ThromboGenics reports positive results from Phase II stroke trial

The trial showed that microplasmin was generally well tolerated and also provided some preliminary efficacy data. The MITI IV trial was a Phase II, multicentre, randomized, double-blinded, placebo-controlled, ascending-dose clinical trial evaluating the safety and preliminary efficacy of the intravenous administration of microplasmin in 40 patients, four to 12 hours after onset of acute ischemic stroke.

The trial investigated three dose regimens of microplasmin (2, 3, and 4mg/kg total dose) compared to placebo. Clinical outcomes were assessed at seven days and 30 days post-treatment, and at each of these visits neurological assessments were performed.

The study found that microplasmin was generally well tolerated with no evidence of increased bleeding risk; there were no systemic bleeding events reported and there was no evidence of increased rate of bleeding in general, in those patients that had been treated with microplasmin compared to those treated with placebo.

In addition, the study provided some preliminary efficacy results. Approximately 25% of patients treated with microplasmin had reperfusion within eight hours of being treated, this compares with 10% of placebo-treated patients. Moreover, of the patients who had more severe vascular blockages, 33% of patients treated with microplasmin achieved reperfusion compared with 14% of placebo-treated patients.

Due to the small number of patients in this study, neither of these end points were statistically significant. However, the study also showed that microplasmin-treated patients had a statistically significant improvement in the level of damage to the blood brain barrier compared to placebo-treated patients, measured using the marker of matrix metalloproteinase (MMP), the company said. MMP activation plays a crucial role in the pathogenesis of brain edema and hemorrhagic transformation after ischemic stroke.