- 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
- QR-421a is the second ophthalmology program where clinical activity was predicted by translational models, further validating the platform
- COVID-19 pandemic expected to impact timelines for the pipeline
- ProQR anticipates its cash runway will fund operations into H2 2022
LEIDEN, Netherlands & CAMBRIDGE, Mass., March 31, 2020 (GLOBE NEWSWIRE) -- March 31, 2020 -- ProQR Therapeutics N.V. (Nasdaq: PRQR) (the “Company”), a company dedicated to changing lives through the creation of transformative RNA therapies for severe genetic rare diseases, today announces positive findings from a planned three-month interim analysis of its Phase 1/2 Stellar trial of QR-421a in adults with Usher syndrome and non-syndromic retinitis pigmentosa (nsRP) due to USH2A exon 13 mutations. The Company is also providing an update on business operations in relation to the COVID-19 pandemic. Management will host a conference call today at 8:15 am ET.
“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,” said David Rodman, M.D., Executive Vice President of Research and Development of ProQR. “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. Importantly, these data represent the second program from our ophthalmology pipeline that is supported by preclinical predictions from human retinal organoids, providing further validation of our translational approach and platform technology.”
Phase 1/2 Three-Month Interim Analysis
The interim analysis (IA) is based on nine and three month data from the first and second dose cohorts, respectively, of the Stellar Phase 1/2 clinical trial of QR-421a, an investigational RNA therapy. The Stellar trial is a randomized, single ascending dose, global multicenter, longitudinal, 24-month study, involving active versus sham procedure. The first two cohorts include a total of 14 subjects (ranging from 24-65 years in age), of which eight received a single dose of QR-421a and six received a single sham procedure for masking. Six subjects were enrolled in the 50 µg cohort (“low dose”), of which four received treatment and two were randomized to sham; eight patients were enrolled in the 100 µg cohort (“mid dose”) of which four received treatment and four were randomized to sham. The population varied in disease characteristics with both Usher syndrome (n=6) and nsRP (n=8) affected subjects included, genetic background with both homozygous (n= 4) and heterozygous (n=10) subjects for USH2A exon 13 mutations, and visual impairment at baseline ranging from mild to severe.
Key initial findings include the following:
Safety data: Across both cohorts thus far, QR-421a was observed to be generally well tolerated with no serious adverse events noted. Efficacy data:, In the six sham treated subjects (two followed for 9 months and four for 3 months), outcome measures demonstrated no consistent pattern of response above the “noise” level. In contrast, two of eight QR‑421a-treated patients (one each in the 50 µg and 100 µg dose cohorts) demonstrated benefit across multiple concordant outcome measures.
- Responder 1: One of four treated patients in the low dose group was classified as a responder, with onset of action observed by the 3 month visit. Benefit was maintained for 6 months or longer, which is consistent with the expected half-life of QR-421a in photoreceptors. This Usher syndrome patient was homozygous for USH2A exon 13 mutations and had moderate visual impairment at baseline (peripheral vision affected). Concordant benefit was observed across multiple relevant measures appropriate to the severity of the patient’s disease, including full field stimulus threshold test (FST) [deterioration by 5 dB in untreated eye, treated eye stable], dark adapted chromatic (DAC) perimetry [15 dB.steradian improvement in peripheral sensitivity in treated eye,