Clinical Trial Failure Risk: Clinical trials for lead candidates like sepofarsen or ultevfarsen may not meet primary or secondary endpoints, be halted due to safety concerns, or show insufficient efficacy, leading to program discontinuation and significant financial loss.

Regulatory Approval Uncertainty Risk: Even with positive clinical data, ProQR may face challenges in obtaining marketing approval from regulatory bodies like the FDA or EMA, which could delay or prevent the commercialization of its product candidates.

Intense Competition Risk: The therapeutic areas ProQR targets, particularly rare inherited retinal diseases, are highly competitive, with larger pharmaceutical companies and other biotechnology firms developing competing treatments, potentially limiting ProQR's market share or pricing power.