Plain English Summary
Background and study aims
Haemophilia A is an inherited clotting disorder primarily affecting males. It is caused by having a low level of a clotting factor called factor VIII (FVIII). Haemophilia B is also caused by low levels of a clotting factor and this is caused by having a reduction in factor IX (FIX). Haemophilia (both A and B) increases the risk of bleeding, particularly in the joints and muscles. Patients with factor levels of <1% are defined as having severe haemophilia, patients with levels between 1-4% are said to suffer from moderate disease and patients with levels of 5% or greater are said to suffer from mild Haemophilia defined as mild disease. Patients with severe haemophilia are at greatest risk of spontaneous bleeds (bleeding for no reason) and require regular treatment with intravenous infusions of clotting factors to prevent bleeding. At the moment monitoring of treatment and predicting the likely risk of bleeding for patients with haemophilia is determined using a standard clotting test, where the factor VIII or factor IX is measured. But not all patients with similar clotting factor levels (both baseline levels and post-treatment levels) have the same tendency for bleeding. Newer clotting tests: known as 'global haemostasis assays' may be better at telling doctors whether a patient will be more or less likely to bleed after treatment. These tests look at lots of different, interacting parts of the clotting system. This study will tests two global clotting tests: thrombin generation and a viscoelastic test called rotational thromboelastometry (ROTEM). These tests will be evaluated and compared to standard tests, both to see if these tests are accurate and also to see if they correlate better with patients' bleeding risks.
Who can participate?
Adult men (aged at least 18) diagnosed with haemophilia.
What does the study involve?
Participants are asked to provide one or two additional aliquots of blood (5.4 ml citrated blood) for this study whilst undergoing routine clinical assessment. No additional blood draws are requested over and above the samples that are taken at the time of the patients’ routine blood draws. All patients with haemophilia are routinely assessed at each clinic appointment by means of at least one blood sample; a ‘baseline’ blood sample is taken for testing either factor VIII or factor IX levels. Patients who require prophylactic treatment (regular infusions) routinely have two blood samples taken in clinic: a trough level and a post-infusion level. A trough sample is a blood test taken just before the next dose of clotting factor is required and gives an estimate of how much of the factor remains in a patient’s blood stream. The trough level can be used to guide ongoing therapy. The post-infusion level provides information about how much the factor level rises in the blood stream after an injection.
What are the possible benefits and risks of participating?
There are no risks and no immediate benefits from taking part in this study.
Where is the study run from?
Oxford Haemophilia & Thrombosis Centre (UK)
When is the study starting and how long is it expected to run for?
October 2015 to March 2016
Who is funding the study?
Blood Coagulation and Research Fund, Oxford Haemophilia and Thrombosis Centre (OHTC) (UK)
Who is the main contact?
Dr Nicola Curry
nicola.curry@ouh.nhs.uk
Trial website
Contact information
Type
Public
Primary contact
Dr Nicola Curry
ORCID ID
Contact details
Oxford Haemophilia & Thrombosis Centre
Oxford
OX3 7LE
United Kingdom
01865 225316
nicola.curry@ouh.nhs.uk
Type
Scientific
Additional contact
Dr Nicola Curry
ORCID ID
Contact details
Oxford Haemophilia & Thrombosis Centre
Oxford
OX3 7LE
United Kingdom
01865 225316
nicola.curry@ouh.nhs.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
1.0
Study information
Scientific title
Global haemostasis assays: their use in patients with haemophilia
Acronym
Study hypothesis
This is an observational study evaluating the utility of global haemostasis assays (i.e. thrombin generation (TGT) and thromboelastometry (ROTEM)) in assessing haemostatic ability in haemophilia patients. the primary objectives are to: find a normal range for TGT and ROTEM for both haemophilia and control subjects and to determine the reproducibility of these assays. Secondary objectives are: to correlate clinical outcomes in patients with haemophilia with TGT and ROTEM values and to compare these results with standard laboratory factor assay measurements.
Ethics approval
NRES Committee South Central - Oxford C, 15/07/2015, ref: 15/SC/0316
Study design
Single-centre observational study
Primary study design
Observational
Secondary study design
This is a laboratory study evaluating global assays of haemostasis
Trial setting
Hospitals
Trial type
Other
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet.
Condition
This study is evaluating newer global blood clotting tests and their use and reproducibility in patients with haemophilia A and haemophilia B.
Intervention
Participants will be asked to provide one or two additional aliquots of blood (5.4 ml citrated blood) for this study whilst undergoing routine clinical assessment. No additional blood draws will be requested over and above the samples that are taken at the time of the patients’ routine blood draws.
All patients with haemophilia are routinely assessed at each clinic appointment by means of at least one blood sample; a ‘baseline’ blood sample is taken for testing either factor VIII or factor IX levels.
Patients who require prophylactic treatment (regular infusions) routinely have two blood samples taken in clinic: a trough level and a post-infusion level. A trough sample is a blood test taken just before the next dose of clotting factor is required and gives an estimate of how much of the factor remains in a patient’s blood stream. The trough level can be used to guide ongoing therapy. The post-infusion level provides information about how much the factor level rises in the blood stream after an injection.
Intervention type
Other
Phase
Drug names
Primary outcome measures
The primary outcome is to find a normal range for thrombin generation and ROTEM measures in patients with haemophilia as measured by evaluating a blood sample at time 0 hours. The blood will be tested for thrombin generation and for whole blood viscoelastometric measures which are both global measures of coagulation.
Secondary outcome measures
Secondary outcome will be to correlate the laboratory tests with clinical outcome. Thrombin generation measures and ROTEM measures will be compared at time 0 hours and correlated with the number of joint bleeds that a patient has as measured using an annualised bleeding rate.
Overall trial start date
01/10/2015
Overall trial end date
31/03/2016
Reason abandoned
Eligibility
Participant inclusion criteria
1. Participant is willing and able to give informed consent for participation in the study
2. Male, aged 18 years or above
3. Diagnosed with haemophilia A or B
Participant type
Patient
Age group
Adult
Gender
Male
Target number of participants
50
Participant exclusion criteria
Concomitant use of pro-haemostatic agents such as tranexamic acid or anti-coagulant agent
Recruitment start date
01/10/2015
Recruitment end date
31/03/2016
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Oxford Haemophilia & Thrombosis Centre
Churchill Hospital
Old Road
Headington
Oxford
OX3 7LE
United Kingdom
Funders
Funder type
Not defined
Funder name
Blood Coagulation and Research Fund, Oxford Haemophilia and Thrombosis Centre (OHTC)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
This study will be published as part of a MSc thesis and will also be submitted for publication as a short report in a peer reviewed journal. We will intend to publish the laboratory data within 12 months of completing the study.
IPD sharing statement
The datasets generated during and/or analysed during the current study are not expected to be made available as consent was not obtained from the patients.
Intention to publish date
31/03/2017
Participant level data
Not expected to be available
Results - basic reporting
Publication summary
2018 results in: https://www.ncbi.nlm.nih.gov/pubmed/29468639