Pulmonary Arterial HypertensionPhase 3IMPROVE-PAHNCT07365332
An Adaptive Program of IKT-001 in Pulmonary Arterial Hypertension (PAH)
A Phase 3 study testing IKT-001 in people with Pulmonary Arterial Hypertension, run by Inhibikase Therapeutics at 43 sites in 14 countries.
Trial summary
This is an adaptive, 2-part, randomized, multicenter, double-blind, placebo-controlled, parallel-group study designed to evaluate the efficacy and safety of IKT-001 in adult participants with WHO Group 1 PAH. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Pulmonary Arterial Hypertension
- What is being tested?
- IKT-001
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 486 participants
- Where
- 43 sitesin 14 countries
- Study dates
- 23 Apr 2026to Dec 2029
- Phase
- Phase 3
- 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 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Documented diagnosis of WHO PAH Group 1 in any of the following subtypes:
- Idiopathic PAH
- Heritable PAH
- Drug/toxin-induced PAH
- PAH associated with connective tissue disease (CTD)
- PAH associated with simple, congenital systemic-to-pulmonary shunts at least 1 year following repair
Show all 11Show fewer
- Men and women 18 and 75 years of age (inclusive)
- Must have a body mass index (BMI) of ≥18.5 kg/m^2 and ≤35.0 kg/m^2 at screening.
- Baseline RHC performed during the Screening Period documenting a PVR of ≥ 400 dyn/sec/cm^5 ; pulmonary capillary wedge pressure (PCWP) ≤15 mmHg and mean pulmonary artery pressure (mPAP) >20 mmHg. PVR enrichment criteria to ensure population baseline PVR >700 dynes/sec/cm^5
- On stable doses of background PAH therapy including endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostacyclins, and soluble guanylate cyclase stimulators for ≥90 days prior to screening. Current use of sotatercept is not permitted.
- 6MWD ≥ 100 and ≤ 475 m
Who cannot join
- Diagnosis of PAH WHO Groups 2, 3, 4, or 5.
- Diagnosis of the following PAH Group 1 subtypes: human immunodeficiency virus (HIV)-associated PAH, PAH associated with portal hypertension, schistosomiasis-associated PAH, and pulmonary veno-occlusive disease.
- Any of the following blood pressure-related values or abnormalities: Uncontrolled systemic hypertension as evidenced by sitting systolic BP >160 mmHg or sitting diastolic BP >100 mmHg at screening, Baseline systolic BP <90 mmHg at screening, Syncope within 3 months prior to screening
- History of restrictive, constrictive, or congestive cardiomyopathy.
- ECG with Fridericia's corrected QT interval (QTcF) ≥ 450 msec in males or ≥ 470 msec in females at screening or ≥500 msec in the presence of a right bundle branch block.
- Personal or family history of long QT syndrome or sudden cardiac death.
Show all 31Show fewer
- Presence of a CardioMEMS device or any other implanted hemodynamic monitoring device.
- Forced vital capacity (FVC) <70 percent on pulmonary function test (PFT) performed no more than 6 months prior to screening; or if FVC is 60 percent to 69 percent, must have a chest computed tomography scan within 12 months with no more than mild interstitial lung disease.
- History of atrial fibrillation or atrial flutter.
- History of cerebrovascular accident, intracranial hemorrhage, or subdural hematoma at anytime, or a fall associated with head trauma within 3 months of screening.
- Acutely decompensated right heart failure within 30 days prior to screening, as per investigator assessment.
- Clinically significant ischemic, valvular, constrictive heart disease, or heart failure with preserved ejection fraction in the opinion of the investigator.
- History of pneumonectomy.
- Untreated or inadequately treated (in the opinion of the investigator) obstructive sleep apnea.
- Acute or chronic hepatitis B or C infection, defined as:
- Hepatitis B virus: a positive hepatitis B surface antigen test or a positive hepatitis B core antibody test with detectable DNA
- Hepatitis C virus (HCV): a positive hepatitis C antibody test with detectable HCV ribonucleic acid (RNA).Participants with a positive hepatitis C antibody test, but no detectable HCV RNA who completed treatment with direct-acting antivirals may be considered after discussion with the medical monitor.
- History of or currently diagnosed with a bleeding disorder, including but not limited to hemophilia, von Willebrand disease, thrombocytopenia, or significant bleeding history defined as any bleeding event requiring medical intervention.
- Received treatment with any of the following excluded medications:
- Currently receiving strong cytochrome P450 (CYP) 3A inducers or CYP3A inhibitors (except for topical administration)
- Currently receiving or anticipated need to receive any anticoagulant (e.g., heparins, vitamin K antagonists, direct oral anticoagulants, or direct thrombin inhibitors).
- Current use of sotatercept. Note: participants who previously received sotatercept may be considered if the last dose administered was >6 months prior to screening, participant had no significant bleeding events while on sotatercept.
- Initiation of an exercise program for cardiopulmonary rehabilitation within 90 days prior to screening or planned initiation during the study (participants who are stable in the maintenance phase of a program and who will continue for the duration of the study are eligible).
- History of atrial septostomy within 180 days prior to screening.
- Current participation in another investigational clinical trial and/or receipt of any investigational medication within 90 days prior to screening.
- Previous randomization into this or another IKT-001 study.
- Any social, behavioral, or medical reason that would preclude completion of the study, in the judgement of the investigator.
- Currently lactating, pregnant or planning on becoming pregnant during the study.
- Prior receipt of a solid organ transplant or stem cell transplant.
- Planned surgery that would require any study drug interruption or interfere with study assessments during the study (minor procedures may be allowed in consultation with the medical monitor).
- Malignancy within the last 5 years prior to consent except completely treated non-metastatic-basal cell, squamous cell, in situ cervical cancer, and clinically localized National Comprehensive Cancer Network very low to low risk prostate cancer under active surveillance.
Trial locations and contacts
43 sites in 14 countries. Contact the study team or a site near you to ask about taking part.
43 sites in 14 countries
United States15 sites, 15 recruiting
- Recruiting
University of Colorado Anschutz Medical Campus
Aurora, Colorado, 80045
- Recruiting
Cedars Sinai
Beverly Hills, California, 90211
- Recruiting
Tufts Medical Center
Boston, Massachusetts, 02111
- Recruiting
University of Cincinnati
Cincinnati, Ohio, 45267
- Recruiting
UT Southwestern Medical Center
Dallas, Texas, 75390
- Recruiting
Duke University
Durham, North Carolina, 27710
- Recruiting
University of Kansas Medical Center
Kansas City, Kansas, 66103
- Recruiting
Norton Healthcare
Louisville, Kentucky, 40202
- Recruiting
Vanderbilt University Medical Center
Nashville, Tennessee, 37232-7610
- Recruiting
NYU Langone Health
New York, New York, 10016
- Recruiting
Jeffrey S. Sager, MD Medical Corporation
Santa Barbara, California, 93105
- Recruiting
Arizona Pulmonary Specialists, LTD
Scottsdale, Arizona, 85258
- Recruiting
Washington University School of Medicine
St Louis, Missouri, 63110
- Recruiting
Lundquist at Harbor UCLA
Torrance, California, 90502
- Recruiting
Westchester Medical Center
Valhalla, New York, 10595
Spain10 sites, 10 recruiting
- Recruiting
Hospital Clínic de Barcelona
Barcelona, Barcelona, 08036
- Recruiting
Hospital Universitari Vall d'Hebron
Barcelona, Catalonia, 08035
- Recruiting
Hospital Universitario Doce de Octubre
Madrid, Madrid, 28041
- Recruiting
Hospital Universitario la Paz
Madrid, Madrid, 28046
- Recruiting
Hospital Universitario Virgen de la Victoria
Málaga, Andalusia, 29010
- Recruiting
Hospital Costa del Sol
Marbella, Malaga, 29603
- Recruiting
Hospital Universitario Marqués De Valdecilla
Santander, Cantabria, 39008
- Recruiting
Hospital Universitario Virgen Macarena
Seville, Sevilla, 41009
- Recruiting
Hospital General Universitario de Toledo
Toledo, Toledo, 45007
- Recruiting
Hospital Universitari i Politecnic La Fe de Valencia
Valencia, Valencia, 46026
New Zealand3 sites, 3 recruiting
- Recruiting
Auckland City Hospital
Auckland, Auckland, 1051
- Recruiting
University of Otago Christchurch
Christchurch, Canterbury, 8011
- Recruiting
Te Whato Ora, Health New Zealand, Waikato Hospital
Hamilton, Waikato Region, 3204
United Kingdom3 sites, 3 recruiting
- Recruiting
Royal Papworth Hospital
Cambridge, Cambridgeshire, CB2 0AY
- Recruiting
Golden Jubilee National Hospital
Glasgow, West Dunbartonshire, G81 4DY
- Recruiting
Imperial College Healthcare NHS Trust
London, W12 0HS
France2 sites, 2 recruiting
- Recruiting
Hôpital Bicêtre
Le Kremlin-Bicêtre, France, 94270
- Recruiting
CHRU Strasbourg
Strasbourg, Grand Est, 67091
South Korea2 sites, 2 recruiting
- Recruiting
Chonnam National University Hospital
Gwangju, 61469
- Recruiting
Samsung Medical Center
Seoul, 06351
Argentina1 site, 1 recruiting
- Recruiting
Sanatorio de la Trinidad Palermo
Buenos Aires, Buenos Aires, 1425
Australia1 site, 1 recruiting
- Recruiting
Pulmonary Hypertension Research Queensland PHRQ
Auchenflower, Queensland, 4066
Belgium1 site, 1 recruiting
- Recruiting
Hôpital Universitaire de Bruxelles - Erasme
Anderlecht, Brussels Capital, 1070
Canada1 site, 1 recruiting
- Recruiting
University of Alberta Hospital
Edmonton, Alberta, T6G 2B7
Germany1 site, 1 recruiting
- Recruiting
Medizinische Hochschule Hannover, Abteilung Pneumologie und Infektiologie
Hanover, Lower Saxony, 30625
Italy1 site, 1 recruiting
- Recruiting
Fondazione IRCCS San Gerardo dei Tintori
Monza, Monza and Brianza, 20900
Netherlands1 site, 1 recruiting
- Recruiting
Amsterdam UMC site VUMC
Amsterdam, North Holland, 1081 BT
Portugal1 site, 1 recruiting
- Recruiting
Unidade Local de Saúde de Santo António - Hospital de Santo António
Porto, Porto District, 4099-001
About this study
Official title: An Adaptive, 2-Part, Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Efficacy and Safety of IKT-001 in Pulmonary Arterial Hypertension (PAH)
This is an adaptive, 2-part, randomized, multicenter, double-blind, placebo-controlled, parallel-group study designed to evaluate the efficacy and safety of IKT-001 in adult participants with WHO Group 1 PAH.
- Conditions
- Pulmonary Arterial Hypertension
- Being tested
- IKT-001, Placebo
- Medical subject headings
- Pulmonary Arterial Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
IKT-001Drug
IKT-001 tablets for PO administration
PlaceboDrug
Placebo to IKT-001 tablets for PO administration
| Study group | Role | What they receive |
|---|---|---|
| IKT-001 | Experimental | IKT-001 tablets for PO administration Receives: Drug: IKT-001 |
| Placebo | Placebo comparator | Matching placebo to IKT-001 tablets for PO administration Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
[Part A] To evaluate the effect on Pulmonary Vascular Resistance (PVR) in participants with WHO Group 1 PAH treated with IKT-001 compared to placebo
Change in Pulmonary Vascular Resistance (PVR)
Measured: Baseline to Week 24
[Part B] To characterize the effects of IKT-001 on symptoms and characteristics of Pulmonary Arterial Hypertension compared to placebo
Change in 6-minute walk distance (6MWD)
Measured: Baseline to Week 24
Secondary outcomes (2)
To characterize the effects of IKT-001 on WHO Functional Class
Change in WHO Functional Class
Measured: Baseline up to Week 48
To characterize the effects of IKT-001 on time to clinical worsening
Time to clinical worsening
Measured: Baseline up to Week 48
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jan 2026
- Study start23 Apr 2026
- Primary completionJun 2029 (estimated)
- Study completionDec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pulmonary Arterial HypertensionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Adaptive, 2-part, randomized, multicenter, double-blind, placebo-controlled, parallel-group study
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 486 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Inhibikase Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07365332
- Sponsor's protocol ID
- IKT-001-201
- Acronym
- IMPROVE-PAH
- Status last verified
- May 2026
- First submitted
- 22 Jan 2026
- Last updated
- 2 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Adaptive, 2-Part, Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Efficacy and Safety of IKT-001 in Pulmonary Arterial Hypertension (PAH)
- ClinicalTrials.gov ID
- NCT07365332
- Acronym / sponsor ID
- IMPROVE-PAH / IKT-001-201
- Conditions
- Pulmonary Arterial Hypertension
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 486 participants (estimated)
- Lead sponsor
- Inhibikase TherapeuticsIndustry (pharma, biotech, devices)
- Study start
- 23 Apr 2026 (actual)
- Primary completion
- Jun 2029 (estimated)
- Study completion
- Dec 2029 (estimated)
- First posted
- 26 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is an adaptive, 2-part, randomized, multicenter, double-blind, placebo-controlled, parallel-group study designed to evaluate the efficacy and safety of IKT-001 in adult participants with WHO Group 1 PAH.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Adaptive, 2-part, randomized, multicenter, double-blind, placebo-controlled, parallel-group study
| Arm | Type | Receives |
|---|---|---|
| IKT-001 | Experimental | Drug: IKT-001IKT-001 tablets for PO administration |
| Placebo | Placebo comparator | Drug: PlaceboMatching placebo to IKT-001 tablets for PO administration |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (11 listed)
- Documented diagnosis of WHO PAH Group 1 in any of the following subtypes:
- Men and women 18 and 75 years of age (inclusive)
- Must have a body mass index (BMI) of ≥18.5 kg/m^2 and ≤35.0 kg/m^2 at screening.
- Baseline RHC performed during the Screening Period documenting a PVR of ≥ 400 dyn/sec/cm^5 ; pulmonary capillary wedge pressure (PCWP) ≤15 mmHg and mean pulmonary artery pressure (mPAP) >20 mmHg. PVR enrichment criteria to ensure population baseline PVR >700 dynes/sec/cm^5
- On stable doses of background PAH therapy including endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostacyclins, and soluble guanylate cyclase stimulators for ≥90 days prior to screening. Current use of sotatercept is not permitted.
Key exclusion criteria (31 listed)
- Diagnosis of PAH WHO Groups 2, 3, 4, or 5.
- Diagnosis of the following PAH Group 1 subtypes: human immunodeficiency virus (HIV)-associated PAH, PAH associated with portal hypertension, schistosomiasis-associated PAH, and pulmonary veno-occlusive disease.
- Any of the following blood pressure-related values or abnormalities: Uncontrolled systemic hypertension as evidenced by sitting systolic BP >160 mmHg or sitting diastolic BP >100 mmHg at screening, Baseline systolic BP <90 mmHg at screening, Syncope within 3 months prior to screening
- History of restrictive, constrictive, or congestive cardiomyopathy.
- ECG with Fridericia's corrected QT interval (QTcF) ≥ 450 msec in males or ≥ 470 msec in females at screening or ≥500 msec in the presence of a right bundle branch block.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| IKT-001IKT-001 tablets for PO administration | Drug | IKT-001 |
| PlaceboPlacebo to IKT-001 tablets for PO administration | Drug | Placebo |
Primary outcome
[Part A] To evaluate the effect on Pulmonary Vascular Resistance (PVR) in participants with WHO Group 1 PAH treated with IKT-001 compared to placebo
Time frame: Baseline to Week 24
Change in Pulmonary Vascular Resistance (PVR)
[Part B] To characterize the effects of IKT-001 on symptoms and characteristics of Pulmonary Arterial Hypertension compared to placebo
Time frame: Baseline to Week 24
Change in 6-minute walk distance (6MWD)
2 secondary outcomes
To characterize the effects of IKT-001 on WHO Functional Class
Time frame: Baseline up to Week 48
To characterize the effects of IKT-001 on time to clinical worsening
Time frame: Baseline up to Week 48
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2026.
- Individual participant dataSharing planned: No
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A Pilot Study of Microbiota Transplant With Antibiotic Preconditioning and Fiber Supplementation in Pulmonary Arterial Hypertension (GUT RESTORE-PAH)
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
43 sites in 14 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing IKT-001 in people with Pulmonary Arterial Hypertension, run by Inhibikase Therapeutics at 43 sites in 14 countries.
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 11 inclusion and 31 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: looking for participants now, as of the sponsor's last update on 2 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 43 sites in United States, Spain, New Zealand, United Kingdom, France and 9 more countries. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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?
Contact Medical Director, Inhibikase Therapeutics (1-302-295-3800, info@inhibikase.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
[Part A] To evaluate the effect on Pulmonary Vascular Resistance (PVR) in participants with WHO Group 1 PAH treated with IKT-001 compared to placebo (time frame: Baseline to Week 24). 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?
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 2 Sep 2026; AzTrials last refreshed its copy on 8 Nov 2026.