ProQR Therapeutics have released their first interim analysis of its phase 1/2 Stellar trial in adults with Usher syndrome and non-syndromic retinitis pigmentosa (nsRP) due to USH2A exon 13 mutations. The following summary provides an overview of this RNA-based clinical trial including a link for a patient community update document which contains more detailed findings.
These positive findings, with 25% of patients experiencing some improvements, provides much needed hope to the Usher community as well as reassurance that research is happening, and that progress is being made to find a treatment for Usher syndrome.
Summary of Phase 1/2 Interim Analysis of QR-421a for Usher Syndrome Program
A first-in-human clinical trial of QR-421a is ongoing. The Phase 1/2 study, named Stellar, includes adults that experience vision loss due to mutation(s) in exon 13 of the USH2A gene. This Phase 1/2 clinical trial is designed to evaluate the safety and tolerability of QR-421a. Patient benefit will be assessed as well.
Three-months interim findings from Stellar, reported in March 2020, suggested QR-421a given as a single intravitreal injection was safe and well tolerated. QR-421a showed early and encouraging evidence of activity, with 25% of patients showing a benefit across multiple concordant outcome measures and was well tolerated with no serious adverse events. Two of eight participants in the treated groups responded to QR-421a treatment thus far showing benefit in multiple outcome measures.
Across both cohorts thus far, QR-421a was observed to be generally well tolerated with no serious adverse events noted. Based on these early positive findings we will continue the trial as designed at expert centers in North America and select European countries.