Combination therapy for pulmonary hypertension using racecadotril

ISRCTN ISRCTN96717546
DOI https://doi.org/10.1186/ISRCTN96717546
EudraCT/CTIS number 2012-003921-13
Secondary identifying numbers 14534
Submission date
28/06/2013
Registration date
28/06/2013
Last edited
11/09/2019
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
This study aims to measure the safety and effectiveness of racecadotril in patients with pulmonary hypertension taking the drug sildenafil. In this disease, the pressure of blood in the arterial system (network of channels that carry blood from the heart to the organs) of the lungs is increased due to the narrowing of the blood vessels in the lungs. In time it leads to heart failure, symptoms of shortness of breath and ultimately premature death. New treatments that reverse the excessive constriction seen in the blood vessels of the lung are needed. The study will investigate the effect of a drug (racecadotril) that has not been used in pulmonary hypertension before and its effect in addition to patients’ current medication sildenafil (otherwise known as Revatio) will also be studied. Racecadotril may relax blood vessels in the lungs. It stops a particular enzyme (enzymes are complex proteins that cause a specific chemical change in all parts of the body) from working and by doing this has been shown to reduce blood pressure in the lungs of animals. Racecadotril is already a licensed medicine in over 30 countries, including the UK, for patients with diarrhoea. It is widely available, with a reassuring safety record. Though there are no data describing its use in patients with pulmonary hypertension, it is not contra-indicated in patients with cardiovascular disease. The aim of this study, therefore, is to treat patients suffering with pulmonary hypertension with this combination of medicines to measure accurately if this therapy might improve future treatment of this disease. The study is split into two steps, step one is further split into steps 1a and 1b, which will recruit 12 patients (6 in each step). Step 2 will recruit 12 patients.

Who can participate?
Step 1: Patients currently taking sildenafil, who have not experienced any complications with their treatment, and are scheduled for routine right heart catheterisation
Step 2: Patients who are currently taking sildenafil for pulmonary hypertension and have not experienced any complications with their treatment
Patients can enter either or both steps

What does the study involve?
Patients who take part receive either the active treatment capsule(s) or a placebo (dummy) which looks the same but does not contain active ingredients. Each step involves 12 patients, 8 on racecadotril and 4 on the dummy pill. Each patient is put into a treatment group by chance using a computer programme. The trial is ‘double blind’ so neither the patient nor their doctor know which treatment group the patient is in but this can be found out, if necessary. There are a number of screening tests for each step; all screening results must be acceptable for study entry. Step 1: a review of medical history; a physical examination; a walking test for 6 minutes; blood sample for routine testing; routine care right heart catheterisation procedure results. Step 2: Same screening tests as step 1 excluding the right heart catheterisation.
Step 1: The procedures in this step take place in hospital over 1 day. As part of routine care each patient has a procedure called a right heart catheterisation involving the insertion of a tube into a blood vessel in the leg and a wire inserted through the tube and into the heart. The patient then takes 1 or 2 capsules of the study drug. The right heart catheterisation procedure is extended for the study by about 2 hours to enable the measurement of changes in blood flow and blood pressure in the lungs after taking the trial drug.
Each patient has 5 sets of blood samples taken over a period of up to 6 hours 15 minutes; usually these samples are collected via another tube, inserted once (e.g. in the arm) that remains in place until the end of the blood sampling period. Blood flow and pressure in the patient’s lungs and other areas are monitored, as are emerging side effects.
Step 2: The procedures in this step last for 12 - 14 days. The first and last day of this step takes place in hospital but the patients take the treatment at home. The patient has a walking test for 6 minutes, a blood sample and heart rate and blood pressure taken just before the drug is taken. Each patient takes 1 or 2 capsules, 3 times a day for about 14 days. A nurse calls each patient on the 7th day of treatment to discuss any side effects. After about 14 days, patients return to hospital for a blood sample, a 6-minute walking test, heart rate and blood pressure measurements and a side effects assessment.

What are the possible benefits and risks of participating?
There is no benefit to the patient as a participant in the study but patients may be helping to improve treatment for future patients with pulmonary hypertension. Following consideration of the results it will be known if racecadotril, used in combination with sildenafil, has potential to improve pulmonary hypertension treatment. Racecadotril has not been used in combination with sildenafil before and, although there are no known interactions between the two drugs, there could be some side effects which have not been seen. Racecadotril is licenced for use in the UK, and many other countries for patients with diarrhoea. Racecadotril is not licensed for the treatment of pulmonary hypertension. It has been taken in higher doses than we plan to use in this study without any problems and is not known to interact with other drugs.

Where is the study run from?
This study is being managed by the University College London Clinical Trials Unit. University College London (UCL) is the study sponsor, the organisation legally responsible for the study. Patient care will be carried out by staff at the Royal Free Hospital, London.

When is the study starting and how long is it expected to run for?
August 2013 to August 2015

Who is funding the study?
1. The British Heart Foundation (UK)
2. The Biomedical Research Centre (UCL Hospitals/UCL) (UK)
3. The Clinical Research Development Committee (UCL Hospitals/UCL) (UK)

Who is the main contact?
CCTU Enquiry Desk, Comprehensive Clinical Trials Unit at UCL
CCTU-enquiries@ucl.ac.uk
(updated 03/09/2019, previously: 1. Harriet Quartly, h.quartly@ucl.ac.uk; 2. Michelle Tetlow, comparetrial@ucl.ac.uk)

Contact information

Dr CCTU Enquiry Desk
Scientific

Comprehensive Clinical Trials Unit at UCL
Institute of Clinical Trials and Methodology
90 High Holborn
London
WC1V 6LJ
United Kingdom

Phone +44 (0) 20 7907 4669
Email CCTU-enquiries@ucl.ac.uk

Study information

Study designRandomised interventional treatment trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details to request a patient information sheets
Scientific titleCOMbination therapy for PulmonAry hypertension using RacEcadotril (COMPARE): a randomised trial
Study acronymCOMPARE
Study objectivesThis trial aims to measure the efficacy and safety of racecadotril in patients with pulmonary hypertension taking sildenafil. In this disease, the pressure of blood in the arterial system of the lungs is increased. In time it leads to heart failure, symptoms of shortness of breath and ultimately premature death. New treatments that reverse the excessive constriction seen in the blood vessels of the lung are needed.

Racecadotril has a novel mechanism of action that we hypothesise will relax blood vessels in the lungs. It inhibits the enzyme neutral endopeptidase and by this mechanism has been shown to reduce pulmonary blood pressure in animal models. Racecadotril is already an existing licensed medicine in 30 European countries (including the UK), Asia and South America for patients with diarrhoea. Inhibition of neutral endopeptidase in the intestine by racecadotril reduces the extent of infectious diarrhoea. Indeed, racecadotril has had an established role in the treatment of patients with infectious diarrhoea since its launch in 1993. It is now widely available as a generic drug, has a reassuring safety record (>1 million adult exposures).

Though there are no data describing its use in patients with pulmonary hypertension, it is not contra-indicated in patients with cardiovascular disease. This trial will explore the pharmacology of racecadotril for the first time in patients with pulmonary hypertension taking sildenafil and in this regard, the drug will be used outside its licensed indication.

The aim of this project, therefore, is to treat patients suffering with pulmonary hypertension with this new combination of medicines to measure accurately if this therapy might improve treatment of this disease.
Ethics approval(s)London-Westminster, First MREC approval date 07/06/2013, ref: 13/LO/0387
Health condition(s) or problem(s) studiedTopic: Cardiovascular, Respiratory; Subtopic: Cardiovascular (all Subtopics), Respiratory (all Subtopics); Disease: Respiratory, Congenital Heart Disease and Pulmonary Hypertension
InterventionRacecadotril and Placebo capsule(s). Placebo is matched in appearance to active.

Step 1a: 1 racecadotril 100mg capsule OR 1 placebo capsule administered once
Step 1b: 1 or 2 racecadotri 100mg capsules OR 1 or 2 placebo capsules (depending on Independent Data Monitoring review, administered once)
Step 2: 1 or 2 racecadotril 100mg capsules OR 1 or 2 placebo capsules (depending on Independent Data Monitoring review, administered 3 x a day for 12 -14 days)

Study Entry : Randomisation –patients may be randomised more than once if they consent to both steps
Intervention typeOther
Primary outcome measureThe maximum percentage change from baseline in plasma atrial natriuretic peptide (ANP) concentration; Timepoint(s): Step 1: Day 0 baseline & 1, 2, 3 and 6 hours post IMP
Step 2: Day 0 baseline & at 12-14 days of IMP
Secondary outcome measuresStep 1:
1. Additional biomarkers in the blood; timepoints: Day 0 baseline & at 1,2,3 & 6 hours post IMP
2. Pulmonary haemodynamic assessments; timepoints: Day 0 baseline and post IMP at 1.5 hours and 2 hours
3. Systemic haemodynamic assessments; timepoints: Day 0 baseline and over 6 hours, at half hourly intervals post IMP
4. Safety assessment; timepoints: Day 0 baseline and over 6 hours, at half hour post IMP

Step 2:
1. 6 minute walk test; timepoints: Day 0 baseline and at 12-14 days post treatment with IMP.
2. Additional biomarkers in the blood; timepoints: Day 0 baseline and at 12-14 days post treatment with IMP
3. Systemic haemodynamic assessments; timepoints: Day 0 baseline and at 12-14 days post treatment with IMP.
4. Safety assessment timepoints: At 7 days of IMP treatment and at 12-14 days post treatment with IMP
Overall study start date01/08/2013
Completion date05/04/2017

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
Upper age limit80 Years
SexBoth
Target number of participantsPlanned Sample Size: 24; UK Sample Size: 24; Description: Patients will be randomised 2:1, active:placebo
Total final enrolment21
Key inclusion criteria1. WHO Group I pulmonary hypertension (i.e. idiopathic, familial or associated with connective tissue diseases
2. 18-80 years old
3. Technically satisfactory routine right heart catheterisation (Step 1 only)*
4. On sildenafil (20-100 mg; t.i.d.)
5. Six minute walk distance of >150 m
6. No changes to PH specific therapies for 1 month
7. Not pregnant (women only). Women of child-bearing potential must have a negative pregnancy test within seven days prior to randomisation they must be willing to use an effective method of contraception (including hormonal or barrier method of birth control) from the time consent is signed until six weeks after treatment discontinuation.
8. Able to provide consent for the trial
* Technically satisfactory means that the PI or delegated physician is content that the patient is able to have the catheter in for longer and that the necessary trial information is able to be extracted.
9. Target Gender: Male & Female
Key exclusion criteria1. Known sensitivity to racecadotril or its excipients
2. Clinical diagnosis of liver cirrhosis or ALT/AST >2 X ULN
3. Kidney disease with an eGFR of <50 ml/min
4. History of angioedema
5. Systolic blood pressure <85 mmHg
6. Known history of drug or alcohol abuse within six months of enrolment
7. Participation in a clinical study involving another investigational drug
8. Women who are breastfeeding
9. Patients taking ACE inhibitors
10.Any clinical condition for which the investigator would consider the patient unsuitable for the trial
Date of first enrolment12/02/2014
Date of final enrolment11/10/2016

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

University College London
London
WC1E 6BT
United Kingdom

Sponsor information

University College London (UK)
University/education

Gower Street
London
WC1E 6BT
England
United Kingdom

Email CCTU-enquiries@ucl.ac.uk
Website http://www.ucl.ac.uk/
ROR logo "ROR" https://ror.org/02jx3x895

Funders

Funder type

Charity

British Heart Foundation (BHF) (UK) Grant Codes: PG/11/88/28992
Private sector organisation / Trusts, charities, foundations (both public and private)
Alternative name(s)
the_bhf, The British Heart Foundation, BHF
Location
United Kingdom
NIHR Biomedical Research Centre (BRC) (UK)

No information available

University College London Hospitals NHS Foundation Trust
Private sector organisation / Universities (academic only)
Alternative name(s)
University College London Hospitals, UCLH
Location
United Kingdom

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planParticipants were able to find out their treatment allocation and the results of the study (including access to the journal publication) by contacting the site research team. A summary of the final study results was produced for participants should they have requested/ request this.

(updated 11/09/2019, previously: Not provided at time of registration)
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Basic results 03/09/2019 No No
Results article results 01/05/2019 03/09/2019 Yes No
HRA research summary 28/06/2023 No No

Editorial Notes

11/09/2019: The publication and dissemination plan was update
03/09/2019: The following changes were made to the trial record:
1. Added clinical trials register.eu link to basic results (scientific)
2. The total final enrolment was added
3. The scientific contact was changed from Mrs Harriet Quartly <h.quartly@ucl.ac.uk> to CCTU Enquiry Desk, Comprehensive Clinical Trials Unit at UCL, CCTU-enquiries@ucl.ac.uk
4. The overall end date was changed from 03/08/2015 to 05/04/2017.
5. The recruitment start date was changed from 01/08/2013 to 12/02/2014.
6. The recruitment end date was changed from 03/08/2015 to 11/10/2016.
7. The sponsor's email address was changed from comparetrial@ucl.ac.uk to CCTU-enquiries@ucl.ac.uk.
8. Publication reference added.
9. The plain English summary was updated to reflect these changes.
14/09/2017: No publications found, verifying study status with principal investigator.