Trial Review

The ANZCTR website will be unavailable from 1pm until 3pm (AEDT) on Wednesday the 30th of October for website maintenance. Please be sure to log out of the system in order to avoid any loss of data.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12622001059752
Ethics application status
Approved
Date submitted
6/06/2022
Date registered
29/07/2022
Date last updated
29/07/2022
Date data sharing statement initially provided
29/07/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
The Butterfly study. A trial assessing acceptability and safety of using a subcutanous catheter to administer enoxaparin (Clexane) in patients requiring long-term therapy for treatment or prevention of blood clots.
Scientific title
A prospective crossover trial assessing safety and efficacy of subcutaneous catheters vs subcutaneous injections for enoxaparin administration in patients requiring long-term therapy for either treatment or prophylaxis of blood clots.
Secondary ID [1] 307292 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Deep Vein Thrombosis (DVT) 326581 0
Pulmonary Embolism (PE) 326582 0
Venous Thromboembolism (VTE) 326604 0
Condition category
Condition code
Blood 323826 323826 0 0
Clotting disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A prospective crossover trial comparing enoxaparin (Clexane) therapy using subcutaneous injections (current standard of care) and a subcutaneous indwelling catheter (which can remain in place up to 7 days).

This is a non-randomised trial, therefore all participants will have a subcutaneous catheter inserted, and then revert back to subcutaneous injections (the current standard of care).
The trial period will run over approximately 3 weeks. The subcutaneous catheter will be inserted on day 1 and remain in place for 7 days (unless removal is required before this time). Participants will then continue to administer enoxaparin by subcutaneous injections.

All participants will be receiving enoxaparin by subcutaneous injections, and require ongoing therapy for a minimum of 4 weeks from study entry. Patients on either therapeutic (1mg/kg once or twice daily) or prophylactic enoxaparin (20mg, 40mg or 60mg) therapy will be included.

The subcutaneous catheter will be inserted by nursing staff, and there will be 3 reviews (1 nursing only, 2 nursing and medical review) over the 7 day period using the catheter to assess the site and participant. Participants will be taught to self-administer enoxaparin using the subcutaneous catheter. There will be a nurse and doctor available by telephone on other days to trouble-shoot or answer any questions.

Peak anti-Xa activity will be measured at 3 timepoints (Days 2, 5 and 7) with the subcutaneous catheter. The catheter will then be removed and they will continue on subcutaneous injections for the remainder of the trial follow-up period with 2 further peak anti-Xa levels measured following a period of 5 days using subcutaneous injections.

Participants will be closely monitored for both thrombosis and bleeding during the period of using the subcutaneous device (3 in person assessments and additional phone calls as required), and monthly by telephone for 3 months after.

Patient and nursing assessments will be completed throughout the 3 week study period to assess acceptability of, and any complications associated with subcutaneous catheters.

Intervention code [1] 323742 0
Treatment: Devices
Comparator / control treatment
Crossover trial - participants will act as their own controls. The comparator group will be enoxaparin administration via subcutaneous injections (the current standard of care).
Control group
Active

Outcomes
Primary outcome [1] 331614 0
Therapeutic enoxaparin arm:
Proportion of patients with mean peak anti-Xa levels within range (0.5-1.2 U/mL) across both subcutaneous catheter and subcutaneous injection arms determined by blood tests measured 3-4 hours post enoxaparin dose at the specified timepoints (days 2, 5, 7 for subcutaneous catheter; 2 and 5 for subcutaneous injections).
Timepoint [1] 331614 0
12 months post intervention commencement.
Primary outcome [2] 331615 0
Prophylactic enoxaparin arm
Proportion of patients within the expected anti-Xa (range 0.2-0.5U/mL) determined by blood tests measured 3-4 hours post enoxaparin dose at the specified timepoints (days 2, 5, 7 post subcutaneous catheter insertion; days 2 and 5 of subcutaneous injections following a 5 day crossover period).
Timepoint [2] 331615 0
12 months post intervention commencement.
Secondary outcome [1] 410551 0
The proportion of patients in whom the catheter remains in for the full 7 days as assessed by medical and nursing review
Timepoint [1] 410551 0
12 months post intervention commencement.
Secondary outcome [2] 410648 0
Therapeutic arm
Number of participants with mean peak anti-Xa measurements demonstrating >50% difference or 0.4 absolute difference in the mean peak anti-Xa between day 2 vs day 5 (and day 7 in those applicable post subcutaneous catheter insertion) as measured by blood tests measured 3-4 hours post enoxaparin dose
Timepoint [2] 410648 0
12 months post intervention commencement.
Secondary outcome [3] 410649 0
Feasibility and acceptance of subcutaneous catheters, as assessed by an in house quality of life/patient satisfaction survey
Timepoint [3] 410649 0
12 months post intervention commencement. This will be assessed a days 5 or 7 of subcutaneous catheter insertion (depending on whether the catheter remains in situ for 5 or 7 days), and at the end of the study period.
Secondary outcome [4] 410650 0
Proportion of participants experiencing complications from the subcutaneous catheter, assessed on days 2, 5, and day 7 post catheter insertion where applicable, by an in house adaptation of the modified PIVC (peripheral intravenous cannula) miniQ score
Timepoint [4] 410650 0
12 months post intervention commencement. Individual patient assessments will be performed during the study period on days 2, 5 and 7 post insertion of the subcutaneous catheter.
Secondary outcome [5] 410651 0
Participant preference for a single subcutaneous catheter vs 2 catheters in those receiving twice-daily enoxaparin therapy assessed by a study-related questionnaire
Timepoint [5] 410651 0
12 months post intervention commencement. This will be assessed at day 7 post subcutaneous catheter insertion.
Secondary outcome [6] 410652 0
Prophylactic arm
Proportion of participants with an absolute difference in mean peak anti-Xa activity of 0.15 between both methods of administration as assessed by blood tests to assess mean peak anti-Xa activity at days 2, 5, and 7 post-subcutaneous catheter insertion, and days 2 and 5 post-commencement of subcutaneous injections
Timepoint [6] 410652 0
12 months post intervention commencement.

Eligibility
Key inclusion criteria
- Adults 18 years or older and able to provide informed consent currently receiving either prophylactic or therapeutic dose enoxaparin
- Stable on current enoxaparin dose for at least one week
- Anticipated duration of enoxaparin therapy 4 weeks or longer
- Able to demonstrate competency at self-injecting via subcutaneous catheter
- No risk of major bleeding, as per clinician discretion
- Anti-Xa levels in those requiring them as per standard of care prior to commencement of study
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
- Unable to provide informed consent
- Dialysis dependent renal failure
- Inability to comply with testing and follow-up requirements
- Contraindication to anticoagulation therapy
- Acute thrombosis (within 4 weeks of diagnosis)
- Risk of major bleeding necessitating regular anti-Xa levels to assess anticoagulation dose
- Those requiring enoxaparin dose adjustment for off-target anti-Xa levels
- Upcoming surgery or procedure during the timeframe of the study
- Use of other anticoagulant therapies (see prohibited medications)

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
Calculation of difference in anti-Xa activity between each method of administration assessed as both percentage difference, and proportion of patients within expected range.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
15/08/2022
Actual
Date of last participant enrolment
Anticipated
30/07/2023
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
40
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 22497 0
Monash Medical Centre - Clayton campus - Clayton
Recruitment postcode(s) [1] 37732 0
3168 - Clayton

Funding & Sponsors
Funding source category [1] 311585 0
Hospital
Name [1] 311585 0
Monash Health
Country [1] 311585 0
Australia
Primary sponsor type
Hospital
Name
Monash Health
Address
246 Clayton Road, Clayton, Victoria 3168
Country
Australia
Secondary sponsor category [1] 313023 0
None
Name [1] 313023 0
Address [1] 313023 0
Country [1] 313023 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311035 0
Monash Health Research
Ethics committee address [1] 311035 0
Ethics committee country [1] 311035 0
Australia
Date submitted for ethics approval [1] 311035 0
23/02/2022
Approval date [1] 311035 0
16/05/2022
Ethics approval number [1] 311035 0
77086/RES-22-0000-104A

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 119766 0
Dr Emma Leitinger
Address 119766 0
Haematology Department, Monash Health, 246 Clayton Road, Clayton, Victoria 3168
Country 119766 0
Australia
Phone 119766 0
+61 03 95944292
Fax 119766 0
Email 119766 0
[email protected]
Contact person for public queries
Name 119767 0
Emma Leitinger
Address 119767 0
Haematology Department, Monash Health, 246 Clayton Road, Clayton, Victoria 3168
Country 119767 0
Australia
Phone 119767 0
+61 03 95944044
Fax 119767 0
Email 119767 0
[email protected]
Contact person for scientific queries
Name 119768 0
Emma Leitinger
Address 119768 0
Haematology Department, Monash Health, 246 Clayton Road, Clayton, Victoria 3168
Country 119768 0
Australia
Phone 119768 0
+61 03 95944292
Fax 119768 0
Email 119768 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
All data will be de-identified before analysis and will not be published.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
16321Informed consent form  [email protected]
16322Study protocol  [email protected]



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.