Proliferative vitreoretinopathy (PVR) is an eye condition that leads to blindness and can currently only be addressed with surgery. A team led by research hospital Massachusetts Eye and Ear and German biotech CureVac has designed an mRNA therapy that delivered a therapeutic gene transcript to the eyes of rabbits with the disease, reducing the harmful excess of scar tissue that is characteristic of the condition.
The treatment also prevented further scarring in eye tissue collected from PVR patients during surgery and cultured in the lab, and it reduced the harmful growth of blood vessels in a mouse model of wet age-related macular degeneration, the researchers said.
The results were published in Science Translational Medicine on Nov. 27.
PVR can occur after surgery to repair a detached retina and is essentially a proliferation of scar tissue that prevents the retina from successfully reattaching. The only available treatment is to go under the knife again to remove the scar tissue and re-reattach the retina. If not effectively treated, PVR can cause vision loss in the affected eye.
The injected treatment used lipid nanoparticles to deliver an mRNA transcript into the eye that codes for a protein inhibitor of runt-related transcription factor-1 (RUNX1). RUNX1 is up-regulated in PVR and contributes to the out-of-control tissue formation seen in the disease.
Because PVR only occurs after retinal detachment and can be repaired, long-term treatment isn’t needed, the authors wrote in the study. But for long-term targeting of RUNX1 that other diseases might demand, more studies are needed on the safety and efficacy of the mRNA therapy, according to the authors.
As its name suggests, CureVac’s pipeline is led by mRNA vaccines. In July, GSK paid $430 million upfront for full rights to CureVac’s vaccines against influenza and COVID-19. The German firm’s flu and COVID vaccines are in phase 2 trials, while a combination vaccine is in phase 1.
When announcing the GSK deal, CureVac tempered the news by also unveiling a restructuring that put 30% of its employees out of work and extended its cash runway into 2028.