The Clomethiazole Acute Stroke Study in tissue-type plasminogen activator-treated stroke (CLASS-T): final results

To assess the safety of tissue-type plasminogen activator (t-PA) plus clomethiazole in patients with acute ischemic stroke and determine the feasibility of combination stroke therapy.

Clomethiazole is a neuroprotectant that appeared to improve outcome in patients with clinical deficits of a major stroke (total anterior circulation syndrome [TACS]) in a previous study, the Clomethiazole Acute Stroke Study (CLASS). Combining a neuroprotectant such as clomethiazole with thrombolysis may augment the beneficial effects of the two agents. CLASS-t-PA (CLASS-T) was a pilot study to explore the safety of the combination and the feasibility of performing combination treatment in the setting of acute ischemic stroke.

In a randomized, double-blind design (stratified for age, severity at admission, and time since onset of stroke), all patients received 0.9 mg/kg t-PA beginning within 3 hours of stroke onset and then either 68 mg/kg clomethiazole (n = 97) IV over 24 hours or placebo (n = 93) beginning within 12 hours of stroke onset. Patients were followed for 90 days. The main measures of safety were mortality and serious adverse events, and the main measure of functional outcome was the Barthel Index.

The number of serious adverse event reports was 47 in the clomethiazole group and 48 in the placebo group. Death during the 90 days after treatment occurred in 15 clomethiazole and nine placebo patients (p = 0.26). Sedation was reported as an adverse event during therapy in 42% of clomethiazole patients vs 13% of placebo patients. The proportion of patients with TACS was 53% in the clomethiazole group and 41% in the placebo group. In the TACS subgroup, 52.9% of the clomethiazole patients scored a Barthel Index greater than 60 vs 44.7% of placebo patients (odds ratio 1.39; 95% CI 0.60 to 3.23).

In this pilot study, there were no safety concerns related to the combination of t-PA and clomethiazole. The combination paradigm proved feasible, although many patients received clomethiazole several hours after thrombolysis; future studies must require prompt administration of the neuroprotectant either before or during administration of the thrombolytic. Patients with major strokes (TACS) may have the potential to benefit from the combination of t-PA and clomethiazole.