ProQR Announces Positive Top-Line Results from the Phase 1/2 Study of Sepofarsen in LCA10 Patients

• Reported rapid, significant and durable improvements in vision at twelve months
• Concordant improvement in key secondary outcome measures
• The target registration dose of sepofarsen was well-tolerated with a favorable benefit/risk profile
• Strengthens confidence in the ongoing Phase 2/3 pivotal study, top-line data expected first half of 2021
• Management to host a conference call today at 8:00 a.m. ET

LEIDEN, Netherlands and CAMBRIDGE, Mass., Oct. 10, 2019 (GLOBE NEWSWIRE) -- ProQR Therapeutics N.V. (Nasdaq:PRQR), a company dedicated to changing lives through the creation of transformative RNA medicines for severe genetic rare diseases, today announced positive top-line results from the PQ-110-001 study, a Phase 1/2 dose range finding, first-in-human trial of sepofarsen (QR-110) in patients with Leber’s congenital amaurosis 10 (LCA10) due to the p.Cys998X mutation in the CEP290 gene.

“We reported today that patients receiving sepofarsen had a clinically meaningful improvement in vision, and in some cases the patient’s vision improved to a level that could be deemed life changing. This is very encouraging for the LCA10 community and the Inherited Retinal Disease community as a whole,” said Stephen R. Russell, MD, Schrage Professor of Ophthalmology and Visual Sciences and Principal Investigator at the University of Iowa. “LCA10 is a severe inherited retinal disease that leads to blindness, and for which there is currently no treatment.”

David Rodman, M.D., Executive Vice President of Research & Development of ProQR, said, “We are very pleased with the data reported from the Phase 1/2 study, in which LCA10 patients treated with sepofarsen experienced a rapid and durable improvement in vision. The top-line data from this study strengthen our confidence in the design of the ongoing Phase 2/3 trial, which could be the sole registration trial for the sepofarsen program. We appreciate the patients’ and medical communities’ ongoing support for the sepofarsen clinical studies, and we will continue to work with the regulators to advance this program as efficiently as possible.”

Top-line results from the Phase 1/2 trial

Based on positive 3-month interim results from the Phase 1/2 trial (Nature Medicine 2018) the Phase 2/3 Illuminate trial was initiated earlier this year. The 12-month top-line results from the Phase 1/2 trial that will be presented today confirm durable activity of sepofarsen for up to one year in patients with LCA10. Furthermore, the results support the assumptions used in the design and powering of Illuminate, including:

• the target registration dose (80 µg with a 160 µg loading dose) was associated with a clinically meaningful and statistically significant improvement in vision and had a favorable benefit/risk profile,
• a six-month dosing frequency, as used in Illuminate, was associated with durable improvements in vision,
• the response observed at 12 months in the target registration dose was equal to or greater than the response at the 3-month interim analysis,
• and subjects with better vision than light perception (BCVA> LogMAR 3.0) at baseline, the study population in Illuminate, were more likely to respond to treatment with sepofarsen.

Table: Change from baseline in treated eye