A Phase 3 Study to Evaluate the Safety and Efficacy L606 in Participants With PH-ILD (Re-Spire)

August 31, 2026 updated by: Liquidia Technologies, Inc.

A Phase 3, Multicenter, Randomized, Double-Blinded, Placebo-Controlled Study to Evaluate the Safety and Efficacy of L606 (Treprostinil Liposome Inhalation Suspension) in Participants With Pulmonary Hypertension Associated With Interstitial Lung Disease (WHO Group 3)

The purpose of this study is to find out if L606 is safe and if it helps people with high blood pressure in the lungs (pulmonary hypertension) caused by interstitial lung disease (PH-ILD, WHO Group 3). One of the main ways the study will check this is by seeing if people can walk further in six minutes (called the "six-minute walk test"). Another important (secondary) goal is to see how long it takes for PH-ILD to get worse while people are taking L606. One way the study will measure this is by looking at the distance people walk at different times in the study on different doses of L606. Throughout the study, doctors will also closely monitor for any side effects people have to make sure L606 is safe. People who decide to join this study will be randomly (like tossing a coin) placed into one of two groups: one group will get L606 and the other group will get a placebo, which will look like L606 but will not contain any active medicine. At the end of the initial blinded portion of the study, study participants may have the opportunity to enroll in an open-label extension portion of the study where all participants will receive L606.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
344

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

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

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Australia
    • Tasmania
      • Hobart, Tasmania, Australia, 7000
        • Recruiting
        • Royal Hobart Hospital
  • Austria
      • Linz, Austria, 4020
        • Recruiting
        • Ordensklinikum Linz GmbH
  • Belgium
      • Ghent, Belgium, 9000
        • Recruiting
        • Universitair Ziekenhuis Gent
  • France
      • Le Kremlin-Bicêtre, France, 94270
        • Recruiting
        • Assistance Publique Hopitaux De Paris
  • Germany
      • Cologne, Germany, 50937
        • Recruiting
        • Universitaetsklinikum Koeln AöR
      • Giessen, Germany, 35392
        • Recruiting
        • Universitätsklinikum Giessen und Marburg - Standort Giessen
        • Contact:
      • Greifswald, Germany, 17489
        • Recruiting
        • Universitaetsmedizin Greifswald KöR
      • Hamburg, Germany, 20246
        • Recruiting
        • University Medical Center Hamburg-Eppendorf
      • Hanover, Germany, 30625
        • Recruiting
        • Medizinische Hochschule Hannover
      • Munich, Germany, 80639
        • Recruiting
        • Krankenhaus Neuwittelsbach
      • Munich, Germany, 81377
        • Recruiting
        • LMU Klinikum Muenchen AöR
  • Italy
      • Genoa, Italy, 16132
        • Recruiting
        • IRCCS Ospedale Policlinico San Martino
      • Rome, Italy, 00161
        • Recruiting
        • Azienda Ospedaliero-Universitaria Policlinico Umberto I
  • Latvia
      • Riga, Latvia, LV-1002
        • Recruiting
        • Pauls Stradins Clinical University Hospital
        • Contact:
  • Portugal
      • Almada, Portugal, 2805-267
        • Recruiting
        • Unidade Local de Saúde de Almada-Seixal E.P.E.
      • Porto, Portugal, 4050-011
        • Recruiting
        • Unidade Local De Saude De Santo Antonio E.P.E.
  • Spain
      • Barcelona, Spain, 08003
        • Recruiting
        • Hospital Del Mar
      • Barcelona, Spain, 08036
        • Recruiting
        • Hospital Clinic de Barcelona
      • Santander, Spain, 39008
        • Recruiting
        • Hospital Universitario Marqués de Valdecilla
  • United Kingdom
      • Bath, United Kingdom
        • Recruiting
        • Royal United Hospitals Bath NHS Foundation Trust
      • London, United Kingdom, NW3 2QG
        • Recruiting
        • Royal Free London NHS Foundation Trust Hospital - Royal Free Hospital
      • London, United Kingdom, SW3 6NP
        • Recruiting
        • Royal Bromptom Hospital
      • Plymouth, United Kingdom, PL6 8DH
        • Recruiting
        • University Hospitals Plymouth NHS Trust - Derriford Hospital
        • Contact:
      • Sheffield, United Kingdom, S10 2JF
        • Recruiting
        • Sheffield Teaching Hospital NHS Foundation Trust - Royal Hallamshire Hospital
  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85013
      • Scottsdale, Arizona, United States, 85258
        • Recruiting
        • Arizona Pulmonary Specialists, Ltd.
    • California
      • Los Angeles, California, United States, 90095-1690
      • San Francisco, California, United States, 94143
    • Colorado
      • Aurora, Colorado, United States, 80045
      • Denver, Colorado, United States, 80206
    • Florida
      • Tampa, Florida, United States, 33606
        • Recruiting
        • Tampa General Hospital
        • Contact:
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Recruiting
        • Northwestern University
    • Indiana
      • Indianapolis, Indiana, United States, 46260
        • Recruiting
        • St. Vincent Cardiovascular Research Institute
        • Contact:
    • New York
    • Oregon
      • Bend, Oregon, United States, 97701

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Participant is between 18 years to 80 years old.
  • Has a confirmed diagnosis of ILD based on High Resolution Computed Tomography (HRCT) chest imaging.
  • Evidence of PH as demonstrated from Right Heart Catheterization (RHC) with the following hemodynamic parameters:
  • Pulmonary vascular resistance (PVR) ≥ 320 dynes.sec/cm5 (i.e. 4 Woods Units (WU)), and
  • Mean Pulmonary Artery Pressure (mPAP) of ≥ 25 mmHg, and
  • - Pulmonary capillary wedge pressure (PCWP) or Left-Ventricular End Diastolic Pressure (LVEDP) of ≤ 15 mmHg.
  • FEV1/FVC (ratio) > 0.70.
  • 6-minute walk distance ≥ 150 meters

Exclusion Criteria:

  • PH in the updated WHO Classification Groups 1, 2, 4, or 5.
  • Has evidence of clinically significant left-sided heart disease as defined by echocardiography.
  • Participants with history of persistent/permanent or uncontrolled atrial fibrillation.
  • Participants with severe obstructive sleep apnea.
  • Has experienced exacerbation of underlying lung disease or active respiratory infection requiring antibiotics.
  • Initiation of pulmonary rehabilitation.

Note: Other protocol defined inclusion/exclusion criteria may apply.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: L606 (in combination with nebulizer)
Drug: L606
L606 is a liposomal version of treprostinil intended for delivery via oral inhalation using a study issued nebulizer.
Other Names:
  • Treprostinil Liposome Inhalation Suspension
Placebo Comparator: Placebo (in combination with nebulizer)
Drug: Placebo
Placebo will match L606 but contain no treprostinil.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Change from baseline in 6-minute walk distance (6MWD) as evaluated by the 6-minute walk test (6MWT)
Time Frame: 16 weeks
16 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Change from baseline in 6-minute walk distance (6MWD) as evaluated by the 6-minute walk test (6MWT)
Time Frame: 16 weeks
16 weeks
Time to first occurrence of: -Death -Hospitalization due to a cardio-pulmonary indication related to underlying disease -Lung transplant -Decrease in 6MWD > 15% from Baseline related to disease under study at 2 consecutive visits >1 week apart
Time Frame: 24 weeks
24 weeks
Change from baseline in 6-minute walk distance (6MWD) as evaluated by the 6-minute walk test (6MWT)
Time Frame: 24 weeks
24 weeks

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Liquidia Technologies, Inc.

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 23, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 11, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 11, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 16, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 2, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 31, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • L606-301

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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