What happened

Shares of ProQR Therapeutics N.V. (NASDAQ:PRQR) were up 16% as of 3:48 p.m. EDT on Monday. ProQR didn't report any new announcements, but the biotech's update last Wednesday from a phase 1/2 clinical study -- of RNA medicine QR-110, in treating Leber congenital amaurosis type 10 (LCA10) -- still had investors fired up.

In its announcement last week, ProQR stated that patients receiving QR-110 experienced clinically meaningful responses in both visual acuity and ability to navigate a mobility course after three months of treatment. The experimental drug also appeared to be tolerated relatively well by patients, with no serious adverse events reported.

The raised yellow letters RNA against a black background

Image source: Getty Images.

So what

ProQR Therapeutics' phase 1/2 results justify the stock's big jump, in my view. LCA10 is the leading cause of genetic childhood blindness, with around 2,000 individuals known to have the disease. Currently, there are no approved treatments for LCA10 and no other drug in clinical development other than QR-110.

Shares of ProQR skyrocketed last week on the news from the study. What makes the continued momentum today especially noteworthy is that the company announced a stock offering of 5.75 million shares at $15.75 per share late last week. Although this price tag is well below the current share price, and despite the dilution in the value of existing shares caused by the stock offering, ProQR stock continues to rise. That underscores the enthusiasm among investors for the biotech's potential.

ProQR stated that it will not administer a higher dose of QR-110 to patients in the phase 1/2 study, and is halting enrollment in the study after the positive results announced last week. The biotech now plans to initiate a registrational phase 2/3 clinical study in the first half of 2019.

Now what

The main thing for investors to do now with ProQR Therapeutics is to sit back and wait. There don't appear to be any roadblocks that would prevent the company from advancing QR-110 to a pivotal study next year as planned. If that study goes well, ProQR might not be too far away from winning approval for its RNA drug.

There is one other thing that investors will want to monitor, though. Although there are no other drugs in clinical development for treating LCA10 right now, that could soon change. Editas Medicine expects to file an Investigational New Drug (IND) application to begin clinical testing of its CRISPR-based gene-editing therapy for LCA10 in October.

It's possible that ProQR Therapeutics' first-mover advantage in LCA10 might not last too long. Still, ProQR enjoys a nice head start for now, and could see its stock move even higher.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.