ThromboGenics reports positive results from phase 2b trial of microplasmin in vitrectomy

LEUVEN, Belgium — ThromboGenics has announced positive results from a phase 2b trial evaluating the safety and efficacy of microplasmin in vitrectomy.

The randomized, double-masked, placebo-controlled, dose-ranging MIVI III (Microplasmin for vitreous injection) trial evaluated three preoperative doses of microplasmin — 25 µg, 75 µg and 125 µg — vs. placebo administered to 125 patients scheduled for vitrectomy at 19 centers across the United States.

All doses were administered 7 days before surgery, and visual acuity was measured 35 days after administering microplasmin or placebo, the release said.

According to study results, the 125 µg dose was the most effective concentration of the drug; 10 of the 32 patients in the 125 µg group had achieved resolution of their underlying disease without the need for vitrectomy. In addition, visual acuity had improved in these patients by an average of 6.9 letters.

Conversely, only one of 31 patients in the placebo group achieved resolution of disease without surgical intervention, while five of 33 patients in the 75 µg group did not need vitrectomy.

Visual acuity had improved by an average of 4.7 letters in all patients who received microplasmin, the authors noted, compared with 0.1 letters in the placebo group.

Compared with placebo, the use of microplasmin was associated with a reduced amount and duration of suction needed to achieve posterior vitreous detachment in patients who progressed to surgical intervention, according to the study.

ThromboGenics plans to proceed with a phase 3 clinical development program evaluating the 125 µg dose of microplasmin following a meeting with the U.S. Food and Drug Administration later this year.