ProQR Therapeutics NV (NASDAQ:PRQR) just put out data from its early stage cystic fibrosis (CF) study, and the numbers sent the company’s market capitalization on a nice upside run. At market close on Wednesday, ProQR went for a little over $6 a share. By market open on Thursday, the same shares were priced just shy of $9. This is back down to just over $6.15, however, as markets have capitulated somewhat on digestion of the news and its implications.
Regardless of the now seemingly flat response to the data, we think there’s still plenty of upside run room near term, and looking longer term, ProQR has a good solid base of safety and efficacy date (albeit small in scope) with which to carry into its pipeline maturation.
With this in mind, here’s a look at what we are looking for from the company moving forward, and what the data from the latest release actually means.
So, first, a little bit about the drug. As mentioned it’s a CF target indication, and it’s called QR-010. We’ve actually covered this one on a number of occasions in the past, but for those that missed our previous coverage, here’s a quick run down of how it works.
It’s designed to target a gene called CFTR, which is the gene that is responsible for producing a protein called, not surprisingly, CFTR. CF sufferers have a mutation in their CFTR gene, and this causes the production of a dysfunctional CFTR protein.
The protein is responsible (in healthy patients) for the movement of chloride ions in and out of cells, which is important for the salt and water balance on epithelial surfaces. An imbalance in this process creates the underlying symptoms of CF – specifically, the buildup of mucus on the surfaces of the lungs and airways in the body.
A dysfunctional CFTR protein, therefore, creates the imbalance, and causes the symptoms. This makes it an attractive target for companies looking to cure CF, hence ProQR’s current program.
The drug itself seeks to repair the mutated gene (we won’t go in to too much detail on how, as it’s not really necessary for the purposes of this discussion) and the latest data suggests that it does just that.
Well, in some patients, at least. The mutation in this gene is caused by a number of different mutations, and ProQR was looking at two specifically in this trial. The first, in patients that had two two copies of what’s called an F508 mutation. This is the most common root cause of CF, and was the one (out of the two targets) that the company wanted to hit on most. The second target was patients with one copy of the F508 mutation, plus an additional, different mutation. This was a secondary goal.
The endpoint of the trial was a change in what’s called nasal potential difference (NPD), which is a measurement of ion transfer across the nasal membrane.
In the patients with the two copies of the F508 mutation, NPD reduced, so endpoint hit. In those with one, plus one additional, there was no change versus placebo. So this means the drug looks promising in the largest subset of CF sufferers globally – what’s the downside?
Well, the FDA is never going to accept an NPD endpoint as an approvable indication of clinical benefit. Yes, NPD is related to CFTR function, and CFTR function is related to CF severity, but the agency is going to want to see the drug’s direct impact on some various key symptoms before it is willing to give QR-010 a green light for commercialization.
This, therefore, is what we are looking for going forward.
The latest data paves the way for a phase II trial nicely, and the company is going to be heading into said trial on the front foot, with a solid surrogate indication that its drug is effective. We want to see a CF target as a direct primary in the next trial, preferably lung function, and we think an endpoint hit on this sort of target would be a great bell weather of success for the company going forward.
One to watch, but don’t get carried away.