Ann: Successful Competitive Drug Evaluation in Animals, page-20

I wonder if PYC's peers read-outs are measuring the "retinal pigment epithelium/choroid layer", which is the deepest cellular layer of the retina….

Tony, if the peers are measuring delivery to the RPE/choroid layer, they’re not disclosing it.

During the conference today, Rohan mentioned that both Wave Therapeutics and ProQR haven’t given a readout for exon-skipping in RPE cells in their published results. You’d think that if they had managed to get all the way through to the RPE cells, they’d report it.

Here’s the % transcript change results reported by PYC in its 27 June announcement.



And here’s a diagram of the retinal layers.




ProQR simply reported that in its preclinical mouse study of their ASO therapy (QR-110) for the inherited retinal disease, LCA, the drug was detectable “in the ONL at both 14 and 60 days post-dose”.

In the second diagram, the location of the Outer Nuclear Layer (ONL), respective to the retinal pigment epithelium/choroid layer, is clear.

I believe that the “neural retina” referred to in PYC’s %Transcript Change diagram corresponds with the layer that finishes at the outer limiting membrane.