Nightstar Therapeutics has initiated a Phase III registrational trial to evaluate the safety and efficacy of NSR-REP1 in patients with choroideremia.
The STAR trial aims to enrol around 140 patients across 18 surgical centres in the US, Europe, Canada and South America.
Under the trial, patients will be randomised into three study arms. In the first arm, 56 patients will be given a high-dose of NSR-REP1 in one eye. A total of 28 patients will receive a low-dose of NSR-REP1 in one eye in the second study arm, and 56 patients will not receive treatment in the third arm.
Patients in the STAR trial are expected to be recruited primarily from an existing Nightstar-sponsored natural history observational study (NIGHT study).
The trial’s primary endpoint is the proportion of patients with an improvement of at least 15 ETDRS letters from baseline in visual acuity at 12 months after treatment. Patients in the high-dose treatment arm will be compared with patients in the control arm.
Nightstar Therapeutics CEO Dave Fellows said: “The initiation of this first-ever Phase III trial for the treatment of choroideremia is a major milestone for Nightstar and a tremendous step forward for patients otherwise at risk of blindness due to this devastating disease.
“We are very encouraged by the responses we have seen to-date following treatment with NSR-REP1. This accomplishment demonstrates our team’s ability to successfully advance important gene therapies.”
Nightstar further noted that data from 32 patients treated with NSR-REP1 across four open-label Phase l/ll clinical trials have demonstrated that more than 90% of the treated patients maintained or improved their visual acuity over a one-year follow-up period.
NSR-REP1 features an AAV2 vector containing recombinant human complementary DNA (cDNA), which is designed to produce REP1 inside the eye.