AzTrials
AzTrials

Pulmonary Arterial HypertensionPhase 2NCT05343637

A Dose Escalation Study to Evaluate the Effect of RT234 in Subjects With Pulmonary Arterial Hypertension

A Phase 2 study testing Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI) in people with Pulmonary Arterial Hypertension, run by Respira Therapeutics, Inc. at 3 sites in Australia.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

This multicenter, open label, Phase 2a study is designed to evaluate the effect of inhaled RT234 delivered in a dose escalation manner on the change in pulmonary vascular resistance (PVR) in subjects with Pulmonary Arterial Hypertension (PAH) undergoing Right heart catheterization (RHC). Read more about this study

Who is it for?
Ages 18 to 80 years
Conditions the study is for
Pulmonary Arterial Hypertension
What is being tested?
Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
14 participants
Where
3 sitesAustralia
Study dates
30 Jul 2019to 17 Jan 2020
Phase
Phase 2
Are there results?
None posted in the registry

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 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Between 18 and 80 years of age, inclusive.
  • Diagnosis of RHC-confirmed WHO Group 1 PAH in any of the following three categories: Idiopathic, primary or familial pulmonary arterial hypertension (IPAH, PPH, or FPAH); OR PAH associated with one of the following connective tissue diseases (CTD):
  • Systemic sclerosis (scleroderma)
  • Limited scleroderma
  • Mixed connective tissue disease
  • Systemic lupus erythematosus
Show all 19Show fewer
  • Overlap syndrome
  • Other autoimmune disorders;
  • OR PAH associated with:
  • Human immunodeficiency virus (HIV) infection with no evidence of opportunistic infection in the preceding 6 months;
  • Simple, congenital systemic-to-pulmonary shunts at least one-year post-surgical repair.
  • Exposure to legal drugs, chemicals and toxins, such as fenfluramine, derivatives, other anorexigens, toxic rapeseed oil or L-tryptophan. Subjects with PAH associated with illegal drug use, such as methamphetamine, were excluded.
  • Previous diagnosis with PAH with the following conditions:
  • Stable PAH without significant adjustments of disease-specific background PAH therapy, at least 3 months prior to RHC procedure;
  • If on corticosteroids, has been receiving a stable dose of ≤ 20 mg/day of prednisone (or equivalent dose of other corticosteroid) for at least 30 days prior to RHC procedure.
  • Pulmonary Function Tests within 24 months prior to RHC procedure that fulfilled the following criteria (pulmonary function; (PFT may be assessed at Screening if historical PFT results are not available):
  • Forced Expiratory volume in one second (FEV1) ≥ 60% predicted (pre-bronchodilators);
  • FEV1/ forced expiratory vital capacity (FVC) ≥ 60% (pre-bronchodilators);
  • FVC ≥ 60% predicted.

Who cannot join

  • Baseline systemic hypotension, defined as MAP < 50 mmHg or systolic blood pressure (SBP)< 90 mmHg at Screening.
  • Requirement of intravenous inotropes within 30 days prior to RHC procedure.
  • Use of oral, topical or inhaled nitrates within 14 days prior to RHC procedure.
  • Uncontrolled systemic hypertension: SBP > 160 mmHg or diastolic blood pressure (DBP) >100 mmHg at Screening.
  • History of portal hypertension or chronic liver disease, including active viral replication of hepatitis B and/or hepatitis C or classified as having moderate to severe hepatic impairment (Child-Pugh Class B-C).
  • Chronic renal insufficiency as defined by serum creatinine > 2.5 mg/dL at Screening or requires dialysis.
Show all 15Show fewer
  • History of atrial septostomy.
  • Unrepaired congenital heart disease (CHD).
  • Pericardial constriction; restrictive or congestive cardiomyopathy.
  • History of left ventricular ejection fraction (EF) < 40% by multiple gated acquisition scan (MUGA), angiography, echocardiography, or cardiac magnetic resonance imaging (CMRI).
  • Symptomatic coronary disease with demonstrable ischemia.
  • Poorly controlled asthma defined by active wheezing and/or cough at the time of Screening or day of participation in Parts A and B.
  • Clinically significant intercurrent illness (including lower respiratory tract infection) or clinically significant surgery within 30 days prior to study drug administration.
  • Clinical RHC < 14 days prior to Screening.
  • History of non-arteritic anterior ischemic optic neuropathy (NAION) or retinitis pigmentosa.

Trial locations and contacts

3 sites in 1 country.

Australia3 sites

  • St Vincent's Hospital

    Darlinghurst, New South Wales, 2010

  • Royal Hobart Hospital

    Hobart, Tasmania, 7000

  • The Alfred Hospital

    Melbourne, Victoria, 3004

Other trials in Australia

About this study

Official title: A Phase 2a, Dose Escalation Study to Evaluate the Effect of RT234 on Cardiopulmonary Hemodynamics in Subjects With Pulmonary Arterial Hypertension

This multicenter, open label, Phase 2a study is designed to evaluate the effect of inhaled RT234 delivered in a dose escalation manner on the change in pulmonary vascular resistance (PVR) in subjects with Pulmonary Arterial Hypertension (PAH) undergoing Right heart catheterization (RHC).

This study is also known as Vardenafil Inhaled for Pulmonary Arterial Hypertension PRN Phase 2a (VIPAH-PRN 2a) study

Read the detailed description

The drawbacks of current therapies and the lack of an approved as needed (PRN) treatment for PAH that improves exercise ability and quality of life, form the basis for development of RT234 (inhaled vardenafil). The current study will identify the effective dose(s) of RT234 to acutely improve pulmonary vascular hemodynamics when delivered in a dose escalation manner in subjects with World Health Organization (WHO) Group 1 PAH undergoing RHC. In addition, this study will also provide valuable efficacy and safety insights into the interactions between RT234 and background disease-specific PAH therapy on pulmonary hemodynamics and right heart function.

Being tested
Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI)
Keywords
Pulmonary Arterial Hypertension, Familial Primary Pulmonary Hypertension, Vascular Diseases, Cardiovascular Diseases, Hypertension, Pulmonary, Lung Diseases, Respiratory Tract Diseases, Vardenafil Dihydrochloride, Vasodilator Agents, Phosphodiesterase 5 Inhibitors, Phosphodiesterase Inhibitors, Enzyme Inhibitors, Molecular Mechanisms of Pharmacological Action
Medical subject headings
Pulmonary Arterial Hypertension, Familial Primary Pulmonary Hypertension, Vascular Diseases, Cardiovascular Diseases, Hypertension, Pulmonary, Lung Diseases, Respiratory Tract Diseases

What participants receive

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

  • Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI)Combination product

    Also called vardenafil inhalation powder, inhaled vardenafil

    RT234 is a drug/device combination product composed of vardenafil hydrochloride as the drug constituent and will utilize RS01 DPI device.

Study groups in NCT05343637
Study groupRoleWhat they receive
RT234 - Cohort 1ExperimentalParticipants will receive RT234 as 0.2 mg and 0.6 mg
Receives: Combination Product: Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI)
RT234 - Cohort 2ExperimentalParticipants will receive RT234 as 0.6 mg and 1.2 mg
Receives: Combination Product: Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI)
RT234 - Cohort 3ExperimentalParticipants will receive RT234 as 1.2 mg and 2.4 mg
Receives: Combination Product: Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI)

What is being measured

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

  1. Evaluation of adverse events (AEs)

    Evaluation of AEs will be measured by clinical examination and participant self-reporting. Known or possible adverse events include headache, lightheadedness and cough.

    Measured: Screening to Day 30

  2. Peak plasma concentration (Cmax)

    Change in Cmax at each dose level on Day 1.

    Measured: At baseline, 5, 15, 30, 45 and 60 minutes post-end of inhalation for the first RT234 dose and at 5, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-end of inhalation for the second RT234 dose.

  3. Time to peak plasma concentration (Tmax)

    Change in Tmax at each dose level on Day 1.

    Measured: At baseline, 5, 15, 30, 45 and 60 minutes post-end of inhalation for the first RT234 dose and at 5, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-end of inhalation for the second RT234 dose.

  4. Area under the plasma concentration versus time curve (AUC)

    Change in AUC at each dose level on Day 1.

    Measured: At baseline, 5, 15, 30, 45 and 60 minutes post-end of inhalation for the first RT234 dose and at 5, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-end of inhalation for the second RT234 dose.

  5. Terminal half-life

    Change in terminal half-life at each dose level on Day 1.

    Measured: At baseline, 5, 15, 30, 45 and 60 minutes post-end of inhalation for the first RT234 dose and at 5, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-end of inhalation for the second RT234 dose.

  6. Change in pulmonary vascular resistance (PVR)

    Maximal change from baseline in PVR assessed at the time by right heart catheterisation (RHC).

    Measured: At baseline, 5, 15, 30, 45 and 60 minutes post-end of inhalation for the first RT234 dose and at 5, 15, 30, 45, 60, 75, 90, 105 and 120 minutes post-end of inhalation for the second RT234 dose on Day 1.

Timeline

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

  1. First posted25 Apr 2022
  2. Study start30 Jul 2019
  3. Primary completion17 Jan 2020
  4. Study completion17 Jan 2020

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
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
14 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05343637
Sponsor's protocol ID
RT234-CL201
Other IDs
ACTRN12619001178134
Status last verified
Mar 2026
First submitted
4 Apr 2022
Last updated
6 Apr 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Drug: RT234 - vardenafil inhalation powder; Device: RS01 dry powder inhaler (RS01 DPI) in people with Pulmonary Arterial Hypertension, run by Respira Therapeutics, Inc. at 3 sites in Australia.

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 19 inclusion and 15 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: finished, as of the sponsor's last update on 6 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in Australia. 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. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Evaluation of adverse events (AEs) (time frame: Screening to Day 30). The study lists 6 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 NCT05343637.

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 6 Apr 2026.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in