Phase 2 Study of REGN13335 in Adult Participants with Pulmonary Arterial Hypertension (PAH)

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Regeneron Pharmaceuticals Inc.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Cardiovascular Diseases [C14]

Trial duration

6 May 2026 → ongoing

Decision date (initial)

2026-03-18

Transition trial

No

Low-intervention

No

Rare-disease indication

Yes

Vulnerable population

No

Funding sources

Regeneron Pharmaceuticals

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Safety, Pharmacodynamic, Efficacy, Pharmacokinetic

To evaluate the effect of REGN13335 on pulmonary vascular resistance (PVR)

Secondary objectives 6

1. To evaluate the safety and tolerability of REGN13335
2. To evaluate the effect of REGN13335 on N-terminal pro-B-type natriuretic peptide (NT-proBNP), a biomarker of right ventricular dysfunction
3. To evaluate the effect of REGN13335 on hemodynamics
4. To evaluate the effect of REGN13335 on exercise capacity
5. To describe drug concentration following administration of REGN13335 in participants with PAH
6. To evaluate the effect of REGN13335 on soluble target concentrations

Conditions and MedDRA coding

Pulmonary Arterial Hypertension (PAH)

Regulatory references

Scientific advice from competent authorities

Federal Agency For Medicines And Health Products

Plan to share IPD

Yes

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 6

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
6. Note: Other protocol-defined inclusion criteria apply

Exclusion criteria 10

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
10. Note: Other protocol-defined exclusion criteria apply

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Change from baseline in Pulmonary Vascular Resistance (PVR)

Secondary endpoints 10

1. Occurrence of Treatment-Emergent Adverse Events (TEAEs)
2. Severity of TEAEs
3. Change from baseline in circulating N-Terminal pro-B-type Natriuretic Peptide (NT-proBNP) concentrations
4. Change from baseline in mean pulmonary artery pressure
5. Change from baseline in cardiac output
6. Change from baseline in cardiac index
7. Change from baseline in right atrial pressure
8. Change from baseline in 6-Minute Walk Distance (6MWD)
9. Concentrations of functional REGN13335 in plasma
10. Concentrations of total soluble Platelet-Derived Growth Factor-B (PDGF-B) ligands in plasma

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 2

Placebo 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Regeneron Pharmaceuticals Inc.

Sponsor organisation

Regeneron Pharmaceuticals Inc.

Address

777 Old Saw Mill River Road

City

Tarrytown

Postcode

10591-6717

Country

United States

Scientific contact point

Organisation

Regeneron Pharmaceuticals Inc.

Contact name

Medical Affairs

Public contact point

Organisation

Regeneron Pharmaceuticals Inc.

Contact name

Medical Affairs

Third parties 14

Locations

7 EU/EEA countries · 30 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 80 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

3 submissions — initial application plus substantial / non-substantial modifications