    5. Subjects requiring concomitant dual antiplatelet therapy
  5. Subjects with Creatinine Clearance (CrCL) < 30 mL/min or serum creatinine ≥ 2.5 mg/dL;
  6. Subjects with hemoglobin < 8.0 g/dL;
  7. Subjects with a platelet count < 100,000/µL;
  8. 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);
  9. Subjects with known history of testing positive for Hepatitis B antigen or Hepatitis C antibody;
  10. Subjects with known history of testing positive for the human immunodeficiency virus (HIV);
  11. Subjects with life-expectancy < 6 months;
  12. 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;
  13. 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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Placebo + standard of care (SOC) anticoagulation
Drug: Placebo
Placebo
Experimental: Low dose TS23
TS23 low dose + SOC anticoagulation
Drug: TS23
Monoclonal antibody to a2-antiplasmin
Experimental: Intermediate dose TS23
TS23 medium dose + SOC anticoagulation
Drug: TS23
Monoclonal antibody to a2-antiplasmin
Experimental: Higher dose TS23
TS23 highest dose + SOC anticoagulation
Drug: TS23
Monoclonal antibody to a2-antiplasmin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
RV/LV
Time Frame: 48 hours after treatment
Ratio of the right to left ventricle dimensions on CT perfusion angiogram (CTPA)
48 hours after treatment
Safety- Bleeding
Time Frame: within 7 days of treatment
Frequency of major or clinically significant bleeding
within 7 days of treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Thrombus dissolution
Time Frame: 48 hours after treatment
Change in modified Miller Score
48 hours after treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Translational Sciences, Inc.

Investigators

  • Principal Investigator: Nils Nickel, MD, University of Texas

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 24, 2023

Primary Completion (Estimated)

August 31, 2026

Study Completion (Estimated)

November 1, 2026

Study Registration Dates

First Submitted

May 21, 2022

First Submitted That Met QC Criteria

June 3, 2022

First Posted (Actual)

June 7, 2022

Study Record Updates

Last Update Posted (Actual)

July 1, 2026

Last Update Submitted That Met QC Criteria

June 29, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TS23-U201

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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