Nightstar Therapeutics PLC said the U.S. Food and Drug Administration granted regenerative medicine advanced therapy designation to its gene therapy NSR-REP1 for a rare genetic disorder that leads to blindness.

The London-based gene therapy company said that NSR-REP1 is currently being evaluated in a phase 3 trial to treat choroideremia, a genetic retinal disorder characterized by progressive vision loss.

Nightstar said the U.S. regulator's designation was based on clinical data from phase 1/2 trials supporting the maintenance and improvement of visual acuity in choroideremia patients.

A regenerative medicine is eligible for the designation if it is intended to treat, modify, reverse or cure a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug has the potential to address unmet medical needs for such a disease or condition.

The designation includes all the benefits of a breakthrough therapy designation, including eligibility for priority and rolling reviews and accelerated approval from the FDA.