ThromboGenics announced positive data from a phase 1/2 trial assessing the safety and tolerability of THR-317, an experimental treatment for diabetic macular edema (DME).

THR-317 is a recombinant humanized monoclonal antibody directed against human placental growth factor (PIGF), a member of the VEGF subfamily. Preclinical models have demonstrated that anti-PIGF has anti-angiogenic, anti-edema, and anti-inflammatory properties.

Conducted in Czechia, Hungary, and Slovakia, the trial (NCT03071068) enrolled 49 patients with diabetes, of which 40 were treatment naïve and 9 had previously demonstrated suboptimal response to anti-VEGF therapy. Patients were randomized to 3 monthly injections of 4-mg or 8-mg THR-317.

The Belgium-based biotech reported initial improvements in best-corrected visual acuity for the treatment-naïve group. Thirty days after the last intravitreal anti-PIGF administration, 30% of patients in the 8-mg group showed a 15-letter gain or greater from baseline vs 5.3 % in the 4-mg group.

No dose-limiting toxicities or relevant adverse events were reported at either dose.

According to ThromoGenics, the findings support further study of THR-317 combined with anti-VEGF therapy. The company expects the next clinical trial to begin in the second quarter of 2018.