This study will be conducted at the University Medical Centre Utrecht (UMC Utrecht), a tertiary referral centre.
The inclusion and exclusion criteria are presented in Table I.
Who will take informed consent?
The physician on call will contact the investigators if an eligible patient is admitted. Written informed consent to participate in the study will be asked from the patient or legally authorized representative after the diagnosis is discussed with the patient and/or the legally authorized representative. Consent is asked by the physician on call or investigators. If the physician on call is too busy, one of the investigators will come to the hospital to ask for consent. The consent form includes information about the study’s rationale, study procedures, and possible benefits and risks. If it will not be possible to obtain consent and administer eculizumab <12 hours after ictus, the patient and/or legally authorized representative will not be approached for trial participation. The patient or representative will receive as much time as needed to decide about trial participation. However, it is noted during the conversation with the patient and/or family member that trial participation can only take place if inclusion <12 hours after ictus is possible.
Additional consent provisions for collection and use of participant data and biological specimens
Informed consent is asked for the collection and use of participant data and biological specimens. No ancillary studies will be conducted.
Explanation for the choice of comparators
The comparator group in our study are patients with SAH who receive care as usual. No placebo treatment and no standard antibiotics or antifungal therapy is administered to the comparator group unless clinically indicated. Although we would have preferred to make use of a placebo comparator for eculizumab, it was not possible to manufacture placebo eculizumab, ciprofloxacin and fluconazole infusions in our hospital within a reasonable time window and reasonable costs. In addition, because this trial is a phase II proof-of concept trial with a primary outcome based on laboratory parameters, the absence of a placebo treatment in the comparator group will not affect our primary outcome.
The intervention consists of intravenous infusion with eculizumab 1200 mg at three different time points: <12 hours, on day 3, and day 7 after ictus (Figure 1). The day of ictus is defined as day 1. To decrease the risk of (meningococcal) infection due to eculizumab treatment, patients in the intervention group receive prophylactic treatment with ciprofloxacin during the first 4 weeks after ictus. During the recruitment phase, after inclusion of the 6th patient, we changed our protocol based on a serious adverse event (SAE) that occurred (cerebral fungal infection in patient with external ventricular shunt). After the amendment, patients in the intervention group with a central line or an external ventricular shunt and a positive fungal or yeast culture receive prophylactic ciprofloxacin and fluconazole for the first 4 weeks after ictus. Throat and rectal swabs are performed weekly in the intervention group during in-hospital stay to test for fungus or yeast carriership/colonisation and (multi-) drug resistance. In consultation with the microbiologist and infectious disease specialist, prophylactic treatment will be switched if: 1) swabs are positive for micro-organisms that require treatment and are not covered by our prophylactic regimen and; 2) resistant microbial phenotypes are found.
Criteria for discontinuing or modifying allocated interventions
Treatment with eculizumab will be discontinued in the following events:
- Anaphylactic shock after infusion of eculizumab. In case of a mild allergic reaction the infusion rate can be slowed down.
- Patients with Neisseria meningitidis meningitis, CSF culture proven.
- Patients with Neisseria meningitidis sepsis, blood culture proven.
- Other medical reasons for which the treating physician or investigator deem it necessary to discontinue treatment.
No modifications to the dosing schedule will be performed except when a mild allergic reaction occurs. If treatment with eculizumab is halted, other study procedures will continue according to study protocol.
Strategies to improve adherence to interventions
The investigator visits the trial participants regularly during their in-hospital stay to explain all study procedures, provided the clinical condition allows such an explanation. If the trial participant is discharged, the participant receives an explanation about the importance of adherence to the study protocol and a safety card to inform other physicians about trial participation. After discharge, trial participants are seen at the outpatient clinic by the same investigator, who then again explains all study procedures.
Relevant concomitant care permitted or prohibited during the trial
All concomitant care or interventions are allowed except for the concomitant care listed in the exclusion criteria (e.g. immunosuppressive medication, chemotherapy).
Provisions for post-trial care
Trial participation will be insured by the UMC Utrecht clinical trial participant insurance.
The primary outcome is C5a concentration in CSF on day 3 after ictus. The difference in C5a concentrations between the intervention and comparator group will be assessed (either the difference in mean or median concentrations, depending on the distribution of the data). CSF is obtained by either lumbar puncture or sampling from an external lumbar- or ventricular drain. Secondary outcomes are listed in Table 2. Mean or median scores between the intervention and comparator group will be assessed at various time points (Figure 2) for all secondary outcomes except for the World Federation of Neurosurgical Societies (WFNS) score and modified Ranking Scale (mRS) score for which the proportion of patients with a specific score will be compared.
The time schedule of enrolment, intervention, assessments, and visits for participant can be found in Figure 2.
The sample size calculation is based on a previous study with eculizumab in patients with neuromyelitis optica. In that study, C5 concentration in CSF was measured in 11 patients before and after treatment with eculizumab. In six patients, C5 was undetectable after treatment was started and in the remaining five patients the mean C5 concentration in CSF decreased with 58%. For the CLASH trial, we conservatively assumed an overall reduction of C5 concentration in CSF with 55% and extrapolated this to a similar reduction in C5a concentration in CSF. Based on α=0.05 and β=0.20 and a standard deviation of 50%, 13 patients are needed in each group. The group size will be increased to 20 patients per group, taking into account an assumed mortality rate of 25% and 2 patients per group who refuse a lumbar puncture in a later phase despite giving informed consent earlier.
Eligible study participants are identified by the physician on call. Because consent for trial participation is asked after the diagnosis is discussed, the information about the diagnosis and the trial can be overwhelming for the patient and family. We developed a lay-men 3D medical animation explaining what a subarachnoid haemorrhage is. The medical animation is shown to the patient and/or family on an iPad and facilitates a conversation about trial participation. In addition, the subarachnoid haemorrhage patient association endorsed our clinical trial and information about this trial was posted on their website.
Assignment of interventions: allocation
A computer-generated block randomization is used to randomize patients. No stratification factors were used.
Not applicable, this trial is an open-label trial with blinded outcome assessment.
Patients are randomized by the investigators via a centralized secured website after informed consent from the patient or legally authorized representative is obtained. Assignment occurs computer generated. Directly after randomization, the investigators receives an email with the allocation. Patients are allocated 1:1 to either: 1) the intervention arm; or 2) care as usual.
Assignment of interventions: Blinding
Who will be blinded
The use of coded samples will allow blinded measurement of C5a concentration by the laboratory technician. In addition, functional outcome measured by the mRS score will be conducted by a qualified person who is blinded for allocation. Blinded assessment of infections will be performed by an expert panel consisting of a microbiologist and an infectious disease specialist. Data analysts will not be blinded to allocation, because this trial is a proof-of concept trial with a primary outcome based on laboratory parameters.
Procedure for unblinding if needed
Plans for assessment and collection of outcomes
Data collection is the same for the intervention- and comparator group (Figure 2). Each patient is assigned a code upon randomization by the computer. Data are collected from the electronic patient system and then transferred to an Electronic Case Report Form (E-CRF) by the investigator under the code assigned upon randomization. If data are not available in the electronic patient system, a paper form is used after which the data are transferred to the E-CRF, also under the code assigned upon randomization. The electronic forms are a mix of pre-existing forms (e.g. GCS, NIHSS, mRS, and EQ-5D-5L) and forms designed by the investigator. Data quality checks are performed by a contract research organisation according to the approved monitor plan (25% of all data entered data will be checked). In addition, the E-CRF makes use of reference values where applicable. All data will be stored on a secured server.
Plans to promote participant retention and complete follow-up
As specified in 11c the participant receives a face-to-face explanation about the importance of adherence to the protocol. In addition, participants will be asked if their phone number is valid. Study visits to the outpatient clinic are planned on the same day as the patient’s standard of care appointment at the rehabilitation centre. Participants who choose to leave the trial are asked whether the collected data can be used for this research. If permission is provided, their data will be handled as data from other trial participants. If permission is not provided, their data will be deleted from the E-CRF and the paper forms will be destroyed.
The decryption key will be stored securely and is only accessible by the investigators. Data management procedures can be found in the data management plan provided as Additional File 4.
Data will be pseudonymized to guarantee confidentiality. Pseudonymized patient data will only be accessible for the investigators, the study monitor, and the health authorities, if required. The personal data collected and stored for the purpose of this study will be treated in accordance with the provisions of the General Data Protection Regulation (GPDR: Regulation EU 2016/679). Samples are de-identified and stored under UNI EN ISO 9001: 2015 regulations.
Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use
The CSF and blood sampling, processing, storage and immunoassays are described in Additional File 3.
Statistical methods for primary and secondary outcomes
Primary analysis will be based on the per-protocol principle in which patients with CSF assessments will be included. Patients in the intervention group with CSF assessments are included if they received the first eculizumab infusion.
Groups will be compared with an independent t-test or Mann-Whitney U-test, dependent on the distribution of data. If the proportion of patients categorized according to the Prognosis on Admission of Aneurysmal Subarachnoid Haemorrhage (PAASH) scale and the median Hijdra score differ between the intervention and comparator group, a multivariable logistic regression analysis with adjustment for these variables will be performed.
Inflammatory parameters in the blood and daily Glasgow Coma Score (GSC) will be analysed with a linear mixed model. CSF inflammatory parameters in both groups will be compared by means of an independent t-test or Mann-Whitney U-test, dependent on the distribution of the data. To compare the NIHSS score, cognition, and quality of life, a Chi-square or Fisher’s exact test will be applied. A proportional odds model will be used to assess the effect of eculizumab on WFNS score and mRS score.
An interim analysis will be performed based on SAE reporting, outcome, or case-fatality after inclusion of 20 patients. The DSMB can advise early termination of the trial if there is evidence of severe harm based on SAE reporting, outcome, or case-fatality.
Methods for additional analyses (e.g. subgroup analyses)
Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data
Missing data will not be imputed.
Plans to give access to the full protocol, participant level-data and statistical code
The dataset of this study is not publicly available, but is available from the corresponding author on reasonable request.
Oversight and monitoring
Composition of the coordinating centre and trial steering committee
This is a monocentre trial. The trial steering committee consists of multiple experts in the field of subarachnoid haemorrhage, infectious diseases, and experts who have experience with treatment of patients with eculizumab. The trial steering committee provides guidance for general trial conduct.
Composition of the data monitoring committee, its role and reporting structure
An independent data safety monitoring board (DSMB) will oversee safety and overall conduct of the CLASH trial. The DSMB consists of two neurologists and one clinical epidemiologist. The chair has previous experience in serving on DSMBs and experience in chairing meetings.
Adverse event reporting and harms
Safety will be examined by ongoing monitoring of SAEs, and Suspected Unexpected Serious Adverse Reaction (SUSARs), and by an interim analysis. Listings of infections will be reported every two months to the DSMB chairman. The DSMB can advise early termination of the trial if there is evidence of severe harm based on SAE reporting, outcome, or case-fatality. SAEs that can be expected based on the patient population include rebleeding, per-procedural aneurysm rupture, hydrocephalus, hyponatremia, delayed cerebral ischemia, nosocomial infections, Tersons’s syndrome, epilepsy, and delirium. All AEs, SAEs, and SUSARs will be collected systematically by reviewing the electronic patient system and by reporting of the patient spontaneously or at 4 weeks after ictus. All adverse events will be reported in the supplementary material of the trial’s publication.
Frequency and plans for auditing trial conduct
A contract research organisation will audit trial conduct following the approved monitor plan. This includes 2-3 visits a year in which the in- and exclusion criteria, informed consent forms, source data, and SAEs reporting are verified.
Plans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees)
The coordinating investigator will submit amendments for review to the ethics committee of the UMC Utrecht. Upon approval, all parties involved will be informed about the amendment and the protocol in the clinical trial registry will be updated.
After the clinical trial is completed, an article will be written for publication in an international journal. The results will also be presented at an international conference.