The CLASH trial is a randomized, controlled, open-label, phase II clinical trial with blinded outcome assessment (PROBE) to assess pharmacodynamic efficacy and safety of eculizumab in patients with aSAH.
Patient population and setting
Patients 18 years or older with a confirmed aSAH admitted <12 hours after ictus to the University Medical Center Utrecht (UMC Utrecht), a tertiary referral center.
Inclusion and exclusion criteria
The inclusion and exclusion criteria are presented in Table I.
A block randomization is used to randomize patients. Patients are randomized by the investigators via a centralized secured website after informed consent from the patient or legally authorized representative is obtained. Patients are allocated 1:1 to either: 1) the intervention arm; or 2) care as usual.
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. We decided on repeated drug administration with a high dose of eculizumab to prevent a wash-out effect and because the C5a concentration in the cerebrospinal fluid (CSF) of aSAH patients is >1400 times increased one day after ictus compared to the C5a concentration in CSF from patients with unruptured intracranial aneurysms. 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 swaps are performed weekly in the intervention group during in-hospital stay to test for fungus or yeast carriership/colonization and (multi-) drug resistance. In consultation with the microbiologist and infectious disease specialist, prophylactic treatment will be switched if: 1) swaps are positive for micro-organisms that require treatment and are not covered by our prophylactic regimen and; 2) resistant microbial phenotypes are found.
Data collection and management
Data collection is the same for the intervention- and control group (Figure 2). Each patient is assigned a code upon randomization. The decryption key will be stored securely and is only accessible by the investigators. All coded data will be collected in an Electronic Case Report Form (E-CRF). Samples are de-identified and stored under UNI EN ISO 9001: 2015 regulations.
The primary outcome is C5a concentration in CSF on day 3 after ictus. CSF is obtained by either lumbar puncture or sampling from an external lumbar- or ventricular drain. The use of coded samples will allow blinded measurement of C5a concentration by the laboratory technician. The CSF and blood sampling, processing, storage and immunoassays are described in Additional File 2. Secondary outcomes are listed in Table 2.
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 meningitis, CSF culture proven.
- Patients with meningococcal sepsis, blood culture proven.
- Other medical reasons for which the treating physician or investigator deem it necessary to discontinue treatment.
If treatment with eculizumab is halted, other study procedures will continue according to study protocol.
Sample size estimates
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.
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 Hemorrhage (PAASH) scale and the median Hijdra score differ between the intervention and control 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 analyzed 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 World Federation of Neurosurgical Societies (WFNS) score and modified Ranking Scale (mRS) score.
Data monitoring body
An independent data safety monitoring board (DSMB) will oversee safety and overall conduct of the CLASH trial. Safety will be examined by ongoing monitoring of SAEs, and Suspected Unexpected Serious Adverse Reaction (SUSARs), and by an interim analysis based on SAE reporting, outcome, or case-fatality after inclusion of 20 patients. 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. In addition, a contract research organization will audit trial conduct following the approved monitor plan.