Skip to content

Effects of Riociguat on RIght VEntricular Size and Function in PAH and CTEPH

An Open-label, Prospective, Single Centre Study of the Effects of Riociguat on RIght VEntricular Size and Function in Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension

Status
Terminated
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04954742
Acronym
RIVERII
Enrollment
30
Registered
2021-07-08
Start date
2022-04-13
Completion date
2025-08-13
Last updated
2025-09-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Primary Pulmonary Arterial Hypertension, Chronic Thromboembolic Pulmonary Hypertension

Keywords

pulmonary arterial hypertension, Chronic Thromboembolic Pulmonary Hypertension, riociguat, right heart function

Brief summary

This is an open-label, single-armed, prospective single-centre clinical study to evaluate the effect of riociguat on right heart size and function in patients with manifest PAH and CTEPH.

Detailed description

Right heart size and function are of utmost prognostic importance in PAH/CTEPH. RV performance measured by echocardiography and enlarged RA area have been shown to be independent prognostic factors in PAH. Recently, a retrospective single centre study has shown that riociguat treatment was associated with a significant reduction of RV and RA area after 3, 6 and 12 months compared to baseline. RA area significantly decreased after 12 months and RV systolic function assessed with tricuspid annular plane systolic excursion (TAPSE) improved after 6 and 12 months of riociguat therapy. The results were confirmed by a recent retrospective multicentre study. It is therefore reasonable to assume a beneficial effect of riociguat on right heart size and function. The primary efficacy endpoint in this study is the change in RV and RA area from baseline to 24 weeks. Treatment will be initiated and individually adjusted according to systolic blood pressure and tolerability. Patients who discontinue medication prematurely will be asked to continue with study assessments and perform study visits as outlined in the protocol. Medical examinations comprise medical history, physical examination, electrocardiogram (ECG), blood gas analyses, lung function tests, laboratory testing (including NT-proBNP), echocardiography at rest, and right heart catheterization (RHC) according to clinical practice of the PH centre. The prospective period of data collection comprises a 24-week study period a follow-up phase of about 30±7 days. Outcome (survival and transplant-free survival) of all patients will be assessed when the last patient has terminated his/her 24-week observation period.

Interventions

Treatment will be initiated and individually adjusted according to systolic blood pressure and tolerability. During the titration phase, each patient will be asked to measure their peripheral systolic blood pressure and the heart rate at home three times per day and document the values in the patient diary. The results will be examined by the investigator during each visit/phone call-visit. Provided that the systolic blood pressure is ≥ 95 mmHg measured at trough before intake of each dose and the patient has no signs or symptoms of hypotension, the dose of study medication will be titrated by +0.5 mg tid every 2 weeks until maximal tolerated dosage (maximal permitted dose: of 2.5 mg tid). After the titration period, blood pressure should be measured upon signs or symptoms of hypotension. Maintenance dose: The established individual dose should be maintained unless signs and symptoms of hypotension occur.

Sponsors

Merck Sharp & Dohme LLC
CollaboratorINDUSTRY
Heidelberg University
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. ≥18 years of age at time of inclusion. 2. Male and female patients with symptomatic PAH with a mean pulmonary artery pressure (mPAP) \>20 mmHg and pulmonary vascular resistance (PVR) ≥2 Wood Units (WU), pulmonary arterial wedge pressure (PAWP) ≤15 mmHg (Group I / Nice Clinical Classification of Pulmonary Hypertension) or CTEPH (Group IV / Nice Clinical Classification of Pulmonary Hypertension) defined as inoperable measured at least 3 months after start of full anticoagulation and mPAP \>20 mmHg and PVR ≥2 WU, PAWP ≤15 mmHg; or with persisting or recurrent PH after pulmonary endarterectomy (mPAP \>20 mmHg and PVR ≥2 WU, PAWP ≤15 mmHg measured at least 6 months after surgery (acc. to Simonneau et al. 2018). 3. Treatment naïve patients (with respect to PAH specific medication) and patients pre-treated with an endothelin receptor antagonist or a prostacyclin analogue, pre-treated for 2 months before screening at most (according to upfront combination treatment).\* 4. \*Pre-treated patients need to be stable on endothelin receptor antagonists or prostacyclin treatment for at least two weeks prior to Visit 1. Stable is defined as no change in the type of endothelin receptor antagonists or prostacyclin analogue and the respective daily dose. 5. A patient may also be enrolled, if a persisting phosphodiesterase type 5 (PDE-5) inhibitor treatment (pre-treated for 2 months before screening at most) with or without combination treatment with an endothelin receptor antagonist or prostacyclin analogue is to be switched to riociguat by clinical indication, particularly when the patient´s risk-profile remained in intermediate risk group despite adequate initial treatment including PDE5i (defined as at least 3 of the following parameters: clinical signs of progression, persistent WHO-FC III, 6MWD between 165-440m, peak V02 11-15ml/min/kg (35-65% predicted), NTproBNP 300-1400 ng/l, RA-area 18-26cm2,RAP 8-14mmHg, CI 2,0-2,4 l/min) or in case of PDE5i intolerance. Any decision to switch will be made by the clinicians at a regular clinical follow-up visit. 6. Unspecific treatments which may also be used for the treatment of PH such as oral anticoagulants, diuretics, digitalis, calcium channel blockers or oxygen supplementation are permitted. However, treatment with anticoagulants (if indicated) must have been started at least 1 month before visit in patients with PAH 1. 7. RHC results must not be older than 6 months at screening (will be considered as baseline values) and must have been measured in the participating centre under standardized conditions (refer to the study specific Swan Ganz catheterization manual). If the respective measurements have not been performed in context with the patient's regular diagnostic workup, they have to be performed as a part of the study during the pre-study phase (after the patient signed the informed consent). 8. Women without childbearing potential defined as postmenopausal women aged 50 years or older, women with bilateral tubal ligation, women with bilateral ovariectomy, and women with hysterectomy can be included in the study. 9. Women of childbearing potential can only be included in the study if all of the following applies (listed below): a. Negative serum pregnancy test at Screening and a negative urine pregnancy test at study start (visit 1). b. Agreement to undertake monthly urine pregnancy tests during the study and up to at least 30 days after study treatment discontinuation. These tests should be performed by the patient at home. c. Agreement to follow the contraception scheme as specified from Screening until at least 30 days after study treatment discontinuation. 10. Patients who are able to understand and follow instructions and who are able to participate in the study for the entire period. 11. Patients must have given their written informed consent to participate in the study after having received adequate previous information and prior to any study-specific procedures.

Exclusion criteria

1. Pregnant women, or breast-feeding women, or women of childbearing potential not able or willing to comply with study-mandated contraception methods specified above. 2. Patients with PH specific treatment \<2 months before screening. 3. Patients with a medical disorder, condition, or history of such that would impair the patient's ability to participate or complete this study in the opinion of the investigator. 4. Patients with underlying medical disorders with an anticipated life expectancy below 2 years (e.g. active cancer disease with localized and/or metastasized tumour mass). 5. Patients with a history of severe or multiple drug allergies 6. Patients with hypersensitivity to the investigational drug or any of the excipients. 7. Patients unable to perform a valid 6MWD test (e.g. orthopaedic disease, peripheral artery occlusive disease, which affects the patient´s ability to walk). 8. The following specific medications for concomitant treatment of PH or medications which may exert a pharmacodynamic interaction with the study drug are not allowed: 1. Parenteral prostacyclin analogues 2. Specific phosphodiesterase inhibitors (e.g. sildenafil or tadalafil): may be switched to riociguat but not be given in addition to the study drug 3. or unspecific phosphodiesterase inhibitors (e.g. dipyridamole, theophylline) 4. NO donors (e.g. Nitrates) 9. Pulmonary diseases exclusions 1. Moderate to severe bronchial asthma or COPD (Forced Expiratory Volume \<60% predicted) or severe restrictive lung disease (Total Lung Capacity \< 70% predicted) and/or defined as if high resolution computed tomography shows \<20% parenchymal lung disease. 2. Severe congenital abnormalities of the lungs, thorax, and diaphragm. 3. Clinical or radiological evidence of Pulmonary-Veno-Occlusive Disease (PVOD) or Pulmonary Capillary Haemangiomatosis (PCH) or PH and idiopathic interstitial pneumonia (PH-IIP) 10. Cardiovascular exclusions: 1. Uncontrolled arterial hypertension (systolic blood pressure \>180 mmHg and /or diastolic blood pressure \>110 mmHg). 2. Systolic blood pressure \<95 mmHg. 3. Left heart failure with an ejection fraction less than 40%. 4. Pulmonary venous hypertension with pulmonary arterial wedge pressure \>15 mmHg. 5. Hypertrophic obstructive cardiomyopathy. 6. Severe proven or suspected coronary artery disease according to investigators opinion (patients with Canadian Cardiovascular Society Angina Classification class 2-4, and/or requiring nitrates, and/or myocardial infarction within the last 3 months before Visit 1). 7. Clinical evidence of symptomatic atherosclerotic disease (e.g. peripheral artery disease with reduced walking distance, history of stroke with persistent neurological deficit etc). 11. Exclusions related to disorders in organ function: a) Clinically relevant hepatic dysfunction indicated by: i. bilirubin \>2 times upper limit normal ii. and / or hepatic transaminases \>3 times upper limit normal iii. and / or signs of severe hepatic insufficiency (e.g. impaired albumin synthesis with an albumin \< 32 g/l, hepatic encephalopathy \> grade 1a: West Haven Criteria of Altered Mental Status In Hepatic Encephalopathy) b) Renal insufficiency (glomerular filtration rate \<30 ml/min e.g. calculated based on the Cockcroft formula).

Design outcomes

Primary

MeasureTime frameDescription
Change in RV (right ventricular) areaBaseline to 24 weeksechocardiographic analysis right atrial (RA) area, measured by echocardiography.
Change in RA (right atrial) areaBaseline to 24 weeksechocardiographic analysis

Secondary

MeasureTime frameDescription
AST changesbaseline to 12 weeksChange in liver enzymes
ALT changesbaseline to 12 weeksChange in liver enzymes
Bilirubin changesbaseline to 12 weeksChange in liver enzymes
CRP changesbaseline to 12 weeksChange in laboratory parameters
sodium changesbaseline to 12 weeksChange in laboratory parameters
Urea changesbaseline to 12 weeksChange in renal parameters
creatinine changesbaseline to 12 weeksChange in renal parameters
creatinine clearance changesbaseline to 12 weeksChange in renal parameters
Change in RV Areabaseline to 12 weeksechocardiographic analysis
Change in RA Areabaseline to 12 weeksechocardiographic analysis
Change in systolic pulmonary artery pressure (sPAP)baseline to 12 weeksechocardiographic analysis
Change in RV fractional area change (FAC)baseline to 24 weeksechocardiographic analysis
Change in Peak velocity of tricuspid regurgitation (TRV)baseline to 12 weeksechocardiographic analysis
Change in inferior vena cava (IVC) diameter and IVC collapsebaseline to 24 weeksechocardiographic analysis
Change in Right Ventricle Outflow Tract Velocity Time Integral (RVOT VTI)baseline to 12 weeksechocardiographic analysis
Change in Eccentricity index (EI)baseline to 24 weeksechocardiographic analysis
Change in Tricuspid Annular Plane Systolic Excursion (TAPSE)baseline to 12 weeksechocardiographic analysis
Change in Right ventricular pump function (qualitative)baseline to 24 weeksechocardiographic analysis
Change in left ventricular pump function (qualitative)baseline to 24 weeksechocardiographic analysis
Change in Left Atrial (LA) diameterbaseline to 12 weeksechocardiographic analysis
Change in LV diastolic functionbaseline to 24 weeksechocardiographic Analysis measured as: (LV transmitral E wave and A wave, E' wave of interventricular septum and lateral wall pulsed tissue Doppler, isovolumic relaxation time, mitral deceleration time)
Change in Diameters of pulmonary arterybaseline to 12 weeksechocardiographic Analysis
Change in cardiac indexbaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in cardiac outputbaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in sPAPbaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in dPAPbaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in mPAPbaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in PAWPbaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in right atrial pressure (RAP)baseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in PVRbaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in Central venous saturation from pulmonary arterybaseline and after 24 weeksPulmonary hemodynamics by right heart catheterization
Change in 6-minute walking distancebaseline to 12 weeksChange in exercise capacity
forced vital capacity (FVC)baseline to 12 weeksChange in Lung function Tests
Change in forced expiratory volume in one second (FEV1)baseline to 12 weeksChange in Lung function Tests
Change in FEV1% of maximal vital capacity (VC max)baseline to 12 weeksChange in Lung function Tests
Change in total lung capacity (TLC)baseline to 12 weeksChange in Lung function Tests
Change in residual volumebaseline to 12 weeksChange in Lung function Tests
Change in diffusion-limited carbon monoxide (DLCO)baseline to 24 weeksChange in Lung function Tests
Change in DLCO/VA (Krogh) factorbaseline to 12 weeksChange in Lung function Tests
Change in partial pressure of oxygenbaseline to 12 weeksChange in capillary or arterial blood gas analysis
Change in partial pressure of carbon dioxidebaseline to 12 weeksChange in capillary or arterial blood gas analysis
Change in SaO2baseline to 12 weeksChange in capillary or arterial blood gas analysis
Change in pHbaseline to 24 weeksChange in capillary or arterial blood gas analysis
Change in Blood pressurebaseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in heart ratebaseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in workloadbaseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in oxygen consumption as total and per kg body weightbaseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in exhaled carbon dioxide (VCO2)baseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in oxygen saturationbaseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in oxygen pulsebaseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in minute ventilationbaseline to 12 weeksChange in Cardiopulmonary exercise testing
haemoglobin changesbaseline to 12 weeksChange in laboratory parameters
Change in respiratory equivalents for carbon dioxidebaseline to 12 weeksChange in Cardiopulmonary exercise testing
Change in respiratory reservebaseline to 12 weeksChange in Cardiopulmonary exercise testing
WHO FCbaseline to 12 weeksChange in WHO functional class
SF-36baseline to 24 weeksChange in Quality of life parameters by questionnaire SF-36
NT-proBNPbaseline to 12 weeksChange in laboratory parameters
Change in respiratory equivalents for oxygenbaseline to 12 weeksChange in Cardiopulmonary exercise testing
haematocrit changesbaseline to 12 weeksChange in laboratory parameters

Countries

Germany

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026