R&D Forum Recap; A Leader in Retinal Disease Continues Forging Ahead

Research evidence excerpt

R&D Forum Recap; A Leader in Retinal Disease Continues Forging Ahead

June 16, 2026

○The relevant RSH12 knockout mouse model doesn't share

the retinal phenotype with humans but is susceptible

to bright light induced retinal degeneration. Preventative

administration of RDH12 gene therapy was effective (salvage

treatment did not appear to be) implying earlier treatment is

better in animal models, which we assume is probably also

true in humans given the more rapid disease progression

compared to other IRDs.

●MERTK (~2,600 U.S. prevalence). Gene encodes a "metabolic

gatekeeper in the retina", which is expressed by RPE and involved

in phagocytosis of photoreceptor discs. Thus, therapeutic approach

leverages known vector (AAV2, used in Luxturna) and RPE-specific

promoter technology. Mutations constitute 2% of all retinitis

pigmentosa (RP) cases. Because the gene is involved in photoreceptor

function, it makes MERTK quite amenable to measuring functional vs.

anatomical endpoints (structure of retina is preserved in early disease

stages despite significant functional loss). Clinical trial starting 1Q27.

○We are aware of one precedent gene therapy trial (N=6, Phase

1 in Saudi Arabia) published in 2013 where 3 of 6 patients

treated improved vision (by 5 letters) and 3 were stable after 2

years followup (see here and here) of whom only 1 was durable

(here).

●RHO (~8,800 U.S. prevalence). Gene encodes rhodopsin, critical

for phototransduction (and whose mutation and misfolding causes

photoreceptor degeneration). RHO mutations are the most common

cause of autosomal dominant RP (20-30%), thus this is not an ultra-

rare IRD. RHO mutations first present as night blindness, with central

vision loss following later (i.e., this is another IRD where prolonged