ProQR’s Usher syndrome candidate shows positive interim data
Interim results of a phase 1/2 clinical trial of QR-421a has shown early evidence of activity in Usher syndrome, with 25% of patients experiencing a benefit across outcome measures, ProQR Therapeutics announced in a press release.
The first-in-human, double-masked, randomized, 24-month Stellar study is evaluating the safety and efficacy of a single intravitreal injection of several dose levels of QR-421a in adults who have vision loss due to mutations in exon 13 of the USH2A gene.
Six subjects were enrolled in the low-dose 50 µg cohort, with four receiving treatment and two receiving sham. A mid-dose 100 µg cohort included eight patients, with four receiving treatment and four receiving sham.
Interim data, based on 9- or 3-month data, show two of the eight patients treated with QR-421a, one in each cohort, experienced benefits across outcome measures, the release said.
“The goal of the interim analysis of this 24-month Stellar trial of QR-421a was to assess safety and early signs of efficacy for the purpose of informing next steps in development and future trial strategy,” David Rodman, MD, executive vice president of research and development of ProQR, said in the release. “We are pleased with the current safety profile and are very encouraged by early signals of target engagement and clinical activity supported by concordant benefit observed across multiple outcome measures for 25% of QR-421a-treated patients thus far in this trial. The findings support continuing the trial as planned, with both cohort expansion and dose escalation in order to identify a potential development path to registration.”