Time to Stop (TTS) Trial: a trial to investigate early antiepileptic drug withdrawal after pediatric epilepsy surgery

ISRCTN ISRCTN88423240
DOI https://doi.org/10.1186/ISRCTN88423240
EudraCT/CTIS number 2011-005971-18
Secondary identifying numbers N/A
Submission date
28/03/2013
Registration date
08/05/2013
Last edited
08/05/2017
Recruitment status
Stopped
Overall study status
Stopped
Condition category
Nervous System Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
There is no consensus about timing of anti-epileptic drug (AED) withdrawal after pediatric epilepsy surgery. A previous study of 766 children suggested that early withdrawal does not affect long-term seizure outcome, unmasks incomplete surgical success sooner, and prevents unnecessary AED use in many children. The aim of this study is to demonstrate cognitive and behavioral benefits and improvement of quality of life, and confirm safety of early AED discontinuation.

Who can participate?
Patients aged younger than 16 years from participating pediatric epilepsy surgery centers in Europe.

What does the study involve?
Participants are randomly allocated to one of two groups: either an early AED withdrawal group, that starts reduction of AEDs four months after surgery and completes withdrawal within eight months after start of withdrawal, or a late AED withdrawal group, in which tapering off medication starts at 12 months after surgery and completion should be within 20 months after surgery. The primary outcome measure is attention, as measured by reaction time on CPT (Conner's Performance Test). Other neuropsychological domains are assessed by standard neuropsychological testing, as part of standard clinical care. Other outcome measures are seizure recurrences, eventual seizure freedom and cure, behavioral changes and quality of life. In both groups, the latest follow-up time point is 20 months after the start of intended withdrawal (i.e. 24 months in the early group, and 32 months in the late withdrawal group), thus the total follow-up duration of being at risk [without drugs] is identical between groups. Patients are studied in an outpatient clinical setting.

What are the possible benefits and risks of participating?
The study may be beneficial to the patients in the early withdrawal arm, as they are devoid of medication in an earlier postoperative stage. Their cognitive functions might improve and medication related side effects may be less frequent. With regard to the risk assessment, the risk for seizure recurrences in the early withdrawal group is comparable to the late withdrawal group, as patients with known predictors of unfavorable outcome are excluded. The recurrences will only occur earlier during follow up. A recurrence rate of around 30% is expected, comparable to normal clinical practice. Most of the patients regain seizure freedom after restart of antiepileptic drugs, as shown previously and in accordance to current clinical experience.

Where is the study run from?
University Medical Center Utrecht (Netherlands)

When is the study starting and how long is it expected to run for?
January 2014 to January 2019

Who is funding the study?
Dutch National Epilepsy Fund (Netherlands)

Who is the main contact?
Prof. Kees PJ Braun

Contact information

Prof Kees PJ Braun
Scientific

Heidelberglaan 100
room: KC.03.063.0
Utrecht
3508 AB
Netherlands

Study information

Study designRandomised open European multicenter clinical 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 participant information sheet
Scientific titleTime to Stop (TTS) Trial: a randomised controlled trial to investigate early antiepileptic drug withdrawal after pediatric epilepsy surgery
Study acronymTTS Trial
Study objectivesEarly antiepileptic drug withdrawal is beneficial to patients with regard to cognitive outcome.
Ethics approval(s)Medical Ethics Committee of the University Medical Center Utrecht, 24/01/2014, local protocol ID: 13-617
Health condition(s) or problem(s) studiedIntractable epilepsy
InterventionThe Time to Stop trial will compare an early AED withdrawal group, that starts reduction of AEDs four months after surgery and completes withdrawal within eight months after start of withdrawal, with a late AED withdrawal group, in which tapering off medication starts at 12 months after surgery and completion should be within 20 months after surgery.
Intervention typeDrug
Pharmaceutical study type(s)
PhaseNot Applicable
Drug / device / biological / vaccine name(s)
Primary outcome measureThe primary objective of the study is to assess whether early AED withdrawal improves cognitive function, in terms of attention, information processing- and psychomotor speed, memory, language and IQ/DQ scores. Attention will be the main outcome measure, on which the power calculation is based.

Attention deficits (AD) are assessed using a Conner's Performance (Kiddie) test and calculate IQ/DQ scores. The other neuropsychological domains will be assessed by subtests of the intelligence tests. We will compare neuropsychological outcome between the two withdrawal groups at t1 (preoperatively), t2 (at 12 months) and t3 (at 24 months).
Secondary outcome measures1. To confirm safety, in terms of seizure recurrences, long term seizure freedom and cure, of early AED withdrawal. In the randomized trial we determine long-term seizure outcome and cure at 20 months following intended start of AED reduction (being theoretically 'at risk' during an identical time window in both groups). Seizure freedom will be defined as complete seizure freedom for at least one year [Engel 1(3) of International League Against Epilepsy (ILAE) 1-2(4)], and cure as seizure freedom and AED freedom for at least one year. The existence of seizure recurrences will be measured every time the patient visits her/his epileptologist, and if parents call the hospital to report seizure recurrences.
2. To compare behavioural problems between the two withdrawal groups, parents of participants will, at both postoperative neuropsychological test points, complete a Child Behavior Checklist (CBCL) (12 and 24 months postoperatively)
3. To compare quality of life between the two withdrawal groups. Patients will, at both postoperative neuropsychological test points, complete a Pediatric Quality of Life InventoryTM (PedsQL™) and the The Hague Side Effects Scale (HASES) (12 and 24 months postoperatively).
Overall study start date01/01/2014
Completion date01/01/2019
Reason abandoned (if study stopped)Participant recruitment issue

Eligibility

Participant type(s)Patient
Age groupChild
Upper age limit16 Years
SexBoth
Target number of participants180
Key inclusion criteria1. Younger than 16 years at surgery, with focal non-idiopathic epilepsy
2. Native speaker in the language the neuropsychological tests have to be taken
3. Be able to perform a Conner's Performance Test preoperatively (generally that means age > 4 yrs, and IQ > 60)
4. Underwent intentional curative epilepsy surgery
5. After surgery, the treating physician considers withdrawal of antiepileptic drugs (AEDs), with the intention to completely discontinue medication, at whatever point in time.
6. Both the treating physician, the patient, if capable, and the parents agree with randomization in either arm of the study
7. Postoperative seizure freedom was achieved (with the exception of so called running down seizures not outlasting longer than two weeks)
Key exclusion criteria1. A contraindication to be randomized to either of the two withdrawal arms
2. The treating physician does not want to discontinue all AEDs within a maximum time frame of eight months as prescribed in the study protocol.
3. Multifocal MRI abnormalities, incomplete resection of the anatomical or epileptogenic lesion certified before randomisation (if considered necessary by the treating physician by MRI) and, if a postoperative EEG is performed before randomisation, epileptic EEG abnormalities (these being the most important risk factors of seizure recurrence or unfavourable long-term seizure outcome).
4. Use of more than three AEDs at time of surgery. The reason to choose for a maximum of three AEDs is that clinicians would not want to wait 12 months (the late withdrawal arm) to withdraw the first AED in patients that use so many AEDs. Furthermore, withdrawing AEDs within 8 months seems reasonable and feasible for a maximum of three AEDs.
5. Patients who are on a ketogenic diet or have a vagal nerve stimulator implanted.
6. If surgery is primarily intended as tumor surgery and not as epilepsy surgery
Date of first enrolment01/01/2014
Date of final enrolment01/01/2019

Locations

Countries of recruitment

  • France
  • Germany
  • Netherlands
  • Switzerland
  • United Kingdom

Study participating centre

Heidelberglaan 100
Utrecht
3508 AB
Netherlands

Sponsor information

University Medical Center Utrecht (Netherlands)
Hospital/treatment centre

Heidelberglaan 100
Utrecht
3584 CX
Netherlands

Phone +31 (0)88 755 55 55
Email info@umcutrecht.nl
Website http://www.umcutrecht.nl
ROR logo "ROR" https://ror.org/0575yy874

Funders

Funder type

Charity

Dutch National Epilepsy Fund (Netherlands) ref: (08-10)

No information available

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 planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol article protocol 26/10/2015 Yes No

Editorial Notes

08/05/2017: The trial was stopped without any inclusions due to a participant recruitment issue; there are no results to report.

11/11/2014: Austria, Italy, Spain and Turkey were removed from the countries of recruitment.