Study of REGN13335 in Adult Participants With Pulmonary Arterial Hypertension (PAH)
A Phase 2, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamic Effects of REGN13335, an Anti-PDGF-B Monoclonal Antibody, in Adults With Pulmonary Arterial Hypertension
- Pulmonary Arterial Hypertension (PAH)
At a glance
- Phase
- Phase 2
- Study type
- Interventional
- Sponsor
- Regeneron Pharmaceuticals
- Enrolment target
- 99
- Started
- 6 May 2026
- Main results due
- 27 February 2028
- Study sites
- 32
- Registry updated
- 25 September 2026
Can you take part?
- Aged 18 years and over.
- Open to any sex.
- You need the condition being studied — healthy volunteers are not accepted.
These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.
Read the full eligibility criteria
Key Inclusion Criteria: 1. Documented clinical diagnosis of PAH (Group 1 PH according to the 7th World Symposium on Pulmonary Hypertension (WSPH)) 2. WHO functional class II or III (slight to marked limitation of functional status due to PAH) 3. Receiving background Standard Of Care (SOC) therapy for PAH on a stable dose and regimen, as determined by the investigator, as described in the protocol 4. PVR ≥400 dynes∙sec/cm\^5 (5 Wood units) based on Right Heart Catheterization (RHC) during the screening period 5. Has 6MWD ≥150 and ≤550 meters repeated twice during screening as described in the protocol Key Exclusion Criteria: 1. Has Group 2 (PH associated with left heart disease), Group 3 (PH associated with lung diseases and/or hypoxia), Group 4 (PH associated with pulmonary artery obstructions), or Group 5 (PH with unclear and/or multifactorial mechanisms) PH according to the 7th WSPH 2. Pulmonary Arterial Wedge Pressure (PAWP) \>15 mm Hg by RHC during the screening period 3. History of left-sided heart disease and/or clinically significant cardiac disease, as described in the protocol 4. Obstructive lung disease defined as Forced Expiratory Volume in 1 second (FEV1)/Forced Vital Capacity \<0.7 and FEV1 \<70% of the predicted value as described in the protocol 5. Evidence of interstitial lung disease as defined in the protocol 6. Evidence of chronic thromboembolic pulmonary disease or acute pulmonary embolism as described in the protocol 7. Participants requiring anticoagulation and/or antiplatelet therapy for an underlying medical condition as described in the protocol 8. Has any history of intracranial bleeding or any history of elevated intracranial pressure 9. Has any history of bleeding meeting criteria as described in the protocol Note: Other protocol-defined Inclusion/ Exclusion criteria apply
What this study is about
In the sponsor’s own words, from the registry.
This study is researching an experimental drug called REGN13335. The study is focused on participants with Pulmonary Arterial Hypertension (PAH). The aim of the study is to see how safe and effective REGN13335 is in participants with PAH who are taking other PAH medicines.
The study is looking at several other research questions, including:
* What side effects may happen from taking REGN13335 * How much REGN13335 is in the blood at different times * Whether the body makes antibodies against REGN13335 (which could make REGN13335 less effective or could lead to side effects)
Study sites(32)
University of Colorado Denver
Aurora, Colorado, United States
Recruiting
Tufts Medical Center
Boston, Massachusetts, United States
Recruiting
University of Nebraska Medical Center - 2365
Omaha, Nebraska, United States
Recruiting
University of Cincinnati
Cincinnati, Ohio, United States
Recruiting
The Prince Charles Hospital
Brisbane, Queensland, Australia
Recruiting
Mater Misericordiae Ltd
South Brisbane, Queensland, Australia
Recruiting
Royal Hobart Hospital
Hobart, Tasmania, Australia
Recruiting
UZ Leuven
Leuven, Vlaams-Brabant, Belgium
Recruiting
H.U.B. Erasme Hospital
Brussels, Belgium
Recruiting
Hopital Bicetre
Le Kremlin-Bicêtre, France
Recruiting
Nouvel hopital civil
Strasbourg, France
Recruiting
Universitatsklinikum Halle
Halle, Saxony-Anhalt, Germany
Recruiting
Clinic of University Greifswald
Greifswald, Germany
Recruiting
Universitatsmedizin Mainz
Mainz, Germany
Recruiting
P. Stradins Clinical University hospital
Riga, Latvia
Recruiting
University Clinical Hospital in Poznan - Early Phase Unit
Poznan, Greater Poland Voivodeship, Poland
Recruiting
University Hospital in Bialystok
Bialystok, Podlaskie Voivodeship, Poland
Recruiting
Oddzial Kardiologiczny
Lodz, Łódź Voivodeship, Poland
Recruiting
Gachon University Gil Medical Center
Namdong-gu, Incheon, South Korea
Recruiting
Asan Medical Center
Seoul, Songpa-gu, South Korea
Recruiting
Seoul National University Hospital
Seoul, South Korea
Recruiting
Severance Hospital
Seoul, South Korea
Recruiting
Samsung Medical Center
Seoul, South Korea
Recruiting
Hospital Vall d'Hebron
Barcelona, Catalonia, Spain
Recruiting
Hospital Universitario Costa del Sol
Marbella, Malaga, Spain
Recruiting
Hospital Clinic, Barcelona
Barcelona, Spain
Recruiting
University hospital 12 de octubre
Madrid, Spain
Recruiting
University Hospital Salamanca
Salamanca, Spain
Recruiting
Hospital Universitario De Toledo
Toledo, Spain
Recruiting
Royal United Hospitals Bath NHS Foundation Trust
Bath, United Kingdom
Recruiting
Royal Free Hospital
London, United Kingdom
Recruiting
Imperial College Healthcare NHS Trust, Hammersmith Hospital
London, United Kingdom
Recruiting
Showing 32 of 32 sites. 32 of the 32 sites on this study are recruiting right now — a site can stop enrolling while the study as a whole is still open.
Source: ClinicalTrials.gov record NCT07318597. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.
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